Our other regular Dungeon Masters and subs were unable to make the library "old school D&D" session the other night so I ended up running a 2.5 hour game for 20 players at my table. Thankfully, I knew ahead of time that I was going to be solo so I was able to prepare something appropriate, and the system we’re using — the 1981 Basic/Expert D&D rules, excellently restated in Old School Essentials — is arguably better-suited for a group that size than nearly any other version of the game.
The adventure went as follows: The PCs, members of a “delving company” occasionally mustered for military operations, were given a mission to clear a small island of a hostile force of lizardmen and human barbarians, said to be holed up on the grounds of a ruined temple. The route to the site was straightforward: a mildly perilous boat journey and short overland trek. Once there, a Thief PC’s early scouting attempt failed awesomely (and hilariously), leading to a frenzied charge by the group and a pitched battle with 60+ combatants. Four characters perished in the melee (including one at the hands of a fellow PC struck by magical confusion) and several others were knocked out. The party proved victorious in the end and came out with a considerable haul of treasure and some nice magic items.
The game was intense, a little chaotic, and a lot of fun for all — even for me, the referee. Here are a few things that helped me from feeling overwhelmed and greatly lent to the session’s success:
Keep things open. Spatially, in-game, that is. Dungeon delving in spaces with ten-foot wide hallways and lots of small rooms can be really tough on a large group of players. If there’s an encounter in one of these hallways, and only the first rank of two or three fighter-types (and maybe the second rank if they have spears or polearms) can effectively engage, what’s everyone else going to do? Placing all the action outdoors meant that there was a lot more room for player characters to move about and effectively use various skills, spells, magic items, and tactics.
Keep things simple. The goal of my adventure was very simple: defeat the enemy force. I had a couple of potential random monster encounters for getting to the ruined temple (only used one) and one big set piece — a potentially huge battle that, between PC planning and execution, would likely take up most or all of the session. I did have an under-temple level semi-prepared in case the main event finished early and PCs still wanted to explore, but ended up not having to use it. When it came to the enemy group, it was up to the players to decide whether they were going to pursue diplomacy or violence — negotiation was briefly considered, but they chose the latter (as adventurers often do!) There were a few short, focused bursts of lively discussion about direction of approach, scouting, and tactics throughout the first half of the session; much to my pleasant surprise, the players made decisions fairly quickly so the pace didn’t flag much.
Keep things moving. There’s much more to be said about choosing appropriate rulesets for different types of library games in another post, for now I’ll just say this: one of the great advantages of using OSE/BXD&D at larger tables is the simplicity and speed of combat. With a little bit of preparation and a few simple techniques, it can go even faster.
Prep your PC roster. At the beginning of each session (regardless of how many players), write the players’/characters’ names on a numbered list. I do it on a big whiteboard easel so everyone can see. During combat, mark a little “m” next to those who engage in melee (and erase if they disengage)
Use a Caller. In early versions of D&D, larger player groups were assumed to be common. To help the DM manage the game, the authors suggested the players elect a Caller, who helps to direct their strategizing and convey the party’s decisions to the DM. Using one Caller in my game the other night was extremely helpful; given the physical size of the large table (and the great distance between people at each end), it might have even been better to use two Callers, one for each end.
Declare actions. At the beginning of each round, players who are casting spells or disengaging from melee declare what they’re doing before initiative is rolled. For those doing melee or missile attacks, I just get a show of hands for each. This has the benefit of making players commit to their plans, which in turn negates the on-the-fly tactical discussions that can crop up mid-round and potentially bring the action to a standstill. (I’m a recent convert to pre-initiative declarations, having ignored them for most of my gaming life. What a difference it makes!)
Players roll simultaneously. I tell the players the Armor Class of the monsters they’re fighting, and they have the to-hit AC matrix already filled out on their character sheets. With those details out of the way, I can have all the players doing missile fire roll, then go around the table and get damage numbers. Same thing for melee, then all that’s left is to adjudicate spell effects.
Referee rolls fistfuls of dice. OK, maybe “fistfuls” is an exaggeration, but I’ve long been in the habit of rolling multiple dice simultaneously for monster attacks. For a single monster, I’ll roll its attack die (or dice, if multiple attacks) and, often, a separate die to determine the target. [20 PCs? Roll a d20 and refer back to the handy numbered list of players. Only 12 are marked as being in melee? Roll a d12 instead. 9? 1d10, re-roll 0’s. You get the idea.] With this technique and multiple sets of dice in different colors, I can use 4d20 and 4dX to greatly speed up attack rolls for the horde of unremarkable lizardmen warriors, barbarians, archers, etc.
A variation on this, if the monster has a chosen or fixed target, is to roll the attack and (potential) damage dice simultaneously.
As an aside, when I run games I always roll attack and damage dice in the open so players near me can see the results. This helps the players know that the game is on the level and the referee is (in that sense at least) a “neutral arbiter,” and if someone’s character gets killed by a critical hit there are witnesses to that “20” and maximum damage rolled!
What’s the biggest group you’ve refereed at your table? How did it go? What did you find particularly challenging? What strategies have you used to make large-group games successful?
I've never had to manage twenty players, but it might work for combat and exploration to have players sit at tables that correspond to the roles of their characters for that scene.
Slightly analogous to a tiered-reference desk, where the librarian is on-call for research-related queries only, and a non-librarian deals with directional, printing, and other non-research-related concerns.
Combat example: melee combatants at one table, archers at another, spell casters at another, healers at another, with a caller for each table. If there are too many of any one role to fit at a table (for example ten melee combatants), they could split into two tables, each with it's own caller (like two separate squads).
Exploration example (roles for each table): checking for mechanical traps; torch bearers; archers on alert for ambushes (with readied actions); melee combatants ready with weapon in hand. Again with one caller per table.
In either case (combat or exploration) there would be three or four callers, each managing their own table to announce intentions and to help the DM resolve damage, spell effects, keep track of conditions like paralysis, fear, etc., so that the DM wouldn't have to keep track of each player. In this case the callers or other member of each table could support the DM with the whiteboard or other tracking system.
Something similar, that I have experienced as a player at conventions, is multi-table games where there is a DM at each table, and they occasionally confer together or report to a Head DM who is keeping track of the overall progress of each group.
Example A: Two groups of adventurers enter a dungeon simultaneously through separate entrances (two tables, two DMs, they confer, no Head DM).
Example B: Adventurers organized by level (1-3, 4-6, 7-9, 10-12, 13-15) each engaging in level-appropriate encounters to complete interconnected goals (five tables, five DMs, plus one Head DM (to rule them all), possibly a timekeeper (to in the darkness time them), and maybe even one or two runners to message between DMs).
Group messages can also be sent to each table via cellphone to indicate something has occurred simultaneously for each table, like suddenly there is an earthquake in the dungeon because the stone golem dragon has awoken. For example: in the 4e days, Wizards' D&D "Encounters" organized play system used "Twitter Buffs" during scheduled sessions that were played internationally (I think Paizo used the same approach at that time).