Level 13 Lurker
XP 800

A disruption of some sort sets off a chain reaction that doesn’t end until all the room is covered in rubble.

Hazard: When triggered, rocks and debris fall from above to fill the area with attacks. It attacks a different part of the area each turn, on its initiative.Perception     DC 31: The character sees that the ceiling appears unstable.Dungeoneering     DC 26: Same as for Perception, above.Initiative +6TriggerThe trigger for a cave-in can be random, caused by the actions of others, or timed. When triggered, the cavein rolls initiative. Between the trigger and the cave-in’s attack, characters in the area know that a cave-in is beginning. On its turn, the cave-in attacks a random square within the encounter area.AttackStandard Action      Close burst 1
Targets All creatures in burstAttack: +16 vs. ReflexHit: 2d12 + 8 damageMiss: Half damage.Effect The burst area becomes difficult terrain.Sustain Standard The cave-in attacks each round, targeting a different square.Countermeasures     Dungeoneering DC 31: A character who makes a successful check as a minor action can determine the square the trap will attack on its next turn.

Published in Dungeon Master's Guide, page(s) 91, Dungeon Magazine 157, page(s) 71, Dungeon Magazine 161, page(s) 49.