In zm_lila_panic_l_v3, the spot in the vent I know it not illegal since it is connected to the room beside it and still allows zombies to enter that room. The thing I can see being an issue is when the humans occupy that room and are defending it successfully and there are other humans in the vent camping, could you consider that illegal? With the room blocked off, the ones in the vent only have to watch the vent entrances. But, when the humans in the room become zombies themselves the vent would be considered legal. This way it balances out so that both humans don't have to worry about being in an illegal spot and the zombies have and equal chance at tagging them. Edit: Just to clarify, the area that I marked out is the wall you need to break in order to have access to the room from the vent and vice versa.