Lightning Doors
Trap
Level 13 Obstacle
XP 800

A burst of blinding lightning flashes from the doors, searing all in its path.

Trap: This trap covers the 15 squares (3 x 5) before the doors, threatening any creature within the area with a strike of lightning.Perception     DC 18: The character recognizes these doors as the same ones portrayed in the tapestry at location 12.Arcana     DC 23: The character notices various arcane runes in the door’s design.Trigger       When a character attempts to open or unlock the door (including using the key from location 10), the trap makes an attack as an opportunity action. After that, roll initiative and the trap attacks on its turn as a standard action.
Attack * LightningStandard Action or Opportunity Action      Ranged 3
Target: One, two, or three creatures within the 15-square area of effect.Attack: +14 vs. ReflexHit: 2d8 + 8 lightning damage, the target is knocked prone, and the target is slowed until the end of its next turn.Special: The trap does not target the ivy heart or the undead.Countermeasures     Once the door is properly opened by touching the key to the tapestry in location 12, the trap is deactivated.
     Aside from deactivating the trap as described above, the characters cannot affect the trap; the magic empowering it is too strong. The characters can, however, move out of the trap’s area of effect. If 3 rounds pass without a creature entering the area, the trap resets.

Published in Tomb of Horrors, page(s) 38.