A trap (often) needs:
Trigger(s). A form of stimulus that sets the trap off.
Component(s). Mechanical, natural, chemical, or electrical elements.
Effect(s). The way it impacts victims.
Telegraph(s). A flag to players that they should be careful.
Exclusion(s). How the trap is bypassed by those in the know. This isn’t always needed, especially for natural hazards.
I’ve made a table (or tables) for each of these, giving options for different genres based on components. Stick around for an example.
Triggers (d10)
Pressure or contact. Pressure plate, tripwire, button, lever.
Light. Presence of light, darkness, breaking light beams.
Sound. Wires that vibrate from noise.
Motion. Motion detector, moving an object, disturbing a liquid.
Specific presence. Sigil sensitive to the presence of iron.
Key. Rigged chest or door, could be triggered by the key or by not using it.
Temperature. Activates when ice melts.
Current. Changes to a flow of water or electrical current.
Time. Trap is periodically active on a timer.
Sight. The trap can ‘see’, or the trap is triggered by being seen.
Mechanical components (d12)
Cable, rope, wire, or belt.
Winch or pulley.
Spring.
Canister.
Balance.
Wheel.
Gears.
Piston.
Hinge.
Lock or catch.
Valves, vents, or pipes.
Shaft.
Natural components (d8)
Unstable structure. Crumbling ridge.
Plants. Thorns.
Vents. Volcanic systems.
Weather or climate. Storm.
Geology. Sheer cliffs, sharp rocks, sinkholes.
Water. Fast river, slick rocks, ice lakes.
Viscosity. Bogs, quicksand.
Animals. Poisonous snakes.
Chemical components
Chemical reaction trigger (d6):
Exposure to air.
Mixing of compounds.
Exposure to light.
Application of pressure.
Change of temperature.
Electrical current.
Effect of reaction (d8):
Gas or foam production.
Produces electrical current.
Phase change (e.g. liquid to solid or thickening).
Colour change.
Sound or vibration.
Oxidation (e.g. fire or explosion).
New compound produced.
Emits or absorbs heat.
Electrical components (d12)
Wires or cables.
Circuit board.
Bulb or LED.
Monitor or display.
Battery or generator.
Capacitor.
Computer chip.
Data storage.
Transmitter (radio, wi-fi).
Magnet.
Sensor (heat, light, magnetic field, acceleration).
Microphone or speaker.
Effects (d10)
Damages health. Swinging blades.
Prevents or impedes movement. Falling cage.
Navigational shift. Slide into a different room.
Affects an opportunity. Slab dropped to destroy bridge.
Separates the party. Dropped portcullis.
Destroys or damages equipment. Armour-melting acid.
Psychological effects. Possession rune.
Inflicts long term issue or debuff. Disease.
Alert system. Chimes.
Confusing or misleading. Reverse gravity.
Telegraph (d10)
Previous victims.
Visual environmental damage.
Visible mechanism.
Noises.
Smell.
Unusual pattern.
Temperature change.
Unusual texture.
Vibrations.
An enemy stands ready by a trigger.
Exclusion (d6)
Biology. Isn’t active or dangerous for certain species.
Keys or passes. Bypassed by using a physical key.
Memory. A memorised path or pattern avoids the trigger.
Manual trigger. Has to be triggered by an NPC.
Time. Only active at certain times.
Code. A keycode, input sequence, or password.
Example
Trigger: Temperature. Mechanical component: Wheel. Effect: Destroys an opportunity. Telegraph: Visible mechanism. Exclusion: Biology.
Here’s where my mind went.
The room has a vent that blasts pressurised steam into a paddle wheel that holds a steel gate open via a chain. This is designed so that if the furnaces in the dungeon are inactive, the gate is shut. The steam fills the room and is burning hot. Blocking the vent will cause the gate to close.
All the mechanisms are visible from doors into the room. The denizens who use this part of the dungeon are resistant to high temperatures.
That’s a nice puzzle trap for folks to solve right there! I’ve enriched it with some things, like the steam being another hazard to contend with, but this is a trap I would use.
Go cook up some yourself! By my count, there’s 366,000 unique combinations here and that’s with only one component.
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This is great!
I've always been inspired by Tasha's Cauldron of Everything, with combination traps.
You could easily string three of these together for something truly devilish😈
This is awesome! Using it in my dungeon creation, however, I have noticed one thing which feels like it is missing - a "magical components" option. Something I might throw together and throw in this chat once I get round to it!