The first campaign I ever ran started with six players, made its way down to four, and eventually settled at five with one more who’d play once every couple months. The second one had eight. The third one had almost a dozen, but only about six-to-eight ever made it to a session at any given time (it was specifically built for this). My main Dungeons and Dragons group in Madison was six players for a while, but then it shot up to eight and now sits nine after a couple years of jumping around. The campaign I currently run the most frequently, “Broken Worlds,” has three players. I’ve run a campaign for two people, and even ran a one-day campaign for a single player while introducing them to D&D. While a specific idea of a “basic party” exists for D&D, which is what the D&D rules expect when it comes to assessing difficult or setting up appropriate encounters, I have rarely had four players in my group and the party has almost never been “balanced.”
As I’ve said before, a good GM can find a way for any party composition to work, but what could bear saying is that even a good GM can’t always make any size party work. I know a lot of GMs who thrive in that four-to-ten player range, but who absolutely struggle to make the game work for fewer than four. I know a couple GMs who can’t handle more than four or five, but almost prefer the super small groups of one-to-three players. Personally, I struggle with anything over seven players, but can easily handle anything up to that point. What usually gets me is trying to manage combat and player engagement for eight of more people. There’s just so much to keep track of that I often can’t keep the turns going so my players can stay focused or I keep needing to pull people aside so they do their little solo mission because they feel like they’re getting lost in the crowd and thus start doing things alone to force their character to stand out. The latter is a slippery slope if people start doing it for unnecessary stuff, since it usually means more people start to feel like they’re not getting enough of a chance to act so they start doing solo stuff as well and then you might as well be running several small D&D sessions instead of one larger one.
To be entirely fair, that can be a way to manage a large group. If you know there’s a stealth section coming up that the Ranger, Rogue, and Bard want to do without the noisy Fighter, Cleric, Wizard, and Paladin following then around, call a separate session just for the sneaky people. Even if the non-sneaky people are waiting outside to start busting down the gate in the case of an alarm, you can always run the sneaky-people along until they either set off the alarm or finish with whatever mission they’re on. If they set off the alarm, mark down where they are and say you’ll pick it up when everyone is around.
Another thing you can do for player engagement is handle down-time adventures via some text format. There are plenty of forums that are set up for this kind of thing or you can just do it all via email. Heck, you could even do it via text message between sessions. Or set up a session day as half-hour increments of time people can come to you to do whatever they want when they’re in town. That way, they can include other members of the party in decisions or little role-playing moments just by going into the next room and asking for an answer or whatever. Anything works, so long as it’s happening outside of the actual session. This way, the time you’re all together to play is when your party is all together and everything that’d slow your group down is handle at another time.
For combat, managing large groups is trickier. You can tell everyone to have their actions figured out and establish a turn timer, but the longest turns are usually the GM’s turns (well, the turns taken by whatever it is the players are fighting). Because everything in D&D is set up for an optimal four-person group, doubling that number of players can mean that some encounters that should be challenging just aren’t. With a large group, few GMs have their players fight against a single tough monster. Instead, they’ll have them fight more, but slightly smaller, things. Or, as is more common, a huge number of much smaller things instead of the large number of medium things. Here, it gets tricky. If your players are all fighting the same thing, that makes it a little bit easier, but that’s rarely the case. Usually they’re fighting a variety of smaller hings so it’s not all spear-chuckers or sword-swingers or spellcasters. Sure, you can save time by making everything that’s the same move or act at the same time, but that’s still a lot of moving, acting, and rolling you need to do. All of which needs to happen in addition to managing the players are they react to what is going on and need questions answered. The only real solution I’ve come up to this–aside from having super patient and understand players–is to have a second GM step in.
While that might seem difficult, it usually isn’t. All you really need is a knowledgeable player or someone who you can trust to avoid meta-gaming. If they’re knowledgeable, instruct them to handle player questions about the situation and you likely won’t even need to show them your notes. If you can trust them to avoid meta-gaming, have them play the parts of some (or all) of the enemies. If you get another GM to sit in on your session, then you don’t even need to worry about everything else. Just give them the enemies for the party to fight and make sure you set a reasonable expectation for the other GM on how you’d like the fight handled. If you trust them to mesh well with your game, you might even be able to get them to not only run the enemies, but also create them in the first place. They’ll probably want a little more autonomy then, but that’s not a problem if you trust them to carry your intentions into their monster/enemy creation.
After that, the only real problem you have for large groups is how to keep everyone playing in a friendly manner and where you can get enough seating. I suggest folding chairs and regular potlucks. Can’t hate someone if they feed you regularly. Though, to be fair, this is less likely to be a problem than anything else since GMs should be good at monitoring groups and understanding which people will play together. You’re unlikely to need to deal with inter-player conflict for long, though, since people tend to just leave. Good luck with your big groups and let me know if you’ve encounter similar problems before!