As your dungeon becomes more advanced, you'll start attracting more powerful creatures. Unfortunately, a great many of these do not, and will not, get along. The majority of conflicts between your minions will take place in the lair - natural enemies don't want to bunk together. The only real solution to this problem is to create a mini-dungeon made up of smaller versions of the necessary rooms - and as far away as possible from like rooms. Build a small lair, hatchery, and training room, then grab any troublesome creatures (Vampires, Horned Reapers, and spiders are the worst culprits) and drop them in the new lair. If you're really worried about keeping your minions away from their enemies, use a locked door on mini-dungeons to keep the critters from wandering your hallways (just make sure you unlock it come payday).

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