21 TRAPPED CHAMBER. The walls, floor, and ceiling of this room are different from the others in the vicinity.
The floors and walls are made of stone tiles. The bizarre ceiling is decorated by hundreds of stone devil-like faces in alto-relief ranging from fist-sized to up to three feet in diameter. As the party crosses the room, each party member has a 15% chance of stepping on a pressure plate that will activate the trap.
Should the trap activate, the doors will auto-lock, forcing the party to stay in the room until one of the locks are picked, the doors are magically opened, or the doors are smashed down. The faces will begin telescoping down to strike the adventurers. The devil faces are mechanical in nature and come crashing down randomly. Each character must save versus petrification each round that they are stuck in the room or suffer 3d4 points of damage.
Once all individuals have exited the room or have been killed, the devil-faces will return to temporary passivity. If the room is visited again, there is a 50% chance that any damaged portions, such as a broken door, will have been repaired.