Force Bridge
Hazard
Level 15 Obstacle
XP 1200

A shimmering bridge of force covers a 30-foot-long and 10-foot-deep pit, which has hundreds of sharpened spikes set into its floor.

Hazard: The bridge of force allows Acererak‚Äôs servants to cross the pit, but living creatures have a more difficult passage.Perception     The characters cannot spot this hazard with Perception.Arcana     DC 18: The force field is steady and should hold any creature crossing it.     DC 23: The force field is weakened subtly by the approach of a living creature.Trigger       The hazard attacks when a living creature has moved 1d6 squares across the force field.
AttackOpportunity Action      Melee
Target: The creature that triggered the hazard.Attack: +20 vs. ReflexHit: The force field fails under the weight of a living creature. The target takes 2d8 force damage from the collapsing field, then falls prone in the pit and takes 3d10 damage.Miss: The character takes 1d8 force damage but crosses the pit.Special       If more than one character attempts to cross the pit at the same time, the hazard gains a bonus to the attack roll equal to the number of individuals attempting to cross.
    The force field re-forms immediately after a creature has fallen. A character can make a DC 20 Athletics check to climb out of the pit. A character in the pit can make a DC 25 Athletics check to break through the force field. Up to two other characters inside or outside the pit can aid this check. On a successful check, the character takes 2d8 force damage but is freed. If the check fails by 5 or more, the character falls prone on the spikes, taking 1d10 damage.
    Creatures in the pit have line of effect only to each other.
Countermeasures     With a running start, a character can make a DC 30 Athletics check to jump the force bridge. On a failed check, a character triggers the hazard, which gains a +3 bonus to the attack roll.
     A character can make a DC 25 Athletics check to climb the walls above the force bridge. On a failed check, the character triggers the hazard, which gains a +3 bonus to the attack roll.
     A creature that falls while adjacent to a square of the floor on either end of the hazard can make a saving throw to catch the edge of the pit, trapping the character part of the way through the force field. A creature that ends its turn on the edge takes 2d8 force damage, but can make a DC 25 Athletics check to climb out. Up to two other characters inside or outside the pit can aid this check.

Published in Tomb of Horrors, page(s) 73.