Monsters that exist in groups are currently completely individualistic and try nothing more complex than charging towards the player and hitting in melee once they get there. This makes it easy for the player to cheese what would otherwise be tough battles, e.g. by standing in a doorway and killing them one by one, or by kiting them. There are some proposals for smarter AI:

• If a single monster in a group is next to the player, try to pull back until allies can get next to the player.
• Avoid doorways and narrow corridors; if you are in an open space, stay there unless you decide to move to another open space, and hang back from the doorway where the hero is, forcing them to enter the room in order to pass.
• Groups of intelligent monsters also try to stay out of the way of ranged fire if possible.
• If the current strategy is to defend a certain area, form ranks to block the player from reaching it.
• Pincer maneuvers; some monsters of a group will split up and try to get behind the hero or attack from another side. If the pincering group hasn’t gotten in position yet, the other group will fall back until they catch up.
• Wolf pack: the monster of the class with the highest level, or failing that the highest max HP, “leads” the pack, and all other members key in on this leader and follow it. This means if you get the leader to flee, the rest of the pack will flee as well.
• The Yendorian Army can form a phalanx, which is an ordered rectangle of soldiers. Will stick to wide open areas, try to stay out of the range of ranged attacks until they can swarm around you. Enemies forming a phalanx could receive to-hit and AC boosts.