Wizards know how it is. Sometimes you go a little far with your designs and create a trap that’s dangerous and unpredictable—but useful! (See the previous Traps a Mad Wizard Must Have Designed here!)
Sometimes trap designers want a big finish and aren’t too worried about reusability. Or maybe it’s about creating a spectacle as someone is crushed, turned to ash, or lost in the unfathomable depths.
Whatever a wizard’s bent, the four traps below are either permanently destroyed after they go off, or they’d be near-impossible to reset. In some cases, this means serious consequences for anyone caught inside when they trigger.
The traps described here are loosely based on scenes from famous TV shows and movies. Some details have been left vague to make them easier to add to your existing campaign.
Elaborately Complex Bridge
Trap [Mechanical]
To keep would-be intruders out of an underground city, builders designed a stone bridge to collapse unless it is crossed by an intricate series of steps. The bridge is 40 feet wide and 200 feet long, made of thick, 5-foot-square blocks, and it hangs over a river of lava. It is best placed at the entrance to an ancient ruin but could go somewhere more populated that doesn’t like visitors.
Trigger: When a creature steps on an incorrect block, the trap triggers. Faded text carved into the ground before the bridge is barely visible with a successful DC 12 WIS (Perception) check. It reads: Odds fall, but evens demand fair play. Tenths are lateral. Translation: step on odd-numbered blocks only, switch to even-numbered halfway across. Make a lateral move at every tenth row before continuing.
Effects: A single, 40-foot row of blocks in the center of the bridge falls into the river. Each subsequent round, a new row on both sides of the gap simultaneously collapses, increasing the size of the gap. This continues until the entire bridge has fallen away.
Resolution: PCs who fall can make a DC 12 DEX check to catch themselves. On a success, they grab an adjacent block. On a failure, they fall.PCs who fall into lava die. In addition, a switch is hidden under the left side bridge post. A PC can find it with a successful DC 20 WIS (Perception) check. Pressing it temporarily disables the mechanism. Once pressed, PCs hear a soft ticking sound counting seconds. After 60 seconds, the trap is active again. An identical switch is on the bridge’s other side.
Hands Off
Trap [Complex Magical]
An important item is hidden in a massive underground cavern packed with treasure—a wondrous cavern, if you will. The entrance is shaped like a panther skull rising from the earth. When the PCs enter the skull’s mouth, a booming voice demands to know what item they seek. It warns them to touch nothing else. Place one item of great interest or potential value to each PC on display inside the cavern as temptation.
Trigger: Touching any item other than the specific item the creatures are searching for angers the panther warden.
Effects: The booming voice returns, calling the creatures inside thieves, brigands, and worse. The cavern begins to collapse as the panther mouth grinds closed. Creatures in the cavern must make a DC 12 DEX save for every 120 feet they move. On a failure, a creature takes 3d6 bludgeoning damage from falling rocks.If the creatures do not leave the cavern in 2d4 rounds, the panther mouth slams shut and melts into the earth, killing anyone inside.
Resolution: Not touching a forbidden item allows creatures to leave the cavern without incident. Getting outside the cavern removes creatures from danger.
Just a Boulder
Trap (Mechanical)
An item of importance is hidden in a large, spherical chamber at the end of a hundred-foot tunnel. The item rests in the center of the room on a stone pedestal with a noticeable circular base. If the weight on the pedestal shifts, the pedestal sinks into the ground, a massive boulder falls from the ceiling, and it begins rolling toward the cave’s entrance.
Trigger: Removing the object without replacing its precise weight triggers the trap. A successful DC 12 INT ability check allows a creature to avoid triggering it by estimating the weight correctly and replace the item smoothly. A successful DC 10 WIS (Perception) or INT (Investigation) check allows a creature can locate the circular opening where the boulder will appear.
Effects: For 1 round, nothing happens.Then for 1 round, creatures hear a distant rumbling. On the third round, a huge, round boulder appears, filling the tunnel entirely as it rolls toward the creatures. Each round, running creatures must succeed on a DC 10 STR (Athletics) check or fall prone. Two subsequent failures results in 4d10 bludgeoning damage from the boulder crushing them before rolling away.
Resolution: Once the boulder has passed a creature in the tunnel, the trap is no longer a threat to it. Whether creatures have an item of equivalent weight to replace the object and circumvent the trap is up to GM discretion.
Ship Set to Blow
Hazard (Environmental)
An ancient, landlocked sea vessel in a remote location seems unusual. However, the crew tucked crates of explosives into corners above and belowdecks (they might be magical, or just regular old gunpowder), and they deliberately laid long fuses between them to punish would-be treasure hunters.
Trigger: If an uncontained flame is used anywhere on board, roll a d6. On a 5 or 6, a nearby fuse ignites. Other environmental effects might also trigger this, at the GM’s discretion. A lit fuse reaches an explosive in 1d4 rounds. A creature can notice unlit fuses with a successful DC 10 WIS (Perception) check. Lit fuses are plain.
Effects: A creature within 10 feet of an explosion must succeed on a DC 15 DEX save or take takes 3d6 fire damage. Then roll a d6. On a 4, 5 or 6 the explosion triggers another nearby fuse. Repeat as necessary.
Resolution: A lit fuse can be snuffed out in a variety of ways. Cutting every fuse significantly reduces the danger, assuming that a searching creature can find them with a successful DC 15 WIS (Investigation) check.
