Type magical; Perception DC 35; Disable Device DC 35
Trigger location; Reset none
Effect Atk +24 melee (instadeath); multiple targets (all targets in a 10-ft. line)
Hidden in the soil of the The Dig are several glitched boulders. When a tunnel is created underneath one it hovers briefly before falling, killing anything underneath it. Sometimes these natural traps can be unearthed by the vibrations caused by excessive movement. During combat there is a 10% chance that a glitched boulder falls into a tunnel within The Dig. It hangs in the air for one round before falling, instantly killing any creature it strikes.
If the glitched boulder strikes a monster that has taken damage in the previous 1d4 rounds, however, all monsters on the level are instantly killed and the miniworld that the PCs are on becomes stuck; they are unable to progress until they return to the surface and allow the miniworld to reset (over a period of 6+2d4 hours hours). A monster otherwise killed by a glitched boulder is destroyed and the party may progress normally.