One wrong step in an ancient tomb triggers a series of scything blades that cleave through armor and bone. The seemingly innocuous vines that hang over a cave entrance grasp and choke at anyone foolish enough to push through them. A narrow stone bridge leads over a pit filled with hissing, sputtering acid. In the D&D game, monsters are only one of many challenges that adventurers face.
If it can hurt the party, but it isn't a monster, it's either a trap or a hazard.
Trap or Hazard?
What's the difference between a trap and a hazard? Traps are constructed with the intent to damage, harry, or impede intruders. Hazards are natural or supernatural in origin, but typically lack the malicious intent of a trap. Though both feature similar risks, a pit covered with a goblin-constructed false floor is a trap, while a deep chasm between two sections of a troglodyte cave constitutes a hazard.
Traps tend to be hidden, and their danger is apparent only when they are discovered with keen senses or a misplaced step. The danger of a hazard is usually out in the open, and its challenge determined by the senses (sometimes far too late) or deduced by those knowledgeable of the hazard's environs.
The common link between traps and hazards revolves around peril -- both to adventurers and monsters. Because of this similarity, traps and hazards feature similar rules, conventions, and presentations.
And, here are three traps for your perusal:
Whirling Blades Level 5 Obstacle
Trap XP 200
Blades rise out of hidden compartments and spin wildly across the chamber.
Trap: A whirling blades contraption emerges and spins like a top, moving its speed in a random direction and attacking each round.
Perception
DC 22: The character notices trigger plates around the chamber.
DC 27: The character notices the hidden control panel.
Initiative +7 Speed 4
Trigger
When a character moves into a trigger square, the whirling blades contraption emerges and attacks.
Attack
Standard Action Close burst 1
Targets: All creatures in burst
Attack: +10 vs. AC
Hit: 3d8+3 damage
Countermeasures
A character can engage in a skill challenge to deactivate the control panel. DC 22 Thievery. Complexity 2 (6 successes before 3 failures). Success disables the trap. Failure causes the whirling blades to act twice in the round (roll a second initiative for the trap).
A character can attack the whirling blades contraption (AC 16, other defenses 13; hp 55; resist 5 all) or the control panel (AC 14, other defenses 11; hp 35; resist 5 all). Destroying either disables the entire trap.
Flame Jet Level 8 Blaster
Trap XP 350
Two hidden nozzles let loose a blast of flame.
Trap: When the trap is triggered, two hidden nozzles in the walls attack each round on their initiative.
Perception
DC 24: The character notices the nozzles.
DC 28: The character notices the control panel on the far side of the room.
Initiative +5
Trigger
When a character enters the blast area of one of the flame jets, it makes its first attack as an immediate reaction. It then rolls initiative, attacking each round.
Attack
Immediate Reaction or Standard Action Close blast 3
Targets: All creatures in blast
Attack: +11 vs. Reflex
Hit: 3d8+4 fire damage and ongoing 5 fire damage (save ends).
Miss: Half damage, no ongoing damage.
Countermeasures
An adjacent character can disable one flame jet with a DC 24 Thievery check.
A character can engage in a skill challenge to deactivate the control panel. DC 28 Thievery. Complexity 1 (4 successes before 2 failures). Success disables the trap. Failure causes the control panel to explode (close blast 3, 3d8 + 4 damage to all creatures in blast) and the trap remains active.
Upgrade to Elite (700 XP)
Increase the Perception and Thievery checks by 2.
Increase the number of nozzles to 6, or to 3 with a larger area of close blast 5.
Soul Gem Level 26 Solo Blaster
Trap XP 45,000
A strange, many-faceted gem in the center of the chamber suddenly emits blasts of blinding light.
Trap: This fist-sized cut crystal is often embedded in a statue or placed on a pedestal in the center of a room. When a creature steps within 5 squares of the soul gem, it starts emitting blasts of radiant power from its many facets.
Perception
DC 29: The character spots the strange gem.
Additional Skill: Arcana
DC 33: The character recognizes the soul gem.
Initiative +8
Trigger
When a creature moves within 5 squares of the soul gem, it rolls initiative and attacks.
Attack
Standard Action Close blast 5
Targets: All creatures in blast
Attack: +29 vs. Fortitude
Hit: 4d10 + 5 radiant damage and ongoing 5 radiant damage and stunned (save ends).
Aftereffect of stun: Dazed (save ends).
Special: Each round, roll 1d8 to determine the direction of the blast. The blast is centered on one square of the gem's space, starting with the north square and moving clockwise around the gem's space.
Countermeasures
A character can engage in a skill challenge to detach the soul gem from its socket and thereby disable it. DC 37 Thievery. Complexity 1 (4 successes before 2 failures). Success detaches the gem and disables the trap. Failure causes the gem to explode (close burst 8, 4d10 + 5 radiant damage and stunned (save ends) to all creatures in burst).
A character can attack the gem (AC 33, other defenses 29; hp 100; resist 15 all). When reduced to 0 hit points, the gem explodes in a close burst 8, as above. Destroying the gem disables the trap.
