Large scale battles in Dungeons & Dragons can be a bugger to do. With how action economy, level balance, challenge ratings, etc, it can be a lot to consider. But here is the thing, the overall goal of the game is to have fun and as the Dungeon Master you can fudge the hell out of your rolls. This is how I had nine level 2 characters and a level 15 NPC take on 80+ goblins and a few measly demons…
The villains of this adventure were a collection of cave goblins. Cave goblins are a specific breed of goblin detailed in Nord Games’ Ultimate Bestiary: Revenge of the Horde, an utterly fantastic book with extended versions of some of the classic humanoid villains (orcs, gnolls, kobols, and my favorite, hobgoblins). Cave goblins are unique to goblin-kind in that they form a sort of collective intelligence, where they act synchronized making them more threatening. This intelligence declines with their numbers as well as the inverse. They ultimately are all controlled by a cave goblin king. The players dubbed him the “Sovereign.” Why this is the case is open for interpretation in the book: psychic connection, pheromones, but something is at play. Regardless, they made a perfect opening threat to the players!
The board used had a base of some faux grey leather, then to make the lost ruined dwarven streets I used a combination of the 3D D&D Dungeon Tiles “Harrowing Halls”, some OpenForge 2.0 items I printed, a few pieces of dungeon decor from WizKids’ D&D and Pathfinder miniatures, and a handful of rocks from my yard. This setup was very open looking, but I managed to get the players to understand the claustrophobia of the area by using a series of pillars in the center. A feature I also included were a series of grates: some closed, some pried open. I had the players notice they were loose, but heavy along with noises coming from below. They were a way for them to move around the street without notice, but were to be infested with some left over minor demons; a maw demon and a handful of dretches. Sadly, they did not use these until towards the end of the fight.
So how to manage so many monsters? Minimally. As much as I complain about 4E, it did one thing right: minions. Effectively I did not keep track of goblin hit points except for the few brutes and the “Sovereign,” who got away! But all the other goblins, if they got smacked they went down. The heroes felt triumphant and made ample use of the 3d terrain. The archer even took high ground to get better shots, having to resort to her short swords when swarmed by goblins!
Huge role-playing and social encounter with Baern afterwards. I did not want to drag the caves out anymore; got the players above ground and back to Fort Thunderknuckle. Baern briefed them and discussed a variety of things that all would go down in session 4.