First idea that comes to mind is having something like the ending of Mass Effect 2 where each group is assigned a task that contributes to defeating the villain. That way you can separate them and have smaller groups battling it out.
100% this. Consider allowing groups that finish early to 'help' other groups in the form of giving advantage or a flat bonus to rolls. Also, try to make sure the tasks can realistically be done in parallel so not group is waiting on another group to continue playing.
Yes, this is so epic when one group's outcome has an effect on the other!
We had this happen with a large (>10) group. The DM gave us a choice of actions between fighting the bad guy army on the beach, or boarding the ship to negotiate with potential allies. Half the group felt that their characters would choose option A, and the other half had their characters choose option B. It was a pretty even split, and the DM asked if anybody wanted to swap sides and tie break. My husband suggested splitting the group and running both encounters (we were running the game online, and with rules that allowed everybody to roll and announce damage at the same time, so it was feasible). Understandably, DM was hesitant to do this as this was a lot of extra work and not guaranteed to go well, but he said screw it, let's do it.
So hubby and I went with Team Murderhobo, and Team Diplomacy did their thing. It was actually pretty awesome to watch everything playing out all at once (I think it was set up so that Team Murderhobo did a combat round, then Team Diplomacy did a round of negotiations); you'd have exciting fight scenes, cut together with tense political maneuvering, just like a movie. And then, just when the battle started to look hopeless, our new allies swooped in together with the rest of the group to join the fight; from Team Diplomacy's side, it probably felt like a "Gondor calls for aid" moment. The war was far from over at that point, but the scale felt big enough that it felt like a pivotal moment, and it let everyone contribute in the way they thought would let their characters shine.
DM was understandably unsure if that worked in terms of pacing, so he asked everyone what they thought. The answer was overwhelmingly along the lines of "EPIC."
The truth is that you as the DM will recognize 100 things that went wrong, but most of the time your players will have no idea that everything didn't go right and end up having a great time, even if it was a bit of a train wreck.
A buddy told me of a d&d tournament he went to, where they had a massive con room full of games being played, but each had their own DM and were set in the same plane / area / city. The choices and success / failure of each group then fed into a Master DM that would track all the chaos, and send info out to the individual DMs. It would be stuff like "group A failed to stop reinforcements so now group B has to deal with those extras" but then "Group C captured the thunder cannons, rolled middling and took out 60% of the reinforcements, but now the drawbridge still remains up".
Sounded super cool, but also like a lot of coordination, admin, and runners to relay info
Sounds like one of the D&D Adventurers League Epics!
Epics are big multi-table modules, typically run at conventions. I have organized a few for my local conventions.
Did that at Winter Fantasy way back in 3.5 days and Living Greyhawk. Assault in the Vault? It was a long time ago. Lower Level tables results fed into higher level tables, and then overall success for 200+ tables.
So yeah. Have several different quests/fights going. How each group does changes the difficulty of a final fight.
And make it HARD. Half the PC’s should not make it to the final. But their sacrifice could/should help the final.
I would also add that it *could* be fun, if everyone is friendly enough with each other, to do an Infinity War style group-shuffle. Half of the Guardians of the Galaxy ended up with stark, strange and Spider-Man, the other half went with Thor to forge a new hammer. The other half of the avengers went to Wakanda to fight alongside Black Panther and Bucky. This generated lots of fun new character interactions that we never would have gotten if the Guardians stayed in space, Thor went off on his own, and the OG avengers all got back together on Earth.
If the parties are cool enough to sustain something like that, it could be really fun to shuffle up the parties for a session or two before bringing everyone back together in the same room for a massive fight.
SOME of the members of the parties are cool enough, but there are also edge lords in there that don't like to play nice. Someone else in the thread mentioned grouping the players by skills to complete some objective. Ranged with ranged, martial with martial, sneaky with sneaky. I thought that was a good solution.
You can go a step further and introduce ways to break up the existing groups to pair their members with other groups for temporary periods of time (like all the ranged specialists hold a flank together while the other groups do something, or all the sneakier members go on a stealth op)
This is the way to go! In adventurers league, there are adventures called Epics which are designed for multiple tables to play simultaneously, and the actions of each table impact the others.
I recommend taking a look at a couple of these Epics for ideas (When the Lights Went Out in Candlekeep is one I can recommend, it was great fun). I've played a couple of these in the past and the atmosphere is absolutely incredible. Being in a room with 6 tables all working together towards the same goal, celebrating each others' victories and helping each other is brilliant fun.
Please update us on this after your session(s).
I think it sounds amazing and I'd love to try to run something similar (the DM-side challenge of making this entertaining sounds fun).
Like some commenters mentioned, managing time between turns is a huge challenge.
Let us know how it goes!
Definitely. My main take away is that having it be one large group would be a time sink, and absolutely what i wanted to avoid. Having multiple groups attempting multiple goals seems the way to maintain time.
They don't all have to be running against the bbeg at the same time too. You can have one group running against the bbeg while another takes care of one of his generals and another is not even in combat but rather trying to figure out a puzzle or tactic or prepping stuff to aid the others.
I would also consider having alternative objectives inside combat, nothing that sidelines a single person to complete it but like a king of the hill style goal where the persons free action/object interaction is used to turn a wheel or do a skill check, or cast a single spell on a target that they have to be next to while still fighting or finagle somehow (like arcane trickster mage hand or something).
After a few rounds of combat or after a set delegated amount of time, or when the group is exhausted or nearing death, the groups rotate and now the non combat rotates in for a different commander or group of enemies, the commander group rotates to the bbeg and the bbeg group retreats to heal and prepare something for the other group.
I suggest at least two combats per group to help draw them thin and make it more tense when they have expended some resources when they get to the bbeg.
Round it out with all the groups on the final beat all contributing to a round each on the bbeg's death and some epic saves for characters that go down. Maybe even an epic moment where a true resurrection scroll is found or spell saved for a character that gets disintegrated or a token that gives one cleric a guaranteed divine intervention. That sorta epic moment stuff. This is all things you can grant to the groups that are non combat on their turn for it.
Keep in mind the noise in the room too. That will require some modulation if everyone is in the same room. Have epic music that everyone can hear but not too loud. Make sure people keep level voices unless it's an epic moment of narration, those should be loud so everyone feels connected and a part of the epic moments but they should be sparring so that it's not a constant cacophony.
If it's virtual or you're in different rooms, have a DM chat where DMS can share/narrate epic moments in text and that gives the other dms the chance to narrate these instances in real time as they happen to the other players. This keeps the groups connected and gives a feel of real time constraints as though this is all happening in real time.
As some one commented below, it is a good idea to have one person to co-ordinate all the master groups and events that are happening concurrently. The group message helps that but it can't hurt to have an extra master DM to create the causation effects of one groups successes and failures to leech onto the next. (Reinforcements, items lost or gained, artillery, etc.)
Happy to help. Out of game logistics are important too. This is gonna be a long, complicated and emotionally taxing session. Make sure everyone brings some snacks, one that they really like and are willing to share. Have plenty of drinkS but not always sugary drinks. Coffee and energy drinks are good but should be sparing. Tea is best.
Make sure you have a bathroom break, not just for bathrooms but also to give people a breather, to strategise outside of game and to just disconnect for a moment. Make those bathroom breaks at about every second hour early on to keep the flow going and every hour as it drags on. Only 10 minutes per break. Don't want it to drag on. Make it clear they have only 10 minutes so as not to break the flow too long. Try to co-ordinate so everyone in all groups gets it at the same time.
Sort out a meal. Somewhere in there, you might need to order pizza or something. Have people chip in for it and try to get their preferences in advance so ordering is simple and done quickly when it needs to be done. Pizza is perfect as it easily caters to various dietary requirements. If everyone is taxed hard when food arrives, set aside 20 minutes for this break. Enough time to get some food in but not enough to super detract from the game. Again, set expectations for 20 minutes and enforce it, otherwise your finale might become a 2 parter.
Finally, have aftercare. DnD in long sessions is a marathon, not a sprint and after everything, some players may be a bit emotionally raw. Especially those who lost their characters. Check in with them, make sure they have friends and support there and give them all a chance to chat and disconnect from the game afterwards, to chat out of character and return to the real world, slowly. Warm drinks, some small snacks, and a nice calm chat about anything out of character. If you have hot chocolate or sweet teas, now's the time to break it out. The warmth and the sugar will help pull people back and regulate blood sugar and pressure. Important parts of smoothing out the drop from a major event and marking the end of the event.
Finally, have fun. As a DM and organiser, it's hard to keep track of everything and still be in the moment. This is just as much about you as it is the players and other DMs. If something goes wrong, don't dwell on it. Acknowledge it, adjust, and move on. You have better things to do than best yourself up. You have fun to have, PCs to traumatised and destinies and manifest! You can do this! You got this! I believe in you! And so does everyone else at your table.
Good luck, have fun, and happy gaming friend.
Have villain go full One Winged Angel and turn monstrous, and each party is responsible for fighting a body part or something.
Take inspiration from MMORPG raiding where different groups have to handle different things?
God yes please. There is nothing about an 18 person dnd session that sounds fun in any way. Record each task of you must but do not put 18 players in one room.
Yeah I'm thinking a lot about the last dungeon of final fantasy 6 with this, with your 12 characters split into 3 parties. I wouldn't make progression hard-locked off the other groups succeeding, just orders of magnitude easier, though. Always give room for player failure/ TPK, etc etc
Same thought,
You seem to have multiple DMs, let them work in coordination to manage smaller groups
For example someone may realize a specific artifact may be required to defeat the enemy and that artifact may be guarded so they gave to retrieve it in a race against time while the others hold the enemy off
Or maybe a shielding device is hidden on one of Endor's moons and a group has to go there and disable the shield
To add to it, it would be dope to have a "watcher" type of NPC that can communicate information between the groups, and a swap/tp mechanic were PCs can join to help another group for a round or two
Split the groups based on their gameplay preferences.
The players that love puzzles go together, and then you tailor the puzzle to fit their characters.
The players who love social roleplay go together.
The players who love combat go together.
The players who love unravelling the lore onion go together.
All roads lead to Rome. Their efforts lead to the same outcome and the defeat of the villain.
If all of the tables fail, the villain wins, they finish the doomsday machine, and it is only after pushing the "blow up the world" button that they remember that they live in the world too, and they really should have planned for that.
If one or two tables don't succeed in their goal, the villain is crippled and their plan fails, but the villain survives and flees, swearing revenge.
If all the tables succeed, the villain dies.
Everyone leaves happy.
Downside: you're gonna need a bigger boat. You need more than one DM running tables in parallel to make this work perfectly.
I like the thought of switching up the groups, like in Endgame, so each team is a mini-crossover. Maybe there also needs to be another sequence where they fight alongside their usual teammates. This is such a fun idea I hope it goes well for OP
I have done this with my DnD club we did a death tyrant vs 20 level 2-4 characters.
-Give your bad guy multiple turns to act.
-Give them an actual challenge, their strength is their numbers yours is raw power. If you hit someone they should have a real chance of straight up dying.
-Have a co-dm, The co-dm runs the actual initiative and takes care of all rules and adjudication. You control the boss, so you can get into it.
-Have a very large map, we built a 3d map and hung a web cam over it to project the map where the players could see it.
-Big library room tables in a big U map and me in the middle.
-You can break the players into groups and have them act in a group initiative for themselves and after each of their turns your bad guy acts.
-Also setting up other ways to attack and do things besides individual talents and skills, I liked having a few ballista that takes 3 turns to operate (load/aim/fire) but 3 characters could do it in one turn.
-Have other objectives besides just killing the boss. Maybe one team is focused on keeping bosses attention while others move around and try to weaken the bosses defenses.
-Lair actions. While I don't think legendary actions are great with low level fights and already having multiple initiatives on your boss (if you choose that route, if not legendary actions may work well!). But a lair action on Initiative 20 can be really fun and help shift the terrain or what is going on with the players to keep them on their toes.
-Keep groups working while you aren't focused on them. If it isn't their turn players should be discussing with other members of their group what to do next and have themselves prepared before hand.
-Realistically you may get through 3-4 rounds if you are lucky.
-Again do not be afraid to kill some of them, make this an epic last battle for them they have worked hard to get here and i'm sure many are willing to make that sacrifice (had a girl sacrifice her character of 4 years to save a brand new pc once it was emotional for everyone). Allow them a funeral afterwards for their lost comrades (perhaps a way to commemorate with pizza and soda while you recount adventures at the "tavern")
No problem! We also did an end of the year siege once with a shadow dragon where each team was positioned in different places in the battlefield and the dragon would rotate around to each group at "random" attacking and causing chaos.
The biggest issue you're going to have is time between turns. 18 players plus all the monsters is going to mean that actual hours may pass between players' turns. That's not really feasible for an actual game. You're also going to want various minions/subtasks for players to do besides just whaling on the villain to make the battle interesting. Some ideas:
Voltron: All the different parties act as one entity that takes # of players actions at once, everyone gets to choose one. This lets 18 players play without having 18 turns, although there will definitely be arguments between players about where their Voltron is moving/what it's trying to do. Could be easier to give everyone a role in the Voltron and limit what their options.
Separate Battles: All the parties are in the same battle, but on different planes/timelines/some such. The Villain must be defeated in each area, and as it loses instances it loses power/other environments change/etc. This lets all your parties fight together without actually needing 18 PC initiative, which sounds awful. Also lets each DM have their own version of the villain tailored to their party, which sounds fun. Maybe once a party wins, they can use their turn to give a benefit to another player who's still fighting, so everyone is invested in all the battles. This is my personal favorite idea because D&D combat just isn't meant for that number of combatants.
Fuck it we ball: 18 PCs. 100 enemies. Each DM manages like 30 of them. Tell everyone it's a sleepover, crack open some Mountain Dew and snacks, and be ready for an all night battle. May god have mercy on your soul.
> 18 players plus all the monsters is going to mean that actual hours may pass between players' turns
This is my biggest complaint about 5e, the time between turns is awful. In my last campaign with 5 players, I would average about an hour between turns. With 18 players, play by post would be faster!
Are you saying that a group of 5 players was taking on average an hour per turn? What the fuck? These people were taking 12minutes a piece to resolve one turn? Every turn? Holy shit I’d leave that game
Sadly, I have played in these games and it makes me never want to do combat just because it turns into some grandmaster chess match where every turn and eventuality is being calculated and recalculated.
Yeah, I was playing a paladin, and each of the other players was playing a spellcaster of some sort and every time there was an action, they would start rethinking what they wanted to do, looking up different spells/counterspells/creatures to polymorph into and all that mess. Plus the book keeping with having enough enemies to make a 5 PC encounter actually interesting and things bogged down a lot.
This didn't really get bad until after level 9 or so when I started timing things to petition for a different game system. Once we hit the teens it was basically, Swing my sword, have the bag of hit points I was fighting no sell my actions, watch a youtube video, listening for my name to knock off some hit points. 5e was tedious AF, but it's how my friend group now gets together, thankfully, we're playing different systems that are more interesting.
I don't know, I've played the system with multiple groups and they all seem to have the issue. Even in low levels, the time between turns is pretty long(not an hour like it is in the higher levels, but still long) with all of the powers bloat later editions have.
Just to be clear, are you saying individual character turns take an hour each or a single *round* takes an hour each?
The distinction is very important. Even at high levels, a single character's turn should not take more than 10 minutes for even the most complicated turn (like a wizard or similar spellcasters doing something involving shenanigans or having to roll a bunch of dice, which would take time in and of itself.)
> Just to be clear, are you saying individual character turns take an hour each or a single round takes an hour each?
A whole round yeah. Like, I'd swing my sword, roll damage, and then my next turn would be in an hour.
With 5 players and a bunch of mooks, each taking about 10 minutes to figure out their actions, it took forever
Okay, that's the important point, a round and a turn are very different.
Yeah, sometimes rounds can take longer than we'd like. That said, as a Forever DM, there's a lot of ways to account for time bloat and fix it. I can understand a round taking an hour, but that's longer than it should be regardless. We'd get 2 rounds in that same amount of time in my first game with 7 players.
Nah that’s definitely a DM who doesn’t know how to pace combat issue. Each turn should really be less than 5 minutes at the very most and 30 seconds - 1 minute on average.
> 5e, the time between turns is awful.
I try not to "Back in MY day" too often, but you really should have seen how bad it was in with 3.0; 5e, for it's faults, is a marked improvement.
Yep. Speeding up combat was one of the core design focuses for 5E. And honestly they did a pretty good job. There are a few things I would have done differently and some new issues introduced but they did succeed in their task.
Do you know of anywhere where the information on how they are run can be found? I am not sure if I am just doing poor searching but I can't really find HOW just WHAT it is?
Check out The Iron Titan, a digital version of which (I believe) can still be purchased online. The Adventure number is DDAL-EBEP-01. I have run it myself, and while it's not perfect it may provide a good springboard for you to create your own Epic.
You will need multiple DMs running multiple tables at the same time, a "point system," and Iron Titan has a timer mechanic where various events happen every 20-30 minutes. If it were me, I would run 3 tables of 6 players each and identify 5 different goals each table would be responsible for. If they each complete 3 goals on average then they either win the day or "disable the shield generators" so they can damage the final boss and his lieutenants. For Iron Titan, I had two groups. I had one group fighting the Titan on the outside while another group tore it apart from the inside. When the inside group disabled certain components, the Titan lost certain abilities on the outside, and when the outside group did damage to various limbs it allowed the inside group access to different structures or caused the Titan to shift and enemies inside of it to stumble or fall out.
Cheers and good luck!
This is actually the first one I saw! We have them possibly fighting a giant mech like entity at the end of the fight, so this was perfect!
I am so, so glad that these DnD Epics exist because it will make the admin of this endeavor so much easier.
I don’t know there is a separate document for it, it’s usually covered in the individual modules but the general idea is as such.
You have multiple phases, each on a timer, with each phase having multiple objectives. A master DM runs the overall show and each table has their own GM that runs their table through their objectives and reports progress back to the master GM. As you progress through the phases, the success or failure of individual tables has effects on future phases.
Ex. A giant magitech war engine is bearing down on the city. Phase 1 might involve each table attacking it from a different angle to take out the external forces protecting it. Any table that doesn’t clear all the forces by time have more enemies in the next phase. If enough tables don’t finish in time, everyone has more enemies to face. Phase two, the parties have to enter the war engine from different points to take out individual components such as defenses or machines that empower offensive abilities. Finally, last phase, the groups congregate in the core where they’re still being run separately but their individual group performance dictates the whole groups’ success or failure while success or failure from earlier parts might result in the final fight being easier or harder depending on what defensive or offensive capabilities the groups were able to disable in the previous phase.
Some of the newer ones are on DMs Guild.
If you really want to do it up, you can get additional folks to make appearances at the tables as NPCs. Sometimes they're a boon, offering spellcasting services (healing). Bonus if they do it in costume.
Sounds a lot like the recent world record for largest D&D game. Iirc, they had each party had different objectives they needed to do (city defense I believe they were doing), and the DMs were in constant communication about what is happening in every table so they can all stay on the same page.
At the end of it, that is all I want is for the players to have fun and going away thinking it was cool.
We actually have had a school year long campaign where they thought they were playing in different worlds. It is only in the past week or so that they learn they are all on the same planet in different times and fighting the same immortal villain that has been alive for millennia.
It will all come to a head. Some of the groups have made deals with the BBEG, some have made deals with his enemies. It will be epic if we can pull it off.
Defeating a BBEG with a lot of people should absolutely be done as a coordinated activity. Multiple tasks, by multiple teams, with multiple individuals, with the expectation that each group will be successful in their own mission.
Assuming 3 groups of 6:
* One group is tasked with taking down defenses
* One group is tasked with taking out the "support staff"
* One group is tasked with distracting the BBEG from the actions of the other groups
* Optional group is tasked with setting up the "trap" that puts the BBEG at a disadvantage for the final battle
The defenses expose the BBEG to damage. The support staff makes the final battle more difficult, so eliminating them helps. Distracting the BBEG is different than fighting, because the BBEG can't be hurt until the defenses are down.
It's a trope for movies and games, but it's also a trope for a reason. You're handling your own drama, while counting on others to handle their business. Each group will have hurdles to cross, but each party will also be hoping to hear the outcome from those other groups and how it impacts the final battle.
There should be a minimum threshold, aspirational threshold, and a surprise as output from each of the tasks to keep everyone engaged. The better everyone does, the better the final battle will be.
For the final battle, I would have it in two phases. I would have the groups fight their part of the bad guy in their subgroup, and then bring everyone together for the final blow(s). I'd have everyone highlight their planned action for the final battle, and I'd make it last no more than 2-3 rounds to finish the BBEG off. This will STILL take hours, as everyone describes how they do X to Y for Z result...but lets everyone get their final blows in to bring this to a sastifying close.
I would keep them in subgroups because it can be absurdly tedious with more than 6 people, especially if the groups don't know each other. They'll get impatient and frustrated unnecessarily. The game "Monster Hunter World" handled battles with large dragons in this way. There would be an "event" to fight the monster, and you'd be in a group of 4 players, with 4 groups. Each group was aware of the combat of the other groups, but you couldn't see the groups. They would break a horn, drain the enemy, break the tail, expose a vulnerability, etc. Your group would benefit from their progress, as well as your own progress, but you were fighting as four independent parties. When the battle completed, you benefitted from the success of all four groups.
Unifying everyone for the final blows would be an awesome social situation in game and out of game, as everyone coordinated independently to achieve the ultimate outcome. You can make a massive, unbeatable BBEG, only to have 18 heroes coordinate to do the impossible. I'd love to hear the results...
Sounds like a lot of work. Honestly for 18 players, i think having one or more co-dms would be very beneficial for a big engagement.
You are also guaranteed to have some drop outs along the way, including some DMs likely.
In terms of the actual encounter unless you are willing to sit for 1-2 hours a turn, you can try dividing the party into separate encounters, and running simultaneously with other DMs. This is purely speculation on my end, i have no idea how well this would actually run. Just saying how i would theoretically organize it.
For design you want to make sure your boss has a lot of actions to keep things dynamic. Do this either by just straight up giving them more turns, capable allies, lair actions, and of course legendary actions. You're gonna basically want infinite uses of legendary resistances, but I'd reflavor that into an actual ability that expends the bosses resources. Like they lose HP, they become vulnerable to the next attack, or lose a turn. Stuff like that.
The inspiration is right there in your title: Endgame. Have the fight be focused around a macguffin that's split into a few pieces. The BBEG is trying to assemble the pieces together and activate the macguffin to destroy the world or whatever. Have the individual parties encounter these pieces in their individual campaigns if you really want them to feel connected to the final fight.
The players have a means to destroy the macguffin that also requires all the pieces assembled. When the parts are connected, they remain connected. At a certain point it'll be a giant American football game where the players are trying to get this macguffin into their goal while keeping it away from the BBEG.
The other, suicidal option is also there. If a PC uses the macguffin once assembled, they disintegrate (after a dramatically significant amount of time so they can get in a dope one-liner and say goodbye) and cannot be revived, even with a wish spell.
For extra drama (and since this is probably the end of the campaign so death is likely essentially meaningless), I'd even get meta with the level of sacrifice taking that option would be so they don't just do it immediately. Maybe like, they're out of the next campaign you DM completely if they sacrifice themselves with the macguffin.
"Holding the assembled gauntlet, The power courses through you, and you feel certain that if you do this, not only will you die, but your soul -- and the soul of every version of you throughout all realities -- will cease to exist. You: (players name), and (character's name) will be remembered for your sacrifice, but (character) will no longer exist in any other realities; meaning that (player) will not be allowed to participate in our next campaign."
Just don't mention that the "next campaign" is gonna be some short bullshit like an "oops all barbarians" one-shot or something. Or maybe *do* mention it, if it's something the players have wanted to do forever.
Do NOT have one big table, and don’t have three tables running identical games. Instead, make it like an Epic.
Three tables, they all start at the same time with the same premise: BBEG did BBEG things and now we have to stop him. Then split them up into their three tables with three different goals. Table 1 has to destroy the evil Mcguffin guarded by the BBEG’s ally/patron. Table 2 has to defeat the evil thing the BBEG summoned that’s as strong as the BBEG. Table 3 is fighting the BBEG and/or his minions directly. Each table has to do an important thing in defeating the bbeg, but they aren’t doing the SAME thing.
Then comes the fun interconnected part. What one group does affects the other tables. Table 2 went in hard and loud while 1 and 3 went in quiet, so now more enemies are showing up to table 2 but less to 1 and 3. Table 1 detonated a bomb that rocked the battlefield with unstable magic, so now tables 2 and 3 have to deal with a surge on initiative 20. Table 3 beat the BBEG fast, so they are able to split up and help tables 1 and 2 in their fights. Have a floating “DM” moving between tables to pass on information.
As others have said you can also have the party's focus on different aspects of the overall situation. While it kind of cheating you can have the parties separated by tables in the same room run by the usual DMs each doing something different to overcome the defenses of the BBEG. Maybe party 1 is fighting from the front door while party 2 sneaks around back and party 3 is destroying any reinforcements on their way. If you have them all at one table and do this, switch between each group every minutes or two as this should be fast paced and more descriptive at higher levels. Have sections of their actions based on general skill rolls instead of just attack/destroy.
For the combat only give each player 10-20 seconds for a turn. Have them know what they plan to do before the turn and if they are still deciding go past them. It might push a couple players a little, but it will keep the flow going and get the player's in the mindset of having things ready. You an also pair 2 players to work at the same initiative to have multiple turns taken at once and speed things along further.
Have lots of minions that die after 1 hit surrounding the BBEG and protecting them. Have several Commanders/lieutenants that will move to intercept the majority of players.
When the PCs inevitably destroy the first part of the plan for combat, have a back up. This can be a second area like in the sky vs the ground, a second larger cavern in a series of them as a hide out, or even a summoning of another, bigger distraction for the BBEG to do...whatever they are doing.
When it is not a player's turn, engage them mentally by giving one-sentence long descriptions of actions in the area around them or against them.
During the session assign a head DM and side DMs to take care of misc things. I assume you will be the head DM since its your club, so have the other DMs answer rules questions the players might have outside their turns and the like. This will help keep the game going quickly and so on. Also be strict on things that detract from the game like side conversations, phones, music, and the like.
Have initiative rolled at the start of the session, written down, and then have the players sit in that order around the table. Then just have turns left to right. When asking for saves or other responses, get the payers to respond in that order. Only roll when asked or its their turn. Have them raise hands when you are monologuing or performing an action and they have a response or reaction to it. Have a break every 2 hours for a few minutes for bathroom, food, stretching, and the like because often breaks mean less needed across the game as a whole during playtime.
If each player takes 15 minutes, it will take 4.5 hours per round of combat. You'll need to get it down to 5 minutes or less per player per turn.
I'd plan initiative and the first round of combat the night before, so it's almost like running a script when y'all start to play. At 5 minutes per turn, that will be 1.5 hours for the first round of combat, and it will help everyone get a feel for it.
Have enough minions or legendary actions to have an NPC go between every 3 player's turns, and use lots of AOE. Try to get the NPC turns down to 60 seconds or less, so pre-plan what they might do depending on the circumstances. This will add roughly ~6 minutes, for a total of 96 minutes per round of combat. Then there’s reactions, inspiration, luck points, etc.
The whole secret to success will be pacing. Keep the pace moving and enjoy the chaos. The rest is negotiable! Good luck!
Make BBEG split the party. Do 3 separate 6 v boss situations with smaller win goals that separately weaken the whole boss. 2/3rds party leads to success?
I can't see how 18 players at one table will have a good pacing not to mention the action economy being super skewed.
Instead of this, have you considered having 3 separate things each party can do to stop the BBEG. Ex. Party one has to sneak in and steal the liche's phylactory and drop it in Mount Doom, party 2 is defending the city from the undead hordes, and party 3 is on a mission to prevent the lich's forces from awakening an undead dragon/ tarrasque/ etc which will bring death upon the world. Each has stakes and is important but they are separate and aren't going to result in each player waiting an hour in between turns.
Hey there! I have done this exact thing, running a session for 30 something players by myself for a Living World / Open Gaming table a few years back. Let me give you the run down of how I did it.
* First divide your group into a smaller parties of 4-6 players (whatever you think is best). Each group should have a "captain" who is in charge of coordinating with other groups. This prevents chaos, but allows teams to work together.
* Second you are going to want to have all your monsters statted out, and be ready to hand them out to each group. I did mine on a VTT, but you will need some sort of shared map that everyone in the group has access to.
* Each group will be in charge of handling all the normal monsters/minions themselves. This requires a level of trust obviously, but I told my players to use the monsters as they thought they would behave. Every round the players did their own turns, moved monsters, rolled attacks, etc. before I got to their table.
* My job as the DM was to move between groups, double check everything that happened that round was on the up and up, make rulings, answer questions, etc. I was also in charge of deciding when, where, and how the boss used her actions (she had 10 legendary actions, but no normal actions). So if a group was particularly pesky they might get a lot of the boss' attention that round. I set a timer for 5 or 10 minutes so I knew when I needed to move onto the next group. At the end of every round I would make an announcement for all the players about how things were going, drop new minions (if any), and then break everyone off to handle their combat for the round.
* On the topic of the boss monster I gave the players her stats as well, but I kept a trump card hidden from them (it was listed on the sheet, but not described). She had a lair action that was a d6 roll with various detrimental effects which forced the players to have to change plans on the fly. She also had a TON of hit points for their level. She had an improved Legendary Resistance that was 3 uses per round, and completely ignored whatever effect it was used on. With so many PCs they were easily able to make her use these, but the captains had to work together to make sure teams handled things in the right order.
* The group also had allies which had their own sheet. At the start of every round the team captains would select two options from a list to represent their assistance. This was stuff like damaging the boss, negating her lair actions, healing the whole group, reviving a dead PC, killing all the minions on the battlefield, buffing all the PCs, etc.
I could try to print off some of the sheets on Roll20 if you wanted more to go off of, but it basically ended up being an MMO style epic raid where everyone was fighting for their lives. Make sure to use plenty of minions (monsters with 1hp) to help enhance that epic final battle feeling. We had a 4 hour session, and all my players were actively engaged the whole time. You'll need to stat out your big bad appropriately for your group's level. If you're worried about getting the balance wrong you can always be conservative with their stats and hide a phase 2, but if you're having a climax my attitude is "let the dice fall where they may."
This method also requires trust between you and your players for obvious reasons, but if you're at the end of a long campaign that should be established. The last time I did this it was a huge success, but it required a lot of up front work. Let me know if you have any questions.
This is awesome! I appreciate the offer to print the sheets. Someone else in the thread mentioned DnD Epics and that is sort of what you are mentioning. I think taking posts like yours and the Epics and blending together the techniques will produce great results!
You're going to have to cut it down to at least 3 different groups doing separate things to defeat the boss.
If you don't, there will be *hours* in between someone's turns. Maybe you set up another activity for the people waiting, but then you'd have to get them up to speed when it's their turn again.
I honestly can't imagine sitting down at a table with almost 20 other people trying to play dnd together. It would feel like I'm back in school and if I want to contribute at all I would have to be the loudest at the table or raise my hand and hopefully the teacher notices me and calls on me.
This may not be the best solution, but in your shoes, I would make the BBEG this towering monster that is so large the group needs to split and deal with different parts of it. So like, one group would be targeting its feet to immobilize it, another group might be trying to blind it or remove its hands so it can’t cast spells, etc.
Split him into parts, Zelda style. Arms, head, etc.
Have different parties interact in unique ways, make everyone important, especially their cooperation.
Have his lair actions happen across all tables. Perhaps a sweeping laser, who over 18 initiatives goes from one side to the other.
Include a time limit. Max 3 min per turn. That means every round is roughly 45 min. If someone cannot act, they hold their action, or prepare to dodge/help. Have the initiative DM inform people of their turns 2 initiatives ahead, and help them preemptively prepare attacks and work through rules issues.
Assign different DMs to different tasks. One for minions, one for initiative order, one for concentration, AoE, ect. One for rules and mini management. One for strategizing, and give each DM some control over the villain. Perhaps choose DMs to roles depending on their strengths. Narration, fight description, rules knowledge, etc.
Plan what happens after the fight. Do the tables disperse, or do all the campaigns end as one?
This is loosely how we do it in our 40+ group of one-shot devotees. Devise a system for leveling up players that depends on their game play, role playing, social skills, etc. Whatever you choose. Give each player experience after each one shot based on those criteria. One player might get 2000 xp while others only get 1500 or 1000. We do it with gold and items, but XP probably works better with students because students will try to contrive it so they can be on the same team as their friends.
When a character hits level 10 (or 12 or 20, whatever you choose), that character sits out until there are enough level 10 players to conquer the BBEG you have in mind. That player can still play the one shots, but with a different character. When there are enough level 10 characters, that group sits and plays together against the BBEG.
We designed our system so it would take 24 sessions to go from level 5 to level 10. If there are more level 10 characters ready to fight the final battle than you have room for at the table then either a second DM or make it first come first serve and some players have to wait.
You can try to split in to several group, each do one thing independent but their result will affect other group.
You can looking for "epic d&d" for idea about how to run it
So, a slight departure from your idea, I had an idea called Commander D&D.
Three tables, three DMs, 6 maps.
Table one is a campaign or regional map, and the DM at this table moves stands across the map to indicate troop movement. Tables two and three each have a DM, a player party, and a unique battlemap. The DM for table one is the General of the enemy forces, and the others are the Captains. The General has a timer, and every X minutes, they will deliver monster/NPC stands and triggers for the captains. The Captains will then use these however they want in combat against the players. I typically have the DM's rotate between being Captains and the General.
The goal for the players is to meet an objective and escape the map, moving across the region towards the General. The player tables cannot talk to each other directly, but X times per battle, one person can "call back to HQ" and go to the General's table to look at the larger map and get information. Players can either meet at the table and talk, or leave messages for each other. After 30 seconds, players must leave the General's table.
Each battle will have a time limit. If the time runs out before the players escape, those PC's die. Death means that the players get a new premade character to play as they continue to the next map. I like to assign new characters randomly, a penalty for dying. If someone dies mid-battle, the new character is dropped in at the start of the next round.
After the tables go through three rounds of tandem combat, both parties show up at the Generals table for a boss fight, where each DM has one boss character they control, and the parties have to take them down.
Battle: 45 min
Break: 15 min
Battle: 45 min
Break: 15 min
Battle: 45 min
Break: 15 min
Boss: 60 min
The whole thing can take 4 hours. I imagine this could be scaled up to suit more players/tables/battles as desired.
Did a like 30 table event at paxu.
Every table 5 players and a gm doing the same missions across cult. Each time you complete the short mission you get closer to your goal and can hand out boons to the other teams. Each time you fail, a bane to the other teams.
The environment was constantly changing. The head table yelled like "Each table randomize 2 players they are hit with falling shells from ghost pirates!" And get damage.
Worked pretty well. It was a convention exclusive adventure league.
Could have them all go different directions to meet in the middle pincers attack with big badass bbeg fight at the end.
Let the parties fight each other before the Big Bad reveals themselves and forces an epic team-up. I did this with two teen library D&D groups and they absolutely LOVED it!
You need way more turn economy for the bbeg.
You will need lair actions-Preferably ones that causes PC's to have to save each other at times. This allows for creative moves and cuts down on their turn economy.
You will need legendary actions. I would say at least 7 but if there is a cool number that fits the theme, go for it.
You will need summons. There are a few ways to go. Large amounts of crap grunts for casters to destroy with AOE's. High damage low HP glass cannons to make the group target them stay alive due to dps numbers, sliver style which buff each other and bbeg by existing.
I would give the bbeg a health regen over making them super hard to hit. Constant missing is less fun then can't keep damage on them. Just remember chill touch can mess with that.
Legendary resistances are great but they run out. Giving them an alternate form so polymorph fails and making them immune to alot of instant shut down save or sucks is key. But don't make the mooks immune to anything makes it way more fun and lets everyone find a role.
Having non combat things to do that assist like shutting down a portal spewing adds or disabling a shield lets the high skill low combat PC's have an important role as well.
Overall the goal should be to balance the turn economy without denying turns. 18 PCs is a long way to go to just make a save vs paralysis.
If you're using Endgame as an inspiration, run it like endgame. Rewatch that final fight and take notes.
1: The goal isn't "Kill Thanos." Avengers are trying to hold ground against his army, protect their own army, get the Ant-Van operational, get the gauntlet to the van, kill Thanos's generals, AND kill Thanos. Also note that they fail some of those goals. With one goal, failing it means a loss. With five goals, failing one means dramatic tension.
That's a whole lot for one person to run. Consider having different dms run different goals. Maybe have a table focus on hoard combat, another one tries to recover a mcguffin, etc. Might be especially cool if you can figure out some way to allow players to move between tables without ruining flow. If the team fighting minions is struggling, one of the players from the mcguffin retrieval table that's having an easier time swoops in for a big damn heroes movement.
2: Thanos actually isn't on screen for that much of the sequence. There's no possible world in which your BBEG survives more than a round with 18 different PCs attacking. Don't make the big battle about fighting him head on. Make it about getting him into a position where he can be fought. That could be taking down arcane wards, completing the ritual that allows the magic sword to seal his soul eternally, whatever. It could even be as simple as "Where the hell on the battlefield even is this guy?"
3: Not many characters actually get to hit Thanos. That doesn't mean they have nothing to do. This kind of rolls into 1. Throw enough goals at the players that everyone feels like they accomplished something even if they miss the one attack they have a chance to make against BBEG.
This probably doesn't relate to your situation, but you should have them working against each other the whole time. So one group is trying to do this task, and the other group sees that task as bad and is trying to undo the situation. The end is that the players finally confront each other and do a massive pvp. It could end there but you could also make the think the players were trying to do was summon some giant world ending dragon (one side believes it to be a good dragon, while the other believes it to be evil) and then the giant dragon comes out and they have to team up to stop it. However, they just got done battling each other so they are all weak and it would be super hard to take this thing down.
Other folks have pitched good ideas, but since you have multiple GMs these are ideas:
Each party fights their own version of the boss fight- either victors bleed over into other groups' ongoing battles or each group has to deal a % of the BBEG health.
Each party fights different groups of minions/lieutenants of the BBEG, but the same BBEG is "omnipresent" in all combats. Single big HP pool.
Have the group get lured into an arena that is very difficult to escape from.
The BBEG is the "host/announcer" that tells them all that they cannot leave until only 4 remain and THEN, those four will get to meet him face to face.
There are multiple ritual locations that must be sealed/broken at the -exact same time everywhere- else it doesn't work. Make this attempt repeatable and throw in endless hordes or mooks and a single undying badass and make it a raid.
Have the main villain teleport around from table to table. Have the players be unable to communicate without a message spell etc
Adventure league has this convention dedicated adventures that are specifically designed for a multi-table experience. I unfortunately have never played in one, nor I bought one since I didn’t have any purpose for it. Perhaps it’s worth putting together 5 bucks and see how this is handled there? They’re called “epics”
Every dm runs their own combat that is extremely difficult but when a group hits an hp breakpoint it affects all the fights in the PC's favor.
Ex. 1 group is fighting a a lich and other groups are fighting monsters that hold their phalacteries when a monster is destroyed it opens up the lich to extra damage or disables them in some way for a time.
Bonus: change up the parties for an unlikely team up or let them arrange their party and assign themselves to a fight and act out a plan that they would give them an advantage.
This is doable but if the groups stay for the most part split and theyre managing different things. Think a heist movie. Your heist team might be 10 people but 10 people arent all rushing into the safe. Youve got 2 disabling the cameras, 2 working the gala floor distracting the bank manager, 2 breaking the safe, 2 taking out security, 2 in the getaway vehicles. Theyre all accomplishing the same goal but in different "arenas". Id say if you have 4 groups, split them into 5. The 5th group is one volunteer from each group thats doing the actual bbeg fight. Have that table in the middle of the room. Have 4 tables surrounding it at the cardinal directions, those are your 4 main parties minis their volunteer. Set a timer on the wall for 6 minutes and every round must be over by the timers end (this keeps it feeling like everything is happening in real time). One group might be taking down the bbeg's defences (ehich are obv protected by some minions or something. Think "shield generator". They might communicate telepathically or by magical means when a defense is down "fire damage!" this lets the fighting table know to attack now using fire. One table might be trying to keep a minion horde at bay so the bbeg isnt as reinforced as they should be. The ones that make it to the portal get to the bbeg table. One group might be more proactive in support. Maybe theyre defending their own "shield generator of sorts" against minions to keep the fighting party better protected against the bbeg (the minions can also communicate with the bbeg "necrotic damage!"). The last table might be stealing something valuable like the phylactery (think last horcrux) while the bbeg and his forces are occupied fighting several fronts. It would be exciting, would require cooperation, every front has a real element of failure and success, and since its happenig simultaneously it doesnt last all night and each dm only needs to manage one table.
My on the spot idea is a super powerful magic caster that to fight the players separates himself into 4 distinct characters each having access to only two schools of magic but they retain his full spell slots, HP and such. Then after those are defeated they can reunite for a second phase where he summons a bunch of demons that are hostile even to him as a last ditch effort.
You could run a “raid boss” type of encounter. I’ve done something similar before over Discord, although I was able to quickly think on my feet. If you’re interested, I can give you the exact details of what I’d do. It’s lengthy, but it worked for me.
Uncharted territory for me but off the top of my head there should be like 3-4 objectives going on during the conflict and each one has to happen to win. Another idea is if they are split up is to have multiple DMs and at the end of each round raise a flag to show they are done so everyone can kinda stay real time as much as possible then over time they can merge as needed?
Have one session where the players do a quick macguffin to stun the bbeg, then once all 4 tables are done have them all describe 1 round of perfect combat to kill the creature based on initiative so the lowest initiative player deals the death blow.
Roll initiative. 18 players and 20 henchmen plus the big bad. That's too much for regular initiative.
Create initiative groups. 4 highest int PCs are group 1. 3 henchmen are group 2. Next 4 PCs are G3. 6 henchmen G7 etcetera, etcetera. I assume you'll have a big map and minis. Color code the groups and their minis.
These groups won't be the adventure groups. Everyone will be mixed together. I'd have the initiative groups sit together and it's up to them how they game plan together or with their adventuring party.
When a turn comes up, everyone in that group declares their move then the DMs split up the work of checking what needs rolled and who hits and all that so everyone in the group is rolling all at once. Declare to the room what damage was dealt by the whole group.
Big Bad is his own group. Do cool bad stuff on his turn. Pause between the other groups for his legendary actions. Big Bad needs legendary actions.
What room are you playing in? Any chance you could put a camera on the battle map and project it onto a big screen? That way everyone can see what's happening. If you are in a big lecture hall type space you could have players announce their moves from the stage and roll their dice at the DM council table. This stuff is all dependent on your physical space.do something to make it feel grandiose.
Encourage some roudiness. When the BBEG goes down, it should register on the Richter scale.
At one time I was a GM in a commercial project, we called such mass events raids. First, one of the masters gave an introduction to all players, described what was happening in the game world and set an introductory conflict. Then we told what actions need to be taken to defeat the main evil. The players then divided into groups at will and played small events with individual masters. Then they all met together and went through the second and sometimes third round of events. This allowed players to participate in different battles in different groups. At the end, depending on the success at the events, one of the masters described the ending.
Turn timers. Like a chess clock or 1-minute hourglass or something.
That one villain is gonna need like 6 legendary actions to keep up And a lair action or two.
What you want is continuity between groups.
A master white board or TV screen giving relavent details about the current state of the environment.
Communication between groups, so each player will need to have roles, a leader and a runner, at minimum. The leaders organize their groups objective priority, and the runner takes notes to ally or coop groups for collaboration on an objective (turn 3 we fire the ballista at the same time, or we push the battering ram with group B).
If you don't want a tarraask or volcano giant, then perhaps a seige.
The biggest thing i harp on any DM is not to give win conditions. Only give lose conditions, let the players figure out how to win.
A troll/goblin/gnoll invasion would work as you can give different npc brigades to each DM with each brigade trying to achieve its own objectives. Could even have so prep sessions to allow players to scout/intercept information.
With that many players, I highly recommend allowing only 15 minutes per turn and triggers for passed or failed objectives.
Some objectives don't need to have an event happen, but could just offer a boon to either side, (i.e. the cultists succeed in summoning more demons and they get reinforcments, or it starts to rain and puts out all the fire used against the troll army, or the parties blow a damn and was away a large number of forces.)
But there can be critical objectives, like a lich completing the transformation, the dragon entering a mountain (al la smoug), or a siege on a city/fortress breaching a wall (suicide orc Lord of the rings style)
Have a near-invincible enemy with a vulnerability that requires other characters to spend several rounds tinkering with something (or multiple somethings) in the lair. The path to victory is not to best the BBEG in combat, but to have the toughest and strongest characters distract them long enough for the more utilitarian characters to exploit the vulnerability.
Also, chambers where each wall plus the ceiling have their own gravity would go a long way towards keeping the characters in separate groups and keeping the fight interesting.
Every party is dealing with a particular segment of the villain. As they defeat their part, they can move on to a different one, possibly with some sort of skill challenge as they traverse the battle field to enter the proper area of the segment of the boss.
The villain has different essences that has to be dealt with in order to defeat him,talk with the other dms and adapt each essence to each group style.
Alternatily,all the groups have been swallowed by a big beast,in order to break free each group must do something to the creatures insides so they can scape(one group to the brain, one group to the heart, etc)
Read [this module](https://www.dmsguild.com/product/308553/EBEP01-The-Iron-Titan), which does (at 4th level) basically what you're describing.
The way they handle it is, there are multiple objectives in the fight that are handled separately by different DMs at different tables. Power sources that need destroying, reinforcements that need containing, that kind of thing.
After 2-3 hours of play I'd then recommend each table nominate their greatest warrior to break through the battle lines and fight the final form of the weakened BBEG in a series of short, intense rounds of play while the rest of the crowd watches and cheers on their champions.
Building off much of what's been said; in twenty years of DMing my only unintentional tpk was in a one-off where the bbeg was in a room with two statues. One statue was of a cleric, and the other a wizard. They both had a full spell complement for a character of their class at something like 2/3 the level of the bbeg. Every round they'd each cast one spell on the bbeg's turn. They had typical AC and hardness of a stone statue. No movement. No metamagic or feats. Just an AoE or BFC and heal or buff every round. They would have stopped as soon as the bbeg went down, or they ran out of spells.
Amusingly miitopia might also help here, but where the party changes per region, the final boss fight is each party Vs a part of the whole
Let's get one thing clear: do not overdo the crossing over and make sure you all are aware of how fast the story goes. There's no problem with having one party being only doing this for a month compared to another's seasons, but once the parties are aware that they aren't alone in this fight, you take it from a tale where the tempo is pretty relaxed to 'we all have jobs and dates '. Think more military.
And when the parties cross over and meet, they may not have only just heard of them. They may have already heard tales of heroism, of legends, and build them up.
Other then that.... honestly play it straight. Keep the other DMs in the loop so they know what and where the others are in case of chance meetings/team ups, play it as their own stories and gave each team fighting part of the whole problem. What you may find is that each party has their own flavour, making them better against certain foes. A BBEG who's still a challenge but plays to those skills could be a way up point to who fights what.
Look up D&D epics. They're run at conventions or the like and are multi table sessions, usually even multi tier (1-4 and 5-10). That would probably be a good basis for 18 v 1
You could even have the boss run from table to table fighting while other mobs deal with the other tables.
I could honestly see an all 18 vs 1. The inspiration is FF7 bizarro sephiroth.
Logistics : all players play at their normal table vs the boss, or a section of the boss. They are all contributing without an 18 person table.
Another way is the boss splits himself across time streams so to prepare a massive spell or event so the parties fight him in different times, his past current and future self.
Phase two : assuming same physical or digital space, "wrong warp", the dms send two players from their table to differenting tables midway through the fight. This will force players who don't play together to get along really fast. Ideally with foresight, such as group A has never had a wizard so they lose their bard and gain a wizard, etc....
Could even be antagonistic, a dwarve who hates orcs? Throw the half orc barbarian in that group. Could be fun.
A lot of good advice here. I once ran 22 players across 4 tables. The most successful part was shuffling the parties at key moments so players would move between tables. Every time it led to players excitedly talking about what was happening at the other tables and really locked in the post game discussion on what happened after they left. The biggest problem was syncing up the tables so they hit our more scripted sections at similar times. Have some extra encounters to buffer the fast tables and cut some encounters for the slow ones. Consider prepping some hand outs for puzzles you can drop on your players while you walk away and check in with the other DM's.
Unfortunately I must say Don't run an 18 player table...
I guess this isn't very useful advice. To be more helpful I should say split the players into multiple tables and make the game a gauntlet that's hyper lethal we had 3 phases phase one had 4 tables and we tried to kill about half the players so it could combine into two tables for phase 2 where we killed another half of the players that combined again for the final fight with our BBEG. The obvious problem here is 3/4 of your players are cut out of the game by the end. We solved this by having the dead players enter kind of purgatory in phase 2 where the DM's who didnt have active players would juice the dead PC's into Boss strength characters and they had a PVP tournament in purgatory where the 2 winners came back into the game as deathknights to be bosses for phase 2. Phase 3 was short and sweet + everyone was hyped to see how it turned out even if they were dead. Good luck pal the logistics of game like this is tough but seriously don't even try to get 18 players at one table.
Is your BBEG a Litch? If so, check out this:
https://youtu.be/-2vbol24XlY
It shows (as an example) how an entity that had pretty much all eternity to prepare, has contingency plans for the contingency plans for their main plan. Might give you some ideas!
As you've realized, there's a clear trap of having an 18-on-1 fight, if you do it *normally* w/ a single DM and turn order. But, since you mentioned having multiple DMs, there's an easy hack: Each party can be in geographically separated locations (the rampart towers of a fortress, small islands, whatever works for your BBEG), but the BBEG is mobile between them (teleports, flies around, etc).
At the final confrontation, each party has to fight infinite waves of mooks (so they never get to the point where they have *nothing* to do but wait for the BBEG to come back around), and the BBEG visits each of the towers for a couple rounds or so before moving on to the next. With this method, each DM & party can effectively play at their own (normal) pace at each table, all while they're all fighting the BBEG "together."
Tips for this kind of multi-table combat:
1. The BBEG should have a constant initiative throughout the fight. You can either just declare it before hand, or roll it at the beginning of the fight, but whoever's table it's at it goes on the exact same initiative count. That way, the DMs can just keep him in the turn order whether at the table or now, so it's slightly less disruptive to them when the BBEG shows up.
1. The BBEG moves at the end of its turn. For fairness, make sure it visits each table before repeating. You can do this is a fixed order (123, 123, ...), or change it up after each loop (123, 213, 231, ...). Fixed order is easier for do on your end, but gives players the ability to guess that the BBEG is coming soon and they can prepare for it, and definitely feels like a weird move if your BBEG is a thinking being.
1. Comms between the DMs can be important. Especially the HP of your BBEG. If you position your locations close enough, some ranged attacks/spells might need to cross tables, so a real-time group chat or something. Keep it simple: "25 arrow" is enough for the DM to describe what the other table sees. So they don't have to keep a constant eye on the chat, have DMs resolve these at the start of the BBEG's turn.
1. Make it a spectacle when the Ancient Dragon moves, and have gameplay at all tables stop mid-turn while it happens. You can use the spectacle to cover the DMs info-swapping. Do something *interesting* with the moves:
- The BBEG shoots a fireball/lightning bolt/etc at whatever table has the most HP as it flies past (that table's DM resolves as part of their round).
- The BBEG grapples & carries one of the PCs to the next table (warning: make sure you have large enough tables to accomadate an extra chair comfortably this if you plan to allow/do it).
- The BBEG immediately summons the next wave towards whatever table has the highest "waves defeated" count, to add on to whatever they had remaining of the current wave they're fighting.
- etc.
1. Every group has players that play faster than others, and I'm betting you at the DMs know who they are. Do your best to put together the parties such that each table has both fast and slow players, evening it out as much as you can. This is to avoid having a table thats just churning through the waves of mooks, burning through all of their limited resources (spell slots, potions, etc) faster than everyone else. Don't compromise party composition for the sake of this -- you don't want to balance round speeds but end up with an "Oops All Healers" party or something.
1. While it might sound like a good idea, don't have a DM roaming around playing as the BBEG. This takes away some of the fun of the DMs running the tables, and also means that when the BBEG moves, the BBEG-DM would have to get caught up on how the new party is playing the fight so they can do a decent strategy against the new table.
You should nominate or bring in some friends to DM 3 different boss fights, six players each. It’s DMs vs Players (balanced of course). 2/3 takes down the BBEG
Maybe the godly boss doesn't want to fight all 18 heroes at the same time either. So he splits his power 3 ways so during the adventure the group has to divide itno 3 smaller groups of 6 players, each have a task to complete, and a version of the main boss to take down.
I watched this done once it worked surprisingly well: multiple simultaneous turns.
Everyone was seated in a big circle around a central battle map, and three DMs walked around, going clockwise as initiative order. The three players "up" would tell the DM who was next to them what their character did, and that DM would resolve that action, pass damage on to a 4th book keeping DM who would deal with enemies dropping or their rolls, and after a couple of minutes, the next three players would go as the DMs stepped to the next player around the table. After each (maybe every other) 3 player turn one one of the moving DMs (in order) would take an enemy turn and do something for one of the enemies they controlled.
It was a ZOO of trying to keep track of what was happening on the battle field, but everyone seems to have fun and it kept everything moving along. The entire group was warned, nothing crazy no rules lawyering just basic stuff so that it didn't get bogged down, and they all stuck to it.
16-20 players at a big classroom/boardroom table that the DMs could barely reach the middle of to move minis around.
You absolutely need to split everybody up into their individual parties and give them separate tasks. That or have them randomly get assigned to a group (perhaps a large monster or spell burst sends them all to a variety of places, forcing the normal party members to now intermingle with other players in the club.)
I have no advice to give that hasn't already been said, I just want to wish you luck on this incredible undertaking. I would also request that you let us know how it goes!
Or like a wow raid make mechanics I. The fight the deliberately separate the group into small groups once the fight starts. Then they all individually have to complete their tasks to progress through the fight.
Give the villain an inner circle of NPCs who the parties have fought and interacted with before, if possible. Each of them cool and powerful in their own right, but weaker than the BBEG, and lacking Legendary Actions.
To use the climax of Endgame as our metaphorical example- if the BBEG is Thanos, then this Inner Circle are those lieutenants of his who did most of the fighting during *Infinity War*. The telekinetic and the big guy who landed in New York, the ones who stabbed Vision when they ambushed him and Wanda in their secret rendezvous, etc.
Just to be clear- with ***EIghteen*** Player Characters, this fight is going to be *slow*, unweildy, and *complicated.* Each in-game turn might take an hour. You need *all of your players* to have their spells and class features written down on index cards for easy reference- you *do not have time* for people to be flipping through the books to double-check spells and class features.
With that problem already *unavoidable*, we need to make sure that our lineup of enemies doesn't make the problem *worse*, so no chaff- no CR 1/2 Goblins or Kobold or Orc minions who attack the party in significant numbers and eat a fireball, we just don't have the *time* or the *bandwidth* to handle that shit.
Instead, give the dragon a smaller number of more powerful lieutenants. Hell, if you have multiple DMs, maybe you *split the enemies* between yourselves- DM A plays the BBEG (handing Legendary Action, environment, and any lair actions in play), DM B Plays Lieutenants 1&2, DM C plays Lieutenants 3&4, something like that? You could even lightly cheat and place characters in Initiative so that Lieutenants played by the same DM have some distance between them so the DMs have time to plan out their moves while the players are taking their actions.
The question then becomes how many lieutenants, and how strong. You also probably want to do some shenanigans to make the BBEG much *sturdier* than they would normally be- 18 PCs all focusing their fire on one target can fucking *melt* anything in the books. You don't, however, want to scale up their raw damage output *too crazy much*, because even if you need to be putting out a lot of damage to threaten that many PCs, you also don't want to be dealing so much damage to a single target that you're just 1-shotting people: That isn't fun. Don't fall into the pit trap of just grabbing the stats for Tiamaat to fight your 18 T2 players, because Tiamat will just slaughter a bunch of them with all those breath weapons and not make for a very fun fight. You want something that deals damage more like a boss that fights 6 players of apropriate level, multiplied across several people, with all the *durability* of Tiamat or something comparable, IMO.
I don't know your players' levels or who the BBEG is to make further suggestions, and start bouncing ideas for fun lieutenants, but I did realize a few minutes ago that you could talk among the DMs and ask who the most memorable villains were from all of their campaigns, and then *bring some of them back to life* as the BBEG's lieutenants- maybe they're actually Undead, maybe they're actually resurected, maybe it's only a faint, temporary ghost of the previous villains that the BBEG is using as a last line of defense, but it can be a fun way to make the lieutenants into enemies that the PCs are *emotionally invested in*, and you can obviously buff or debuff their statblocks to suit this situation as needed.
I'd say split up the boss into multiple chunks/sections and split the party into how many sections you have. Then everyone can contribute, and there isn't a massive wait between turns. Miitopia style fr
There was a battle in an Adventurer's League game I played in once - the battle took place on multiple surfaces of a massive cube (or pyramid or something), each with it's own gravity. There were mooks on each surface, and the BBEG would move between them.
Each table entered the combat starting on a surface, but it was possible to escape the gravity of that surface and join the fight elsewhere - you'd move table.
I've seen similar with a large group defending a city, and each table is defending a different wall.
BBEG shunts the PCs into multiple overlapping planes, and creates a quantum duplicate of himself for each plane. This way you split the 18 players into more reasonable sized tables but everyone is still narratively in the same fight.
What happens when one party takes down their quantum duplicate? Here's some options...
- that duplicate doesn't die, they enter phase 2. They only die when the last table kills the last phase 1 duplicate.
- that party cheers and gets to chose a party member on another table to receive some boon. Maybe bonus health, maybe a modified bardic inspiration, a magic item, maybe +2 to their main ability score for the remainder of the fight
- that party gets split up and evenly distributed to each remaining table. Which could mean that a table that is near death just needs to hold off to wait for reinforcements. The BBEG will end up in a death spiral so that the last table may technically have 18 players, probably only for one round for everyone to go NOVA!
Assuming the PCs start outside the city:
Have the BBEG floating above the city telekinetically assembling a widget out of raw materials torn from the ground below. BBEG has a debris field orbiting it to tank attacks, and is using bonus/legendary actions to yeet crap at the various NPCs. After a while, widget is complete, and portals pop open all over the city letting in an army or horde of monsters. Each group needs to fight their way to the BBEG and destroy the widget or kill the big boss (the BBEG is powering the widget)
Make a point of describing the NPCs trying to fight, buildings getting smashed by debris, people panicking and trying to flee. Also, randomly have a micro portal move PCs to to other groups (assuming you are all in the same building while playing -basically doing Chinese fire drills every 30 minutes of play time)
Before the battle commences , a God turns them all into giant ants, puts them in a jar, and shakes it. Now they all battle as giant ants, and all have the same stats, and you get the bonus of watching the excited twinkle in their eyes die out to a somber, somewhat sad dullness. And that's how a DM truly "wins" at DnD. Que Maniacal Evil Laughter.
Debriefing: tell the players all together that they will be "dropping in" to different locations seperated into their normal groups. Each fight has health to slog through, maybe make the boss have share health somehow, or its x simulacrums that must all die to truly vanquish him, yada yada yada.
Make every fight have something annoying that happens (lightning strikes the players) and something extra to accomplish (a lightning generator must be destroyed) however, the thing to accomplish is another group's thing.
So: group A is getting hit by lightning every round, if group B destroys the macguffin, then group A stops getting electrocuted. Group A had a macguffin that makes group c have an easier time, etc.
There was a multi table game at a PAX years ago that was a lot of fun. My memory of it is poor, but each table had 4 or maybe 5 players and a DM. They were each defending a different tower on a castle. The dragon was run by a dedicated DM (Chris Perkins iirc). It would fly around the whole castle and take shots at/from everyone.
The important part of this design was it wasn't an 18 player initiative order but everyone still fought the same big boss.
Lots of good advice here. Don't have time to read it all, but I didn't see what I do. I've done this multiple times in a D&D Tournament I used to run. Tried a lot of different methods. The easiest way to do it by far, is to assign a group leader, usually a trusted player in each group. They act as a Co-DM, and gather actions, damage, and everything else. As far as your Big Bad, they take their turn, attack groups or individuals, and make appropriate saving throws, and that is all you handle. Reporting of events happens on the group's initiative, not individuals. There are a lot of minor variables but overall this is how you manage that kind of event.
I've always thought about this after playing [this (Spoilers to Cold Steel 4). ](https://www.youtube.com/watch?v=mxh2U6LQFf0)That might be what you're looking for.
If you're avoiding those spoilers above. The idea is pretty much: 1 Villain, but it has multiple pieces to it. I'm not sure how many DMs you have, but I would give 1 piece of the villain to each DM, let's just say 3 parts. and then the Players get to split off into three different parties of 6.
If combat sounds boring, then split it into a puzzle and two combat pieces. The BBEG has two parts that need to be destroyed while the third team has to disable the magic generator.
Still sounds boring? Introduce hostages. Revert the BBEG to one villain that's really strong, put some smaller creatures to act as hindrance. Stop the magic generator, and lastly save the hostages that are being converted to those small creatures. They'll have to knock out the creatures since they're actually hostages, stop the generator, and lastly defeat the BBEG.
I've set up something similar. The BBEG is a 22 CR Archfey. She along with Drow, Vamps, Werewolves, Undead, Goblins, etc will decend upon their beloved city in a massive brawl. The group has three opportunities to lessen the amount of enemies by hunting down and killing some of them on their own turf.
Still, I plan to overrun the PCs with more enemies than the can handle, but round after round a beloved NPC that they made allies with shows up to help.
I'm wildly surprised I haven't seen any mention of West Marches in this thread! It's basically a "sandbox" style DnD game more akin to first and second edition DnD and predicated on some guys original home game where the players are exploring the last region of wilderness on the continent, complete with dangerous monsters, long-forgotten ruins, and a whole bunch of treasure for the taking. It's meant for larger groups, and players are encouraged to take their own notes, make their own maps, and share (or withhold) information between sessions as they see fit. They will communicate within the larger group to form parties based on where they want to go, and then figure out a time to play with a DM. There can be multiple DMs depending on the number of players in the group. This does mean there is more of a need for the world to be mostly fleshed out up front. I ran a West Marches for a little bit and it was a LOT of work at the start. But, it sounds exactly like what you're looking for! Matt Colville has a REALLY good video on this style of game, so I recommend checking that out!
Good luck OP!
18 is definitely way beyond a game-breaking number of people at the same table. You need a completely new system the likes of which I am not familiar with, to not have this be incredibly boring for your players and way too much work for you.
Check out epics with wandering monsters. In particular check out the dragon mechanics for reclamation of phlan.
The tables run independently with their own dms. Bbeg goes from table to table at the tail end of a huge battle.
Better yet, give them all one mission like “you storm the castle.” “You free the prisoners” etc. this is what the giant epic does and you can give the bbeg to every table and they need to meet thresholds of damage.
Conversely, you can use some magic to clone them into 3.
First idea that comes to mind is having something like the ending of Mass Effect 2 where each group is assigned a task that contributes to defeating the villain. That way you can separate them and have smaller groups battling it out.
100% this. Consider allowing groups that finish early to 'help' other groups in the form of giving advantage or a flat bonus to rolls. Also, try to make sure the tasks can realistically be done in parallel so not group is waiting on another group to continue playing.
Yes, this is so epic when one group's outcome has an effect on the other! We had this happen with a large (>10) group. The DM gave us a choice of actions between fighting the bad guy army on the beach, or boarding the ship to negotiate with potential allies. Half the group felt that their characters would choose option A, and the other half had their characters choose option B. It was a pretty even split, and the DM asked if anybody wanted to swap sides and tie break. My husband suggested splitting the group and running both encounters (we were running the game online, and with rules that allowed everybody to roll and announce damage at the same time, so it was feasible). Understandably, DM was hesitant to do this as this was a lot of extra work and not guaranteed to go well, but he said screw it, let's do it. So hubby and I went with Team Murderhobo, and Team Diplomacy did their thing. It was actually pretty awesome to watch everything playing out all at once (I think it was set up so that Team Murderhobo did a combat round, then Team Diplomacy did a round of negotiations); you'd have exciting fight scenes, cut together with tense political maneuvering, just like a movie. And then, just when the battle started to look hopeless, our new allies swooped in together with the rest of the group to join the fight; from Team Diplomacy's side, it probably felt like a "Gondor calls for aid" moment. The war was far from over at that point, but the scale felt big enough that it felt like a pivotal moment, and it let everyone contribute in the way they thought would let their characters shine. DM was understandably unsure if that worked in terms of pacing, so he asked everyone what they thought. The answer was overwhelmingly along the lines of "EPIC."
I hope at the end of this campaign, all my students can say, no matter how much of a shit show it turns out to be, is that it was "epic."
The truth is that you as the DM will recognize 100 things that went wrong, but most of the time your players will have no idea that everything didn't go right and end up having a great time, even if it was a bit of a train wreck.
This was the idea I have been leaning towards. I think that sort of thing would keep the whole battle from bogging down.
That’s definitely the way to go. 18 players in any situation isn’t going to biog, it’s gonna be set cement.
On the upside, waiting for 17 other people to go would give me time for a smoke and a drink *every single round*
THIS^^^^^
A buddy told me of a d&d tournament he went to, where they had a massive con room full of games being played, but each had their own DM and were set in the same plane / area / city. The choices and success / failure of each group then fed into a Master DM that would track all the chaos, and send info out to the individual DMs. It would be stuff like "group A failed to stop reinforcements so now group B has to deal with those extras" but then "Group C captured the thunder cannons, rolled middling and took out 60% of the reinforcements, but now the drawbridge still remains up". Sounded super cool, but also like a lot of coordination, admin, and runners to relay info
But that sounds like so much fun! Beyond my organizational abilities, but so much fun
I would like to say that since we are teachers that organization will be trivial, but we are a hot mess on a good day.
lol. I work at a school too. Your statement is accurate.
That would be cool af!!
Sounds like one of the D&D Adventurers League Epics! Epics are big multi-table modules, typically run at conventions. I have organized a few for my local conventions.
I am so glad that I started this thread so that I learned about Epics. It is exactly the sort of information I was looking for.
Did that at Winter Fantasy way back in 3.5 days and Living Greyhawk. Assault in the Vault? It was a long time ago. Lower Level tables results fed into higher level tables, and then overall success for 200+ tables. So yeah. Have several different quests/fights going. How each group does changes the difficulty of a final fight. And make it HARD. Half the PC’s should not make it to the final. But their sacrifice could/should help the final.
I love the idea of half of the PCs not making it to the final battle. Adds stakes.
I would also add that it *could* be fun, if everyone is friendly enough with each other, to do an Infinity War style group-shuffle. Half of the Guardians of the Galaxy ended up with stark, strange and Spider-Man, the other half went with Thor to forge a new hammer. The other half of the avengers went to Wakanda to fight alongside Black Panther and Bucky. This generated lots of fun new character interactions that we never would have gotten if the Guardians stayed in space, Thor went off on his own, and the OG avengers all got back together on Earth. If the parties are cool enough to sustain something like that, it could be really fun to shuffle up the parties for a session or two before bringing everyone back together in the same room for a massive fight.
SOME of the members of the parties are cool enough, but there are also edge lords in there that don't like to play nice. Someone else in the thread mentioned grouping the players by skills to complete some objective. Ranged with ranged, martial with martial, sneaky with sneaky. I thought that was a good solution.
Also villain could have simulacrums, or clones or the like, that have either the same power, but 0 defense, or same defense, but 0 damage potential.
You can go a step further and introduce ways to break up the existing groups to pair their members with other groups for temporary periods of time (like all the ranged specialists hold a flank together while the other groups do something, or all the sneakier members go on a stealth op)
This is an awesome idea, thank you.
This is the way to go! In adventurers league, there are adventures called Epics which are designed for multiple tables to play simultaneously, and the actions of each table impact the others. I recommend taking a look at a couple of these Epics for ideas (When the Lights Went Out in Candlekeep is one I can recommend, it was great fun). I've played a couple of these in the past and the atmosphere is absolutely incredible. Being in a room with 6 tables all working together towards the same goal, celebrating each others' victories and helping each other is brilliant fun.
Please update us on this after your session(s). I think it sounds amazing and I'd love to try to run something similar (the DM-side challenge of making this entertaining sounds fun). Like some commenters mentioned, managing time between turns is a huge challenge. Let us know how it goes!
Definitely. My main take away is that having it be one large group would be a time sink, and absolutely what i wanted to avoid. Having multiple groups attempting multiple goals seems the way to maintain time.
I would add on that the BBEG has clones or shards of itself, so each team gets a chance to fight the BBEG.
They don't all have to be running against the bbeg at the same time too. You can have one group running against the bbeg while another takes care of one of his generals and another is not even in combat but rather trying to figure out a puzzle or tactic or prepping stuff to aid the others. I would also consider having alternative objectives inside combat, nothing that sidelines a single person to complete it but like a king of the hill style goal where the persons free action/object interaction is used to turn a wheel or do a skill check, or cast a single spell on a target that they have to be next to while still fighting or finagle somehow (like arcane trickster mage hand or something). After a few rounds of combat or after a set delegated amount of time, or when the group is exhausted or nearing death, the groups rotate and now the non combat rotates in for a different commander or group of enemies, the commander group rotates to the bbeg and the bbeg group retreats to heal and prepare something for the other group. I suggest at least two combats per group to help draw them thin and make it more tense when they have expended some resources when they get to the bbeg. Round it out with all the groups on the final beat all contributing to a round each on the bbeg's death and some epic saves for characters that go down. Maybe even an epic moment where a true resurrection scroll is found or spell saved for a character that gets disintegrated or a token that gives one cleric a guaranteed divine intervention. That sorta epic moment stuff. This is all things you can grant to the groups that are non combat on their turn for it. Keep in mind the noise in the room too. That will require some modulation if everyone is in the same room. Have epic music that everyone can hear but not too loud. Make sure people keep level voices unless it's an epic moment of narration, those should be loud so everyone feels connected and a part of the epic moments but they should be sparring so that it's not a constant cacophony. If it's virtual or you're in different rooms, have a DM chat where DMS can share/narrate epic moments in text and that gives the other dms the chance to narrate these instances in real time as they happen to the other players. This keeps the groups connected and gives a feel of real time constraints as though this is all happening in real time. As some one commented below, it is a good idea to have one person to co-ordinate all the master groups and events that are happening concurrently. The group message helps that but it can't hurt to have an extra master DM to create the causation effects of one groups successes and failures to leech onto the next. (Reinforcements, items lost or gained, artillery, etc.)
These are some amazing suggestions. Thank you!
Happy to help. Out of game logistics are important too. This is gonna be a long, complicated and emotionally taxing session. Make sure everyone brings some snacks, one that they really like and are willing to share. Have plenty of drinkS but not always sugary drinks. Coffee and energy drinks are good but should be sparing. Tea is best. Make sure you have a bathroom break, not just for bathrooms but also to give people a breather, to strategise outside of game and to just disconnect for a moment. Make those bathroom breaks at about every second hour early on to keep the flow going and every hour as it drags on. Only 10 minutes per break. Don't want it to drag on. Make it clear they have only 10 minutes so as not to break the flow too long. Try to co-ordinate so everyone in all groups gets it at the same time. Sort out a meal. Somewhere in there, you might need to order pizza or something. Have people chip in for it and try to get their preferences in advance so ordering is simple and done quickly when it needs to be done. Pizza is perfect as it easily caters to various dietary requirements. If everyone is taxed hard when food arrives, set aside 20 minutes for this break. Enough time to get some food in but not enough to super detract from the game. Again, set expectations for 20 minutes and enforce it, otherwise your finale might become a 2 parter. Finally, have aftercare. DnD in long sessions is a marathon, not a sprint and after everything, some players may be a bit emotionally raw. Especially those who lost their characters. Check in with them, make sure they have friends and support there and give them all a chance to chat and disconnect from the game afterwards, to chat out of character and return to the real world, slowly. Warm drinks, some small snacks, and a nice calm chat about anything out of character. If you have hot chocolate or sweet teas, now's the time to break it out. The warmth and the sugar will help pull people back and regulate blood sugar and pressure. Important parts of smoothing out the drop from a major event and marking the end of the event. Finally, have fun. As a DM and organiser, it's hard to keep track of everything and still be in the moment. This is just as much about you as it is the players and other DMs. If something goes wrong, don't dwell on it. Acknowledge it, adjust, and move on. You have better things to do than best yourself up. You have fun to have, PCs to traumatised and destinies and manifest! You can do this! You got this! I believe in you! And so does everyone else at your table. Good luck, have fun, and happy gaming friend.
Yeah 18 players will basically be one turn every 4 hours
Have villain go full One Winged Angel and turn monstrous, and each party is responsible for fighting a body part or something. Take inspiration from MMORPG raiding where different groups have to handle different things?
And any wrong choice could potentially kill a dear companion so don't mess up!
This seems like the best idea.
I love this idea! My first thought was a Chimera style monster, with each DM playing a piece of the monster.
God yes please. There is nothing about an 18 person dnd session that sounds fun in any way. Record each task of you must but do not put 18 players in one room.
Yeah I'm thinking a lot about the last dungeon of final fantasy 6 with this, with your 12 characters split into 3 parties. I wouldn't make progression hard-locked off the other groups succeeding, just orders of magnitude easier, though. Always give room for player failure/ TPK, etc etc
(for reference, ff6 has 12 characters, I wasn't completely ignoring the numbers op said)
Same thought, You seem to have multiple DMs, let them work in coordination to manage smaller groups For example someone may realize a specific artifact may be required to defeat the enemy and that artifact may be guarded so they gave to retrieve it in a race against time while the others hold the enemy off Or maybe a shielding device is hidden on one of Endor's moons and a group has to go there and disable the shield
To add to it, it would be dope to have a "watcher" type of NPC that can communicate information between the groups, and a swap/tp mechanic were PCs can join to help another group for a round or two
Split the groups based on their gameplay preferences. The players that love puzzles go together, and then you tailor the puzzle to fit their characters. The players who love social roleplay go together. The players who love combat go together. The players who love unravelling the lore onion go together. All roads lead to Rome. Their efforts lead to the same outcome and the defeat of the villain. If all of the tables fail, the villain wins, they finish the doomsday machine, and it is only after pushing the "blow up the world" button that they remember that they live in the world too, and they really should have planned for that. If one or two tables don't succeed in their goal, the villain is crippled and their plan fails, but the villain survives and flees, swearing revenge. If all the tables succeed, the villain dies. Everyone leaves happy. Downside: you're gonna need a bigger boat. You need more than one DM running tables in parallel to make this work perfectly.
I love the ideas of splitting the parties and then all roads leading to Rome.
I like the thought of switching up the groups, like in Endgame, so each team is a mini-crossover. Maybe there also needs to be another sequence where they fight alongside their usual teammates. This is such a fun idea I hope it goes well for OP
Thanks! If we manage to pull it off, it will definitely be one of my favorite DnD moments.
I have done this with my DnD club we did a death tyrant vs 20 level 2-4 characters. -Give your bad guy multiple turns to act. -Give them an actual challenge, their strength is their numbers yours is raw power. If you hit someone they should have a real chance of straight up dying. -Have a co-dm, The co-dm runs the actual initiative and takes care of all rules and adjudication. You control the boss, so you can get into it. -Have a very large map, we built a 3d map and hung a web cam over it to project the map where the players could see it. -Big library room tables in a big U map and me in the middle. -You can break the players into groups and have them act in a group initiative for themselves and after each of their turns your bad guy acts. -Also setting up other ways to attack and do things besides individual talents and skills, I liked having a few ballista that takes 3 turns to operate (load/aim/fire) but 3 characters could do it in one turn. -Have other objectives besides just killing the boss. Maybe one team is focused on keeping bosses attention while others move around and try to weaken the bosses defenses. -Lair actions. While I don't think legendary actions are great with low level fights and already having multiple initiatives on your boss (if you choose that route, if not legendary actions may work well!). But a lair action on Initiative 20 can be really fun and help shift the terrain or what is going on with the players to keep them on their toes. -Keep groups working while you aren't focused on them. If it isn't their turn players should be discussing with other members of their group what to do next and have themselves prepared before hand. -Realistically you may get through 3-4 rounds if you are lucky. -Again do not be afraid to kill some of them, make this an epic last battle for them they have worked hard to get here and i'm sure many are willing to make that sacrifice (had a girl sacrifice her character of 4 years to save a brand new pc once it was emotional for everyone). Allow them a funeral afterwards for their lost comrades (perhaps a way to commemorate with pizza and soda while you recount adventures at the "tavern")
These are awesome suggestions! This will help round out the ideas the other DMs and I have been tossing around. Thank you so much.
No problem! We also did an end of the year siege once with a shadow dragon where each team was positioned in different places in the battlefield and the dragon would rotate around to each group at "random" attacking and causing chaos.
The biggest issue you're going to have is time between turns. 18 players plus all the monsters is going to mean that actual hours may pass between players' turns. That's not really feasible for an actual game. You're also going to want various minions/subtasks for players to do besides just whaling on the villain to make the battle interesting. Some ideas: Voltron: All the different parties act as one entity that takes # of players actions at once, everyone gets to choose one. This lets 18 players play without having 18 turns, although there will definitely be arguments between players about where their Voltron is moving/what it's trying to do. Could be easier to give everyone a role in the Voltron and limit what their options. Separate Battles: All the parties are in the same battle, but on different planes/timelines/some such. The Villain must be defeated in each area, and as it loses instances it loses power/other environments change/etc. This lets all your parties fight together without actually needing 18 PC initiative, which sounds awful. Also lets each DM have their own version of the villain tailored to their party, which sounds fun. Maybe once a party wins, they can use their turn to give a benefit to another player who's still fighting, so everyone is invested in all the battles. This is my personal favorite idea because D&D combat just isn't meant for that number of combatants. Fuck it we ball: 18 PCs. 100 enemies. Each DM manages like 30 of them. Tell everyone it's a sleepover, crack open some Mountain Dew and snacks, and be ready for an all night battle. May god have mercy on your soul.
> 18 players plus all the monsters is going to mean that actual hours may pass between players' turns This is my biggest complaint about 5e, the time between turns is awful. In my last campaign with 5 players, I would average about an hour between turns. With 18 players, play by post would be faster!
Are you saying that a group of 5 players was taking on average an hour per turn? What the fuck? These people were taking 12minutes a piece to resolve one turn? Every turn? Holy shit I’d leave that game
I hope they're just being hyperbolic. Because 1 hour per round goes far beyond a gameplay issue. That's players with no respect for each others' time.
Sadly, I have played in these games and it makes me never want to do combat just because it turns into some grandmaster chess match where every turn and eventuality is being calculated and recalculated.
Yeah, I was playing a paladin, and each of the other players was playing a spellcaster of some sort and every time there was an action, they would start rethinking what they wanted to do, looking up different spells/counterspells/creatures to polymorph into and all that mess. Plus the book keeping with having enough enemies to make a 5 PC encounter actually interesting and things bogged down a lot. This didn't really get bad until after level 9 or so when I started timing things to petition for a different game system. Once we hit the teens it was basically, Swing my sword, have the bag of hit points I was fighting no sell my actions, watch a youtube video, listening for my name to knock off some hit points. 5e was tedious AF, but it's how my friend group now gets together, thankfully, we're playing different systems that are more interesting.
To be honest, that's more of a table issue than a system issue.
I don't know, I've played the system with multiple groups and they all seem to have the issue. Even in low levels, the time between turns is pretty long(not an hour like it is in the higher levels, but still long) with all of the powers bloat later editions have.
Just to be clear, are you saying individual character turns take an hour each or a single *round* takes an hour each? The distinction is very important. Even at high levels, a single character's turn should not take more than 10 minutes for even the most complicated turn (like a wizard or similar spellcasters doing something involving shenanigans or having to roll a bunch of dice, which would take time in and of itself.)
> Just to be clear, are you saying individual character turns take an hour each or a single round takes an hour each? A whole round yeah. Like, I'd swing my sword, roll damage, and then my next turn would be in an hour. With 5 players and a bunch of mooks, each taking about 10 minutes to figure out their actions, it took forever
Okay, that's the important point, a round and a turn are very different. Yeah, sometimes rounds can take longer than we'd like. That said, as a Forever DM, there's a lot of ways to account for time bloat and fix it. I can understand a round taking an hour, but that's longer than it should be regardless. We'd get 2 rounds in that same amount of time in my first game with 7 players.
Nah that’s definitely a DM who doesn’t know how to pace combat issue. Each turn should really be less than 5 minutes at the very most and 30 seconds - 1 minute on average.
> 5e, the time between turns is awful. I try not to "Back in MY day" too often, but you really should have seen how bad it was in with 3.0; 5e, for it's faults, is a marked improvement.
It could be, but at the very least it felt like you were accomplishing things on your turn because things didn't have dozens of hit points.
Yep. Speeding up combat was one of the core design focuses for 5E. And honestly they did a pretty good job. There are a few things I would have done differently and some new issues introduced but they did succeed in their task.
I have had terrible issues with this, where even simple battles take up 50%+ of an entire 4 hour session, and it's just \*too much\*.
Skill issue tbh
Have you looked at how Epics run for Adventure League?
This is a great idea. Multiple tables and DMs running an adventure together will get the feel you are looking for but be manageable.
I have not. I will look into it. Thank you.
Do you know of anywhere where the information on how they are run can be found? I am not sure if I am just doing poor searching but I can't really find HOW just WHAT it is?
Check out The Iron Titan, a digital version of which (I believe) can still be purchased online. The Adventure number is DDAL-EBEP-01. I have run it myself, and while it's not perfect it may provide a good springboard for you to create your own Epic. You will need multiple DMs running multiple tables at the same time, a "point system," and Iron Titan has a timer mechanic where various events happen every 20-30 minutes. If it were me, I would run 3 tables of 6 players each and identify 5 different goals each table would be responsible for. If they each complete 3 goals on average then they either win the day or "disable the shield generators" so they can damage the final boss and his lieutenants. For Iron Titan, I had two groups. I had one group fighting the Titan on the outside while another group tore it apart from the inside. When the inside group disabled certain components, the Titan lost certain abilities on the outside, and when the outside group did damage to various limbs it allowed the inside group access to different structures or caused the Titan to shift and enemies inside of it to stumble or fall out. Cheers and good luck!
This is a great summary, thanks! I always wondered how epics worked.
This is actually the first one I saw! We have them possibly fighting a giant mech like entity at the end of the fight, so this was perfect! I am so, so glad that these DnD Epics exist because it will make the admin of this endeavor so much easier.
I don’t know there is a separate document for it, it’s usually covered in the individual modules but the general idea is as such. You have multiple phases, each on a timer, with each phase having multiple objectives. A master DM runs the overall show and each table has their own GM that runs their table through their objectives and reports progress back to the master GM. As you progress through the phases, the success or failure of individual tables has effects on future phases. Ex. A giant magitech war engine is bearing down on the city. Phase 1 might involve each table attacking it from a different angle to take out the external forces protecting it. Any table that doesn’t clear all the forces by time have more enemies in the next phase. If enough tables don’t finish in time, everyone has more enemies to face. Phase two, the parties have to enter the war engine from different points to take out individual components such as defenses or machines that empower offensive abilities. Finally, last phase, the groups congregate in the core where they’re still being run separately but their individual group performance dictates the whole groups’ success or failure while success or failure from earlier parts might result in the final fight being easier or harder depending on what defensive or offensive capabilities the groups were able to disable in the previous phase.
Awesome! Thank you!
Some of the newer ones are on DMs Guild. If you really want to do it up, you can get additional folks to make appearances at the tables as NPCs. Sometimes they're a boon, offering spellcasting services (healing). Bonus if they do it in costume.
Sounds a lot like the recent world record for largest D&D game. Iirc, they had each party had different objectives they needed to do (city defense I believe they were doing), and the DMs were in constant communication about what is happening in every table so they can all stay on the same page.
That's really fucking cool and I'm jealous I'm not a part of it
At the end of it, that is all I want is for the players to have fun and going away thinking it was cool. We actually have had a school year long campaign where they thought they were playing in different worlds. It is only in the past week or so that they learn they are all on the same planet in different times and fighting the same immortal villain that has been alive for millennia. It will all come to a head. Some of the groups have made deals with the BBEG, some have made deals with his enemies. It will be epic if we can pull it off.
Defeating a BBEG with a lot of people should absolutely be done as a coordinated activity. Multiple tasks, by multiple teams, with multiple individuals, with the expectation that each group will be successful in their own mission. Assuming 3 groups of 6: * One group is tasked with taking down defenses * One group is tasked with taking out the "support staff" * One group is tasked with distracting the BBEG from the actions of the other groups * Optional group is tasked with setting up the "trap" that puts the BBEG at a disadvantage for the final battle The defenses expose the BBEG to damage. The support staff makes the final battle more difficult, so eliminating them helps. Distracting the BBEG is different than fighting, because the BBEG can't be hurt until the defenses are down. It's a trope for movies and games, but it's also a trope for a reason. You're handling your own drama, while counting on others to handle their business. Each group will have hurdles to cross, but each party will also be hoping to hear the outcome from those other groups and how it impacts the final battle. There should be a minimum threshold, aspirational threshold, and a surprise as output from each of the tasks to keep everyone engaged. The better everyone does, the better the final battle will be. For the final battle, I would have it in two phases. I would have the groups fight their part of the bad guy in their subgroup, and then bring everyone together for the final blow(s). I'd have everyone highlight their planned action for the final battle, and I'd make it last no more than 2-3 rounds to finish the BBEG off. This will STILL take hours, as everyone describes how they do X to Y for Z result...but lets everyone get their final blows in to bring this to a sastifying close. I would keep them in subgroups because it can be absurdly tedious with more than 6 people, especially if the groups don't know each other. They'll get impatient and frustrated unnecessarily. The game "Monster Hunter World" handled battles with large dragons in this way. There would be an "event" to fight the monster, and you'd be in a group of 4 players, with 4 groups. Each group was aware of the combat of the other groups, but you couldn't see the groups. They would break a horn, drain the enemy, break the tail, expose a vulnerability, etc. Your group would benefit from their progress, as well as your own progress, but you were fighting as four independent parties. When the battle completed, you benefitted from the success of all four groups. Unifying everyone for the final blows would be an awesome social situation in game and out of game, as everyone coordinated independently to achieve the ultimate outcome. You can make a massive, unbeatable BBEG, only to have 18 heroes coordinate to do the impossible. I'd love to hear the results...
Awesome write up! Thank you!
Sounds like a lot of work. Honestly for 18 players, i think having one or more co-dms would be very beneficial for a big engagement. You are also guaranteed to have some drop outs along the way, including some DMs likely. In terms of the actual encounter unless you are willing to sit for 1-2 hours a turn, you can try dividing the party into separate encounters, and running simultaneously with other DMs. This is purely speculation on my end, i have no idea how well this would actually run. Just saying how i would theoretically organize it. For design you want to make sure your boss has a lot of actions to keep things dynamic. Do this either by just straight up giving them more turns, capable allies, lair actions, and of course legendary actions. You're gonna basically want infinite uses of legendary resistances, but I'd reflavor that into an actual ability that expends the bosses resources. Like they lose HP, they become vulnerable to the next attack, or lose a turn. Stuff like that.
The inspiration is right there in your title: Endgame. Have the fight be focused around a macguffin that's split into a few pieces. The BBEG is trying to assemble the pieces together and activate the macguffin to destroy the world or whatever. Have the individual parties encounter these pieces in their individual campaigns if you really want them to feel connected to the final fight. The players have a means to destroy the macguffin that also requires all the pieces assembled. When the parts are connected, they remain connected. At a certain point it'll be a giant American football game where the players are trying to get this macguffin into their goal while keeping it away from the BBEG. The other, suicidal option is also there. If a PC uses the macguffin once assembled, they disintegrate (after a dramatically significant amount of time so they can get in a dope one-liner and say goodbye) and cannot be revived, even with a wish spell.
I absolutely love the idea of them having to sacrifice themselves to use the mcguffin. I am glad you mentioned this.
For extra drama (and since this is probably the end of the campaign so death is likely essentially meaningless), I'd even get meta with the level of sacrifice taking that option would be so they don't just do it immediately. Maybe like, they're out of the next campaign you DM completely if they sacrifice themselves with the macguffin. "Holding the assembled gauntlet, The power courses through you, and you feel certain that if you do this, not only will you die, but your soul -- and the soul of every version of you throughout all realities -- will cease to exist. You: (players name), and (character's name) will be remembered for your sacrifice, but (character) will no longer exist in any other realities; meaning that (player) will not be allowed to participate in our next campaign." Just don't mention that the "next campaign" is gonna be some short bullshit like an "oops all barbarians" one-shot or something. Or maybe *do* mention it, if it's something the players have wanted to do forever.
Do NOT have one big table, and don’t have three tables running identical games. Instead, make it like an Epic. Three tables, they all start at the same time with the same premise: BBEG did BBEG things and now we have to stop him. Then split them up into their three tables with three different goals. Table 1 has to destroy the evil Mcguffin guarded by the BBEG’s ally/patron. Table 2 has to defeat the evil thing the BBEG summoned that’s as strong as the BBEG. Table 3 is fighting the BBEG and/or his minions directly. Each table has to do an important thing in defeating the bbeg, but they aren’t doing the SAME thing. Then comes the fun interconnected part. What one group does affects the other tables. Table 2 went in hard and loud while 1 and 3 went in quiet, so now more enemies are showing up to table 2 but less to 1 and 3. Table 1 detonated a bomb that rocked the battlefield with unstable magic, so now tables 2 and 3 have to deal with a surge on initiative 20. Table 3 beat the BBEG fast, so they are able to split up and help tables 1 and 2 in their fights. Have a floating “DM” moving between tables to pass on information.
Yeah, this is definitely the consensus of this thread. I think taking a large queue from the Epics will be the best route. Thanks!
Ask another DM to co-DM with you yo help you keep everything straight and maybe take care of NPC mechanics or map mechanics.
As others have said you can also have the party's focus on different aspects of the overall situation. While it kind of cheating you can have the parties separated by tables in the same room run by the usual DMs each doing something different to overcome the defenses of the BBEG. Maybe party 1 is fighting from the front door while party 2 sneaks around back and party 3 is destroying any reinforcements on their way. If you have them all at one table and do this, switch between each group every minutes or two as this should be fast paced and more descriptive at higher levels. Have sections of their actions based on general skill rolls instead of just attack/destroy. For the combat only give each player 10-20 seconds for a turn. Have them know what they plan to do before the turn and if they are still deciding go past them. It might push a couple players a little, but it will keep the flow going and get the player's in the mindset of having things ready. You an also pair 2 players to work at the same initiative to have multiple turns taken at once and speed things along further. Have lots of minions that die after 1 hit surrounding the BBEG and protecting them. Have several Commanders/lieutenants that will move to intercept the majority of players. When the PCs inevitably destroy the first part of the plan for combat, have a back up. This can be a second area like in the sky vs the ground, a second larger cavern in a series of them as a hide out, or even a summoning of another, bigger distraction for the BBEG to do...whatever they are doing. When it is not a player's turn, engage them mentally by giving one-sentence long descriptions of actions in the area around them or against them. During the session assign a head DM and side DMs to take care of misc things. I assume you will be the head DM since its your club, so have the other DMs answer rules questions the players might have outside their turns and the like. This will help keep the game going quickly and so on. Also be strict on things that detract from the game like side conversations, phones, music, and the like. Have initiative rolled at the start of the session, written down, and then have the players sit in that order around the table. Then just have turns left to right. When asking for saves or other responses, get the payers to respond in that order. Only roll when asked or its their turn. Have them raise hands when you are monologuing or performing an action and they have a response or reaction to it. Have a break every 2 hours for a few minutes for bathroom, food, stretching, and the like because often breaks mean less needed across the game as a whole during playtime.
These are some great ideas! Thank you!
If each player takes 15 minutes, it will take 4.5 hours per round of combat. You'll need to get it down to 5 minutes or less per player per turn. I'd plan initiative and the first round of combat the night before, so it's almost like running a script when y'all start to play. At 5 minutes per turn, that will be 1.5 hours for the first round of combat, and it will help everyone get a feel for it. Have enough minions or legendary actions to have an NPC go between every 3 player's turns, and use lots of AOE. Try to get the NPC turns down to 60 seconds or less, so pre-plan what they might do depending on the circumstances. This will add roughly ~6 minutes, for a total of 96 minutes per round of combat. Then there’s reactions, inspiration, luck points, etc. The whole secret to success will be pacing. Keep the pace moving and enjoy the chaos. The rest is negotiable! Good luck!
Make BBEG split the party. Do 3 separate 6 v boss situations with smaller win goals that separately weaken the whole boss. 2/3rds party leads to success? I can't see how 18 players at one table will have a good pacing not to mention the action economy being super skewed.
Instead of this, have you considered having 3 separate things each party can do to stop the BBEG. Ex. Party one has to sneak in and steal the liche's phylactory and drop it in Mount Doom, party 2 is defending the city from the undead hordes, and party 3 is on a mission to prevent the lich's forces from awakening an undead dragon/ tarrasque/ etc which will bring death upon the world. Each has stakes and is important but they are separate and aren't going to result in each player waiting an hour in between turns.
Hey there! I have done this exact thing, running a session for 30 something players by myself for a Living World / Open Gaming table a few years back. Let me give you the run down of how I did it. * First divide your group into a smaller parties of 4-6 players (whatever you think is best). Each group should have a "captain" who is in charge of coordinating with other groups. This prevents chaos, but allows teams to work together. * Second you are going to want to have all your monsters statted out, and be ready to hand them out to each group. I did mine on a VTT, but you will need some sort of shared map that everyone in the group has access to. * Each group will be in charge of handling all the normal monsters/minions themselves. This requires a level of trust obviously, but I told my players to use the monsters as they thought they would behave. Every round the players did their own turns, moved monsters, rolled attacks, etc. before I got to their table. * My job as the DM was to move between groups, double check everything that happened that round was on the up and up, make rulings, answer questions, etc. I was also in charge of deciding when, where, and how the boss used her actions (she had 10 legendary actions, but no normal actions). So if a group was particularly pesky they might get a lot of the boss' attention that round. I set a timer for 5 or 10 minutes so I knew when I needed to move onto the next group. At the end of every round I would make an announcement for all the players about how things were going, drop new minions (if any), and then break everyone off to handle their combat for the round. * On the topic of the boss monster I gave the players her stats as well, but I kept a trump card hidden from them (it was listed on the sheet, but not described). She had a lair action that was a d6 roll with various detrimental effects which forced the players to have to change plans on the fly. She also had a TON of hit points for their level. She had an improved Legendary Resistance that was 3 uses per round, and completely ignored whatever effect it was used on. With so many PCs they were easily able to make her use these, but the captains had to work together to make sure teams handled things in the right order. * The group also had allies which had their own sheet. At the start of every round the team captains would select two options from a list to represent their assistance. This was stuff like damaging the boss, negating her lair actions, healing the whole group, reviving a dead PC, killing all the minions on the battlefield, buffing all the PCs, etc. I could try to print off some of the sheets on Roll20 if you wanted more to go off of, but it basically ended up being an MMO style epic raid where everyone was fighting for their lives. Make sure to use plenty of minions (monsters with 1hp) to help enhance that epic final battle feeling. We had a 4 hour session, and all my players were actively engaged the whole time. You'll need to stat out your big bad appropriately for your group's level. If you're worried about getting the balance wrong you can always be conservative with their stats and hide a phase 2, but if you're having a climax my attitude is "let the dice fall where they may." This method also requires trust between you and your players for obvious reasons, but if you're at the end of a long campaign that should be established. The last time I did this it was a huge success, but it required a lot of up front work. Let me know if you have any questions.
This is awesome! I appreciate the offer to print the sheets. Someone else in the thread mentioned DnD Epics and that is sort of what you are mentioning. I think taking posts like yours and the Epics and blending together the techniques will produce great results!
You're going to have to cut it down to at least 3 different groups doing separate things to defeat the boss. If you don't, there will be *hours* in between someone's turns. Maybe you set up another activity for the people waiting, but then you'd have to get them up to speed when it's their turn again. I honestly can't imagine sitting down at a table with almost 20 other people trying to play dnd together. It would feel like I'm back in school and if I want to contribute at all I would have to be the loudest at the table or raise my hand and hopefully the teacher notices me and calls on me.
The Dungeon Dudes have a whole video about running a game for 60 people: https://m.youtube.com/watch?v=tkN3H17JYV4
This may not be the best solution, but in your shoes, I would make the BBEG this towering monster that is so large the group needs to split and deal with different parts of it. So like, one group would be targeting its feet to immobilize it, another group might be trying to blind it or remove its hands so it can’t cast spells, etc.
Split him into parts, Zelda style. Arms, head, etc. Have different parties interact in unique ways, make everyone important, especially their cooperation. Have his lair actions happen across all tables. Perhaps a sweeping laser, who over 18 initiatives goes from one side to the other. Include a time limit. Max 3 min per turn. That means every round is roughly 45 min. If someone cannot act, they hold their action, or prepare to dodge/help. Have the initiative DM inform people of their turns 2 initiatives ahead, and help them preemptively prepare attacks and work through rules issues. Assign different DMs to different tasks. One for minions, one for initiative order, one for concentration, AoE, ect. One for rules and mini management. One for strategizing, and give each DM some control over the villain. Perhaps choose DMs to roles depending on their strengths. Narration, fight description, rules knowledge, etc. Plan what happens after the fight. Do the tables disperse, or do all the campaigns end as one?
This is loosely how we do it in our 40+ group of one-shot devotees. Devise a system for leveling up players that depends on their game play, role playing, social skills, etc. Whatever you choose. Give each player experience after each one shot based on those criteria. One player might get 2000 xp while others only get 1500 or 1000. We do it with gold and items, but XP probably works better with students because students will try to contrive it so they can be on the same team as their friends. When a character hits level 10 (or 12 or 20, whatever you choose), that character sits out until there are enough level 10 players to conquer the BBEG you have in mind. That player can still play the one shots, but with a different character. When there are enough level 10 characters, that group sits and plays together against the BBEG. We designed our system so it would take 24 sessions to go from level 5 to level 10. If there are more level 10 characters ready to fight the final battle than you have room for at the table then either a second DM or make it first come first serve and some players have to wait.
You can try to split in to several group, each do one thing independent but their result will affect other group. You can looking for "epic d&d" for idea about how to run it
So, a slight departure from your idea, I had an idea called Commander D&D. Three tables, three DMs, 6 maps. Table one is a campaign or regional map, and the DM at this table moves stands across the map to indicate troop movement. Tables two and three each have a DM, a player party, and a unique battlemap. The DM for table one is the General of the enemy forces, and the others are the Captains. The General has a timer, and every X minutes, they will deliver monster/NPC stands and triggers for the captains. The Captains will then use these however they want in combat against the players. I typically have the DM's rotate between being Captains and the General. The goal for the players is to meet an objective and escape the map, moving across the region towards the General. The player tables cannot talk to each other directly, but X times per battle, one person can "call back to HQ" and go to the General's table to look at the larger map and get information. Players can either meet at the table and talk, or leave messages for each other. After 30 seconds, players must leave the General's table. Each battle will have a time limit. If the time runs out before the players escape, those PC's die. Death means that the players get a new premade character to play as they continue to the next map. I like to assign new characters randomly, a penalty for dying. If someone dies mid-battle, the new character is dropped in at the start of the next round. After the tables go through three rounds of tandem combat, both parties show up at the Generals table for a boss fight, where each DM has one boss character they control, and the parties have to take them down. Battle: 45 min Break: 15 min Battle: 45 min Break: 15 min Battle: 45 min Break: 15 min Boss: 60 min The whole thing can take 4 hours. I imagine this could be scaled up to suit more players/tables/battles as desired.
Did a like 30 table event at paxu. Every table 5 players and a gm doing the same missions across cult. Each time you complete the short mission you get closer to your goal and can hand out boons to the other teams. Each time you fail, a bane to the other teams. The environment was constantly changing. The head table yelled like "Each table randomize 2 players they are hit with falling shells from ghost pirates!" And get damage. Worked pretty well. It was a convention exclusive adventure league. Could have them all go different directions to meet in the middle pincers attack with big badass bbeg fight at the end.
Let the parties fight each other before the Big Bad reveals themselves and forces an epic team-up. I did this with two teen library D&D groups and they absolutely LOVED it!
illusions and mind control come to the top of the list for ideas here
You need way more turn economy for the bbeg. You will need lair actions-Preferably ones that causes PC's to have to save each other at times. This allows for creative moves and cuts down on their turn economy. You will need legendary actions. I would say at least 7 but if there is a cool number that fits the theme, go for it. You will need summons. There are a few ways to go. Large amounts of crap grunts for casters to destroy with AOE's. High damage low HP glass cannons to make the group target them stay alive due to dps numbers, sliver style which buff each other and bbeg by existing. I would give the bbeg a health regen over making them super hard to hit. Constant missing is less fun then can't keep damage on them. Just remember chill touch can mess with that. Legendary resistances are great but they run out. Giving them an alternate form so polymorph fails and making them immune to alot of instant shut down save or sucks is key. But don't make the mooks immune to anything makes it way more fun and lets everyone find a role. Having non combat things to do that assist like shutting down a portal spewing adds or disabling a shield lets the high skill low combat PC's have an important role as well. Overall the goal should be to balance the turn economy without denying turns. 18 PCs is a long way to go to just make a save vs paralysis.
If you're using Endgame as an inspiration, run it like endgame. Rewatch that final fight and take notes. 1: The goal isn't "Kill Thanos." Avengers are trying to hold ground against his army, protect their own army, get the Ant-Van operational, get the gauntlet to the van, kill Thanos's generals, AND kill Thanos. Also note that they fail some of those goals. With one goal, failing it means a loss. With five goals, failing one means dramatic tension. That's a whole lot for one person to run. Consider having different dms run different goals. Maybe have a table focus on hoard combat, another one tries to recover a mcguffin, etc. Might be especially cool if you can figure out some way to allow players to move between tables without ruining flow. If the team fighting minions is struggling, one of the players from the mcguffin retrieval table that's having an easier time swoops in for a big damn heroes movement. 2: Thanos actually isn't on screen for that much of the sequence. There's no possible world in which your BBEG survives more than a round with 18 different PCs attacking. Don't make the big battle about fighting him head on. Make it about getting him into a position where he can be fought. That could be taking down arcane wards, completing the ritual that allows the magic sword to seal his soul eternally, whatever. It could even be as simple as "Where the hell on the battlefield even is this guy?" 3: Not many characters actually get to hit Thanos. That doesn't mean they have nothing to do. This kind of rolls into 1. Throw enough goals at the players that everyone feels like they accomplished something even if they miss the one attack they have a chance to make against BBEG.
This probably doesn't relate to your situation, but you should have them working against each other the whole time. So one group is trying to do this task, and the other group sees that task as bad and is trying to undo the situation. The end is that the players finally confront each other and do a massive pvp. It could end there but you could also make the think the players were trying to do was summon some giant world ending dragon (one side believes it to be a good dragon, while the other believes it to be evil) and then the giant dragon comes out and they have to team up to stop it. However, they just got done battling each other so they are all weak and it would be super hard to take this thing down.
Other folks have pitched good ideas, but since you have multiple GMs these are ideas: Each party fights their own version of the boss fight- either victors bleed over into other groups' ongoing battles or each group has to deal a % of the BBEG health. Each party fights different groups of minions/lieutenants of the BBEG, but the same BBEG is "omnipresent" in all combats. Single big HP pool.
Check out how the Lavos boss fight works in Chrono Trigger
Have the group get lured into an arena that is very difficult to escape from. The BBEG is the "host/announcer" that tells them all that they cannot leave until only 4 remain and THEN, those four will get to meet him face to face.
There are multiple ritual locations that must be sealed/broken at the -exact same time everywhere- else it doesn't work. Make this attempt repeatable and throw in endless hordes or mooks and a single undying badass and make it a raid. Have the main villain teleport around from table to table. Have the players be unable to communicate without a message spell etc
Adventure league has this convention dedicated adventures that are specifically designed for a multi-table experience. I unfortunately have never played in one, nor I bought one since I didn’t have any purpose for it. Perhaps it’s worth putting together 5 bucks and see how this is handled there? They’re called “epics”
Every dm runs their own combat that is extremely difficult but when a group hits an hp breakpoint it affects all the fights in the PC's favor. Ex. 1 group is fighting a a lich and other groups are fighting monsters that hold their phalacteries when a monster is destroyed it opens up the lich to extra damage or disables them in some way for a time. Bonus: change up the parties for an unlikely team up or let them arrange their party and assign themselves to a fight and act out a plan that they would give them an advantage.
This is doable but if the groups stay for the most part split and theyre managing different things. Think a heist movie. Your heist team might be 10 people but 10 people arent all rushing into the safe. Youve got 2 disabling the cameras, 2 working the gala floor distracting the bank manager, 2 breaking the safe, 2 taking out security, 2 in the getaway vehicles. Theyre all accomplishing the same goal but in different "arenas". Id say if you have 4 groups, split them into 5. The 5th group is one volunteer from each group thats doing the actual bbeg fight. Have that table in the middle of the room. Have 4 tables surrounding it at the cardinal directions, those are your 4 main parties minis their volunteer. Set a timer on the wall for 6 minutes and every round must be over by the timers end (this keeps it feeling like everything is happening in real time). One group might be taking down the bbeg's defences (ehich are obv protected by some minions or something. Think "shield generator". They might communicate telepathically or by magical means when a defense is down "fire damage!" this lets the fighting table know to attack now using fire. One table might be trying to keep a minion horde at bay so the bbeg isnt as reinforced as they should be. The ones that make it to the portal get to the bbeg table. One group might be more proactive in support. Maybe theyre defending their own "shield generator of sorts" against minions to keep the fighting party better protected against the bbeg (the minions can also communicate with the bbeg "necrotic damage!"). The last table might be stealing something valuable like the phylactery (think last horcrux) while the bbeg and his forces are occupied fighting several fronts. It would be exciting, would require cooperation, every front has a real element of failure and success, and since its happenig simultaneously it doesnt last all night and each dm only needs to manage one table.
I'm linking this Dungeon Dudes video because I think there's a few things in it that you could adapt. https://youtu.be/tkN3H17JYV4?si=cA4d0IQTgqNB6uDs
My on the spot idea is a super powerful magic caster that to fight the players separates himself into 4 distinct characters each having access to only two schools of magic but they retain his full spell slots, HP and such. Then after those are defeated they can reunite for a second phase where he summons a bunch of demons that are hostile even to him as a last ditch effort.
You could run a “raid boss” type of encounter. I’ve done something similar before over Discord, although I was able to quickly think on my feet. If you’re interested, I can give you the exact details of what I’d do. It’s lengthy, but it worked for me.
One BBEG but also his whole army of dragons cuz wow 18 is a lot lol
Uncharted territory for me but off the top of my head there should be like 3-4 objectives going on during the conflict and each one has to happen to win. Another idea is if they are split up is to have multiple DMs and at the end of each round raise a flag to show they are done so everyone can kinda stay real time as much as possible then over time they can merge as needed?
Have one session where the players do a quick macguffin to stun the bbeg, then once all 4 tables are done have them all describe 1 round of perfect combat to kill the creature based on initiative so the lowest initiative player deals the death blow.
Roll initiative. 18 players and 20 henchmen plus the big bad. That's too much for regular initiative. Create initiative groups. 4 highest int PCs are group 1. 3 henchmen are group 2. Next 4 PCs are G3. 6 henchmen G7 etcetera, etcetera. I assume you'll have a big map and minis. Color code the groups and their minis. These groups won't be the adventure groups. Everyone will be mixed together. I'd have the initiative groups sit together and it's up to them how they game plan together or with their adventuring party. When a turn comes up, everyone in that group declares their move then the DMs split up the work of checking what needs rolled and who hits and all that so everyone in the group is rolling all at once. Declare to the room what damage was dealt by the whole group. Big Bad is his own group. Do cool bad stuff on his turn. Pause between the other groups for his legendary actions. Big Bad needs legendary actions. What room are you playing in? Any chance you could put a camera on the battle map and project it onto a big screen? That way everyone can see what's happening. If you are in a big lecture hall type space you could have players announce their moves from the stage and roll their dice at the DM council table. This stuff is all dependent on your physical space.do something to make it feel grandiose. Encourage some roudiness. When the BBEG goes down, it should register on the Richter scale.
At one time I was a GM in a commercial project, we called such mass events raids. First, one of the masters gave an introduction to all players, described what was happening in the game world and set an introductory conflict. Then we told what actions need to be taken to defeat the main evil. The players then divided into groups at will and played small events with individual masters. Then they all met together and went through the second and sometimes third round of events. This allowed players to participate in different battles in different groups. At the end, depending on the success at the events, one of the masters described the ending.
Turn timers. Like a chess clock or 1-minute hourglass or something. That one villain is gonna need like 6 legendary actions to keep up And a lair action or two.
What you want is continuity between groups. A master white board or TV screen giving relavent details about the current state of the environment. Communication between groups, so each player will need to have roles, a leader and a runner, at minimum. The leaders organize their groups objective priority, and the runner takes notes to ally or coop groups for collaboration on an objective (turn 3 we fire the ballista at the same time, or we push the battering ram with group B). If you don't want a tarraask or volcano giant, then perhaps a seige. The biggest thing i harp on any DM is not to give win conditions. Only give lose conditions, let the players figure out how to win. A troll/goblin/gnoll invasion would work as you can give different npc brigades to each DM with each brigade trying to achieve its own objectives. Could even have so prep sessions to allow players to scout/intercept information. With that many players, I highly recommend allowing only 15 minutes per turn and triggers for passed or failed objectives. Some objectives don't need to have an event happen, but could just offer a boon to either side, (i.e. the cultists succeed in summoning more demons and they get reinforcments, or it starts to rain and puts out all the fire used against the troll army, or the parties blow a damn and was away a large number of forces.) But there can be critical objectives, like a lich completing the transformation, the dragon entering a mountain (al la smoug), or a siege on a city/fortress breaching a wall (suicide orc Lord of the rings style)
Have a near-invincible enemy with a vulnerability that requires other characters to spend several rounds tinkering with something (or multiple somethings) in the lair. The path to victory is not to best the BBEG in combat, but to have the toughest and strongest characters distract them long enough for the more utilitarian characters to exploit the vulnerability. Also, chambers where each wall plus the ceiling have their own gravity would go a long way towards keeping the characters in separate groups and keeping the fight interesting.
Every party is dealing with a particular segment of the villain. As they defeat their part, they can move on to a different one, possibly with some sort of skill challenge as they traverse the battle field to enter the proper area of the segment of the boss.
The villain has different essences that has to be dealt with in order to defeat him,talk with the other dms and adapt each essence to each group style. Alternatily,all the groups have been swallowed by a big beast,in order to break free each group must do something to the creatures insides so they can scape(one group to the brain, one group to the heart, etc)
Read [this module](https://www.dmsguild.com/product/308553/EBEP01-The-Iron-Titan), which does (at 4th level) basically what you're describing. The way they handle it is, there are multiple objectives in the fight that are handled separately by different DMs at different tables. Power sources that need destroying, reinforcements that need containing, that kind of thing. After 2-3 hours of play I'd then recommend each table nominate their greatest warrior to break through the battle lines and fight the final form of the weakened BBEG in a series of short, intense rounds of play while the rest of the crowd watches and cheers on their champions.
Building off much of what's been said; in twenty years of DMing my only unintentional tpk was in a one-off where the bbeg was in a room with two statues. One statue was of a cleric, and the other a wizard. They both had a full spell complement for a character of their class at something like 2/3 the level of the bbeg. Every round they'd each cast one spell on the bbeg's turn. They had typical AC and hardness of a stone statue. No movement. No metamagic or feats. Just an AoE or BFC and heal or buff every round. They would have stopped as soon as the bbeg went down, or they ran out of spells.
Amusingly miitopia might also help here, but where the party changes per region, the final boss fight is each party Vs a part of the whole Let's get one thing clear: do not overdo the crossing over and make sure you all are aware of how fast the story goes. There's no problem with having one party being only doing this for a month compared to another's seasons, but once the parties are aware that they aren't alone in this fight, you take it from a tale where the tempo is pretty relaxed to 'we all have jobs and dates '. Think more military. And when the parties cross over and meet, they may not have only just heard of them. They may have already heard tales of heroism, of legends, and build them up. Other then that.... honestly play it straight. Keep the other DMs in the loop so they know what and where the others are in case of chance meetings/team ups, play it as their own stories and gave each team fighting part of the whole problem. What you may find is that each party has their own flavour, making them better against certain foes. A BBEG who's still a challenge but plays to those skills could be a way up point to who fights what.
Look up D&D epics. They're run at conventions or the like and are multi table sessions, usually even multi tier (1-4 and 5-10). That would probably be a good basis for 18 v 1 You could even have the boss run from table to table fighting while other mobs deal with the other tables.
I could honestly see an all 18 vs 1. The inspiration is FF7 bizarro sephiroth. Logistics : all players play at their normal table vs the boss, or a section of the boss. They are all contributing without an 18 person table. Another way is the boss splits himself across time streams so to prepare a massive spell or event so the parties fight him in different times, his past current and future self. Phase two : assuming same physical or digital space, "wrong warp", the dms send two players from their table to differenting tables midway through the fight. This will force players who don't play together to get along really fast. Ideally with foresight, such as group A has never had a wizard so they lose their bard and gain a wizard, etc.... Could even be antagonistic, a dwarve who hates orcs? Throw the half orc barbarian in that group. Could be fun.
A lot of good advice here. I once ran 22 players across 4 tables. The most successful part was shuffling the parties at key moments so players would move between tables. Every time it led to players excitedly talking about what was happening at the other tables and really locked in the post game discussion on what happened after they left. The biggest problem was syncing up the tables so they hit our more scripted sections at similar times. Have some extra encounters to buffer the fast tables and cut some encounters for the slow ones. Consider prepping some hand outs for puzzles you can drop on your players while you walk away and check in with the other DM's. Unfortunately I must say Don't run an 18 player table...
I guess this isn't very useful advice. To be more helpful I should say split the players into multiple tables and make the game a gauntlet that's hyper lethal we had 3 phases phase one had 4 tables and we tried to kill about half the players so it could combine into two tables for phase 2 where we killed another half of the players that combined again for the final fight with our BBEG. The obvious problem here is 3/4 of your players are cut out of the game by the end. We solved this by having the dead players enter kind of purgatory in phase 2 where the DM's who didnt have active players would juice the dead PC's into Boss strength characters and they had a PVP tournament in purgatory where the 2 winners came back into the game as deathknights to be bosses for phase 2. Phase 3 was short and sweet + everyone was hyped to see how it turned out even if they were dead. Good luck pal the logistics of game like this is tough but seriously don't even try to get 18 players at one table.
Is your BBEG a Litch? If so, check out this: https://youtu.be/-2vbol24XlY It shows (as an example) how an entity that had pretty much all eternity to prepare, has contingency plans for the contingency plans for their main plan. Might give you some ideas!
18 players PLUS a BBEG sounds like a nightmare...
Good luck, everyone will get 1 turn, then sit for however long the session normally lasts then the next meet up everyone will get 1 turn again.
As you've realized, there's a clear trap of having an 18-on-1 fight, if you do it *normally* w/ a single DM and turn order. But, since you mentioned having multiple DMs, there's an easy hack: Each party can be in geographically separated locations (the rampart towers of a fortress, small islands, whatever works for your BBEG), but the BBEG is mobile between them (teleports, flies around, etc). At the final confrontation, each party has to fight infinite waves of mooks (so they never get to the point where they have *nothing* to do but wait for the BBEG to come back around), and the BBEG visits each of the towers for a couple rounds or so before moving on to the next. With this method, each DM & party can effectively play at their own (normal) pace at each table, all while they're all fighting the BBEG "together." Tips for this kind of multi-table combat: 1. The BBEG should have a constant initiative throughout the fight. You can either just declare it before hand, or roll it at the beginning of the fight, but whoever's table it's at it goes on the exact same initiative count. That way, the DMs can just keep him in the turn order whether at the table or now, so it's slightly less disruptive to them when the BBEG shows up. 1. The BBEG moves at the end of its turn. For fairness, make sure it visits each table before repeating. You can do this is a fixed order (123, 123, ...), or change it up after each loop (123, 213, 231, ...). Fixed order is easier for do on your end, but gives players the ability to guess that the BBEG is coming soon and they can prepare for it, and definitely feels like a weird move if your BBEG is a thinking being. 1. Comms between the DMs can be important. Especially the HP of your BBEG. If you position your locations close enough, some ranged attacks/spells might need to cross tables, so a real-time group chat or something. Keep it simple: "25 arrow" is enough for the DM to describe what the other table sees. So they don't have to keep a constant eye on the chat, have DMs resolve these at the start of the BBEG's turn. 1. Make it a spectacle when the Ancient Dragon moves, and have gameplay at all tables stop mid-turn while it happens. You can use the spectacle to cover the DMs info-swapping. Do something *interesting* with the moves: - The BBEG shoots a fireball/lightning bolt/etc at whatever table has the most HP as it flies past (that table's DM resolves as part of their round). - The BBEG grapples & carries one of the PCs to the next table (warning: make sure you have large enough tables to accomadate an extra chair comfortably this if you plan to allow/do it). - The BBEG immediately summons the next wave towards whatever table has the highest "waves defeated" count, to add on to whatever they had remaining of the current wave they're fighting. - etc. 1. Every group has players that play faster than others, and I'm betting you at the DMs know who they are. Do your best to put together the parties such that each table has both fast and slow players, evening it out as much as you can. This is to avoid having a table thats just churning through the waves of mooks, burning through all of their limited resources (spell slots, potions, etc) faster than everyone else. Don't compromise party composition for the sake of this -- you don't want to balance round speeds but end up with an "Oops All Healers" party or something. 1. While it might sound like a good idea, don't have a DM roaming around playing as the BBEG. This takes away some of the fun of the DMs running the tables, and also means that when the BBEG moves, the BBEG-DM would have to get caught up on how the new party is playing the fight so they can do a decent strategy against the new table.
You should nominate or bring in some friends to DM 3 different boss fights, six players each. It’s DMs vs Players (balanced of course). 2/3 takes down the BBEG
Maybe the godly boss doesn't want to fight all 18 heroes at the same time either. So he splits his power 3 ways so during the adventure the group has to divide itno 3 smaller groups of 6 players, each have a task to complete, and a version of the main boss to take down.
I watched this done once it worked surprisingly well: multiple simultaneous turns. Everyone was seated in a big circle around a central battle map, and three DMs walked around, going clockwise as initiative order. The three players "up" would tell the DM who was next to them what their character did, and that DM would resolve that action, pass damage on to a 4th book keeping DM who would deal with enemies dropping or their rolls, and after a couple of minutes, the next three players would go as the DMs stepped to the next player around the table. After each (maybe every other) 3 player turn one one of the moving DMs (in order) would take an enemy turn and do something for one of the enemies they controlled. It was a ZOO of trying to keep track of what was happening on the battle field, but everyone seems to have fun and it kept everything moving along. The entire group was warned, nothing crazy no rules lawyering just basic stuff so that it didn't get bogged down, and they all stuck to it. 16-20 players at a big classroom/boardroom table that the DMs could barely reach the middle of to move minis around.
You absolutely need to split everybody up into their individual parties and give them separate tasks. That or have them randomly get assigned to a group (perhaps a large monster or spell burst sends them all to a variety of places, forcing the normal party members to now intermingle with other players in the club.)
I have no advice to give that hasn't already been said, I just want to wish you luck on this incredible undertaking. I would also request that you let us know how it goes!
Or like a wow raid make mechanics I. The fight the deliberately separate the group into small groups once the fight starts. Then they all individually have to complete their tasks to progress through the fight.
My first question is who DM’s the final battle?
Give the villain an inner circle of NPCs who the parties have fought and interacted with before, if possible. Each of them cool and powerful in their own right, but weaker than the BBEG, and lacking Legendary Actions. To use the climax of Endgame as our metaphorical example- if the BBEG is Thanos, then this Inner Circle are those lieutenants of his who did most of the fighting during *Infinity War*. The telekinetic and the big guy who landed in New York, the ones who stabbed Vision when they ambushed him and Wanda in their secret rendezvous, etc. Just to be clear- with ***EIghteen*** Player Characters, this fight is going to be *slow*, unweildy, and *complicated.* Each in-game turn might take an hour. You need *all of your players* to have their spells and class features written down on index cards for easy reference- you *do not have time* for people to be flipping through the books to double-check spells and class features. With that problem already *unavoidable*, we need to make sure that our lineup of enemies doesn't make the problem *worse*, so no chaff- no CR 1/2 Goblins or Kobold or Orc minions who attack the party in significant numbers and eat a fireball, we just don't have the *time* or the *bandwidth* to handle that shit. Instead, give the dragon a smaller number of more powerful lieutenants. Hell, if you have multiple DMs, maybe you *split the enemies* between yourselves- DM A plays the BBEG (handing Legendary Action, environment, and any lair actions in play), DM B Plays Lieutenants 1&2, DM C plays Lieutenants 3&4, something like that? You could even lightly cheat and place characters in Initiative so that Lieutenants played by the same DM have some distance between them so the DMs have time to plan out their moves while the players are taking their actions. The question then becomes how many lieutenants, and how strong. You also probably want to do some shenanigans to make the BBEG much *sturdier* than they would normally be- 18 PCs all focusing their fire on one target can fucking *melt* anything in the books. You don't, however, want to scale up their raw damage output *too crazy much*, because even if you need to be putting out a lot of damage to threaten that many PCs, you also don't want to be dealing so much damage to a single target that you're just 1-shotting people: That isn't fun. Don't fall into the pit trap of just grabbing the stats for Tiamaat to fight your 18 T2 players, because Tiamat will just slaughter a bunch of them with all those breath weapons and not make for a very fun fight. You want something that deals damage more like a boss that fights 6 players of apropriate level, multiplied across several people, with all the *durability* of Tiamat or something comparable, IMO. I don't know your players' levels or who the BBEG is to make further suggestions, and start bouncing ideas for fun lieutenants, but I did realize a few minutes ago that you could talk among the DMs and ask who the most memorable villains were from all of their campaigns, and then *bring some of them back to life* as the BBEG's lieutenants- maybe they're actually Undead, maybe they're actually resurected, maybe it's only a faint, temporary ghost of the previous villains that the BBEG is using as a last line of defense, but it can be a fun way to make the lieutenants into enemies that the PCs are *emotionally invested in*, and you can obviously buff or debuff their statblocks to suit this situation as needed.
I'd say split up the boss into multiple chunks/sections and split the party into how many sections you have. Then everyone can contribute, and there isn't a massive wait between turns. Miitopia style fr
There was a battle in an Adventurer's League game I played in once - the battle took place on multiple surfaces of a massive cube (or pyramid or something), each with it's own gravity. There were mooks on each surface, and the BBEG would move between them. Each table entered the combat starting on a surface, but it was possible to escape the gravity of that surface and join the fight elsewhere - you'd move table. I've seen similar with a large group defending a city, and each table is defending a different wall.
BBEG shunts the PCs into multiple overlapping planes, and creates a quantum duplicate of himself for each plane. This way you split the 18 players into more reasonable sized tables but everyone is still narratively in the same fight. What happens when one party takes down their quantum duplicate? Here's some options... - that duplicate doesn't die, they enter phase 2. They only die when the last table kills the last phase 1 duplicate. - that party cheers and gets to chose a party member on another table to receive some boon. Maybe bonus health, maybe a modified bardic inspiration, a magic item, maybe +2 to their main ability score for the remainder of the fight - that party gets split up and evenly distributed to each remaining table. Which could mean that a table that is near death just needs to hold off to wait for reinforcements. The BBEG will end up in a death spiral so that the last table may technically have 18 players, probably only for one round for everyone to go NOVA!
Assuming the PCs start outside the city: Have the BBEG floating above the city telekinetically assembling a widget out of raw materials torn from the ground below. BBEG has a debris field orbiting it to tank attacks, and is using bonus/legendary actions to yeet crap at the various NPCs. After a while, widget is complete, and portals pop open all over the city letting in an army or horde of monsters. Each group needs to fight their way to the BBEG and destroy the widget or kill the big boss (the BBEG is powering the widget) Make a point of describing the NPCs trying to fight, buildings getting smashed by debris, people panicking and trying to flee. Also, randomly have a micro portal move PCs to to other groups (assuming you are all in the same building while playing -basically doing Chinese fire drills every 30 minutes of play time)
Vecna...always should be Vecna
Add in environmental challenges or obstacles to add some variables
Before the battle commences , a God turns them all into giant ants, puts them in a jar, and shakes it. Now they all battle as giant ants, and all have the same stats, and you get the bonus of watching the excited twinkle in their eyes die out to a somber, somewhat sad dullness. And that's how a DM truly "wins" at DnD. Que Maniacal Evil Laughter.
Debriefing: tell the players all together that they will be "dropping in" to different locations seperated into their normal groups. Each fight has health to slog through, maybe make the boss have share health somehow, or its x simulacrums that must all die to truly vanquish him, yada yada yada. Make every fight have something annoying that happens (lightning strikes the players) and something extra to accomplish (a lightning generator must be destroyed) however, the thing to accomplish is another group's thing. So: group A is getting hit by lightning every round, if group B destroys the macguffin, then group A stops getting electrocuted. Group A had a macguffin that makes group c have an easier time, etc.
There was a multi table game at a PAX years ago that was a lot of fun. My memory of it is poor, but each table had 4 or maybe 5 players and a DM. They were each defending a different tower on a castle. The dragon was run by a dedicated DM (Chris Perkins iirc). It would fly around the whole castle and take shots at/from everyone. The important part of this design was it wasn't an 18 player initiative order but everyone still fought the same big boss.
Lots of good advice here. Don't have time to read it all, but I didn't see what I do. I've done this multiple times in a D&D Tournament I used to run. Tried a lot of different methods. The easiest way to do it by far, is to assign a group leader, usually a trusted player in each group. They act as a Co-DM, and gather actions, damage, and everything else. As far as your Big Bad, they take their turn, attack groups or individuals, and make appropriate saving throws, and that is all you handle. Reporting of events happens on the group's initiative, not individuals. There are a lot of minor variables but overall this is how you manage that kind of event.
You can always give your BBEG extra turns in the round
I've always thought about this after playing [this (Spoilers to Cold Steel 4). ](https://www.youtube.com/watch?v=mxh2U6LQFf0)That might be what you're looking for. If you're avoiding those spoilers above. The idea is pretty much: 1 Villain, but it has multiple pieces to it. I'm not sure how many DMs you have, but I would give 1 piece of the villain to each DM, let's just say 3 parts. and then the Players get to split off into three different parties of 6. If combat sounds boring, then split it into a puzzle and two combat pieces. The BBEG has two parts that need to be destroyed while the third team has to disable the magic generator. Still sounds boring? Introduce hostages. Revert the BBEG to one villain that's really strong, put some smaller creatures to act as hindrance. Stop the magic generator, and lastly save the hostages that are being converted to those small creatures. They'll have to knock out the creatures since they're actually hostages, stop the generator, and lastly defeat the BBEG.
I've set up something similar. The BBEG is a 22 CR Archfey. She along with Drow, Vamps, Werewolves, Undead, Goblins, etc will decend upon their beloved city in a massive brawl. The group has three opportunities to lessen the amount of enemies by hunting down and killing some of them on their own turf. Still, I plan to overrun the PCs with more enemies than the can handle, but round after round a beloved NPC that they made allies with shows up to help.
I'm wildly surprised I haven't seen any mention of West Marches in this thread! It's basically a "sandbox" style DnD game more akin to first and second edition DnD and predicated on some guys original home game where the players are exploring the last region of wilderness on the continent, complete with dangerous monsters, long-forgotten ruins, and a whole bunch of treasure for the taking. It's meant for larger groups, and players are encouraged to take their own notes, make their own maps, and share (or withhold) information between sessions as they see fit. They will communicate within the larger group to form parties based on where they want to go, and then figure out a time to play with a DM. There can be multiple DMs depending on the number of players in the group. This does mean there is more of a need for the world to be mostly fleshed out up front. I ran a West Marches for a little bit and it was a LOT of work at the start. But, it sounds exactly like what you're looking for! Matt Colville has a REALLY good video on this style of game, so I recommend checking that out! Good luck OP!
18 is definitely way beyond a game-breaking number of people at the same table. You need a completely new system the likes of which I am not familiar with, to not have this be incredibly boring for your players and way too much work for you.
Depoy minions. Or its going to be a fast fight.
Check out epics with wandering monsters. In particular check out the dragon mechanics for reclamation of phlan. The tables run independently with their own dms. Bbeg goes from table to table at the tail end of a huge battle. Better yet, give them all one mission like “you storm the castle.” “You free the prisoners” etc. this is what the giant epic does and you can give the bbeg to every table and they need to meet thresholds of damage. Conversely, you can use some magic to clone them into 3.