Delta’s D&D Blogspot has posted a session summary of Saturday’s expedition into Dwimmermount. He notes:
Tavis may have more courage than I do, because he had something of an open call out to players, and once we had dinner, piled into the Brooklyn Strategist, and set up to play around the custom gaming table there, he had no less than nine players ready for the session… About the first thing that Tavis said to me was, “You can have 4 henchmen, does that appeal to you?” Does it!? (I’m semi-infamous for gleefully playing multiple characters. Here I would get to play a whole crew of 5 dwarven plate-armored fighters. This was a very good sign.) With similar rulings around the table, we had a total of eighteen characters assembled and marching up to Dwimmermount.

I'm glad Stefan insisted that we actually put all the miniatures into the layout; the work he put into wrangling them was well worth the visceral sense we got of just how insanely stretched-out our marching order was.
This weekend there is indeed an open call for players at the Dwimmermount sessions I will be running on the evenings of both Saturday 3/17 and Sunday 3/18. After that, the expeditions will continue every Saturday until 4/14, but I will be passing my spot at the big Sultan gaming table on to other GMs.
I am famous for running groups of up to 15 players, but normally those are shambolic affairs in which we are glad to spend six or eight hours chatting and chewing the scenery and not getting much done. The Dwarven Forge scenery we have at the Brooklyn Strategist is so appealing that it begs out to be played with right now, so I evolved a way to get this big group moving faster than I normally do. I hope this house rule will be useful to those who come after me.
Because we were using the Adventurer Conqueror King System, when combat occured I would ask everyone to roll for initiative at the start of each round by holding up a d6. This part is standard, and with the possible exception of the kobold massacre, each of the fights on Saturday was sufficiently complicated and high-stakes to make it worth paying close attention to who got to go before the monster(s) and who didn’t.
When we weren’t in combat and the next course of action wasn’t obvious – basically whenever the flow of action seemed to pause a little as people wondered what to do – I would hold up a d20 and ask everyone to “roll for the caller”. (Actually I said “roll for initiative” here too but that led to confusion. Do as I say, not as I did.) Only the high roll counted, so once I heard a pretty high number I’d say “OK, can anyone beat an 18?” I didn’t have the players modify the dice roll by anything, so that all participants had an equal chance of winning. I don’t think it makes sense to have charisma modify the roll – this is a procedure for the players, not their characters – but it might be interesting to keep track of how many times this call for callers had been issued, and tell everyone who had not yet been a caller to add that number to their roll.
Once a high roller had been established, I would find a way to describe the scene to explain why that player’s character now found him or herself in a position to set the next course of action for the party. The first time I called for a roll was in town as soon as everyone had a character sheet ready. Stefan and Peter tied with an 18, so I said “OK, Father Roy and Dewdrop Morningwood, you were the survivors of the previous expedition. As you’ve been here in the Fortress of Muntsberg healing and re-equipping, you become aware that news of your exploits has brought a new crop of adventurers who are looking to repeat your success. Do you want to lead them to the dungeon right away, or spend more time in town seeking out special equipment or pursuing the truth behind some of these rumors?”
It was intentionally implicit in this setup that all the new and old characters would form a party together, but I think Pete picked up that it was not actually covered by anything we’d roleplayed, so he had Dewdrop’s henchman Lafonte Shimmersky give an elaborate recruiting/motivational speech, and then Stefan and Pete read the mood of the group and decided to head for the dungeon right away. (This was what I thought everyone wanted, and also what I wanted myself – all that Dwarven Forge terrain begged to be marched upon – so the caller procedure worked!)
At the top of the landing, we rolled for caller again and the dice chose Miguel. His character was a prestidigitator named Obed Marsh, so I said “As the group reaches the head of the stairs and the metal Thulian doors, a feeling of eeriness settles over the party and they unconsciously look to Obed for his expertise in arcane matters. How do you direct your fellow adventurers?” Miguel chose to have his characters take the lead and investigate the situation, asking questions that let me feed the group information. But just as you can see in historical accounts of parties using callers like the example of play in the AD&D Dungeon Master’s Guide, the caller was the decision-maker but not necessarily the spotlight player. Other players might speak up to contribute – when Obed learned that the mountain was protected from tunneling by some kind of enchantment, Dan said “My dwarves put away their axes and picks, disappointed that their plan is shot” – and sometimes the caller would designate another character to perform a task, whose player would then take the spotlight (for example, Carl’s thief who led the exploration of the rockfall that exposed the gorgon cave).
I felt like this procedure worked very well for speeding up decision making by giving the power to the dice. As the Judge, I didn’t have to think “how can I get the players to start moving and stop debating; I only had to recognize when it was time to call for a roll, and then hand off the problem to the randomly appointed caller. A key part of the method was to set up the caller’s authority by setting the scene for their character. By describing to everyone how and why Obed had emerged as the leaders for the other characters, I was encouraging everyone to start thinking in character as well, which thus included accepting that their character was going to be regarding the caller as the natural leader for the moment.
I think the caller procedure would work even for smaller parties. If you try it out in your games, let me know how it goes!
What People Say to the Mule