New to Sly Flourish? Start Here or subscribe to the newsletter.

The Kickstarter for my latest book, The City of Arches, begins August 6th! Sign up to be notified on the launch of this high-fantasy city sourcebook for Lazy GMs!

Lazy Trap Generator

by Mike on 27 January 2014

Being creative is hard. The creative load is hard enough that, many times, our minds will trick us into spending time on anything anywhere to avoid having to really buckle down and create shit. The life of the typical GM includes a lot of creating things.

Taking the Cognitive Load off of the GM

The best tools to help us GMs are the ones that can help us remove some of the creative load. A good random name generator, for example, can take a lot of stress off of us when we need to name some random NPC during our games. Preprinted poster maps can help you set up an interesting location for a scene without a whole lot of stress. Random tables of all sorts can help you fill in a scene when your imagination seems to stall.

Today we're going to add one additional tool to your creative arsenal, a tool that goes hand-in-hand with the idea of lazy traps, the random trap generator.

Killing Your PCs In Four Easy Steps

The random trap generator isn't a simple static list of traps. It's a matrix of lists that, when mixed together, create powerful, deadly, and unique traps.


Roll 1d20 to determine the trigger for the trap.

  1. Idol on pedestal
  2. Weapon on altar
  3. Alternating floor tiles
  4. Proximity to statue
  5. Treasure chest
  6. Shelf of books
  7. Book on pedestal
  8. Statue holding a real sword
  9. Tiny threads strung across the room
  10. Door
  11. Glass orb that vibrates with sound
  12. Wall art
  13. Common spoken word
  14. Magnets
  15. Child's toy
  16. Loose satchel
  17. Throne
  18. Manned peepholes
  19. Hanging rope
  20. Giant knockers

Trap Type

Roll 1d20 once for a simple trap or twice for a more complicated trap.

  1. Crossbows
  2. Darts
  3. Pit
  4. Delicate pots
  5. Moving walls
  6. Boiling oil
  7. Spears
  8. Gas expulsion
  9. Floor spikes
  10. Catapult
  11. Bear traps
  12. Flying razors
  13. Swinging axe
  14. Electrical rods
  15. Falling rocks
  16. Ballista
  17. Released construct
  18. Magical gem
  19. Magical glyph
  20. Otherworldly spirit

Element Type

Roll 1d20 once or twice to determine an elemental effect for the trap. If it makes sense, you can add this elemental effect to the trap such as flaming crossbow bolts or a bottomless pit that sucks like a vacuum.

  1. Fire
  2. Lightning
  3. Sonic
  4. Necrotic
  5. Radiant
  6. Water
  7. Acid
  8. Poison
  9. Disease
  10. Cold
  11. Cursed
  12. Ooze
  13. Molten metal
  14. Dense smoke
  15. Corrosive salt
  16. Acidic rusting agent
  17. Vacuum
  18. Luminescent paste
  19. Unholy essence
  20. Dreamstuff

Resetting Mechanics

For some realism, roll 1d6 to add one of these resetting mechanics. These bits of engineering give your players the impression that these traps actually work and make sense in an environment. Somehow these traps don't just fire off once and never work again, they need to reset for the next hapless party.

  1. Hot air from a deep chasm
  2. Trapped steam pressure
  3. Large waterwheels behind the walls
  4. A complicated series of counterweights
  5. An ancient wind turbine in a hollow rock high above
  6. Enslaved outsiders reset them periodically


With this generator, we can create endless unique traps for our PCs to stumble into. Here are three examples:

A statue of a robed figure, arms outstretched, stands in this room on a floor covered with tiny holes. When the PCs come within ten feet of the statue, the arms begin to close inwards, as do the walls of the room. As the PCs attempt to move around the room, fiery jets erupt from the holes in the floor. Steam from below periodically resets the trap.

A pedestal in the center of this room holds an idol to a long forgotten god made of gold and encrusted with jewels. If any PC touches the idol, a magical glyph on the floor erupts in radiant energy, causing radiant damage and hurling the PC into the ceiling with great force.

Alternating black and white tiles cover this floor. If any PC touches a black tile, darts begin firing from the walls while spears erupt from the floor and ceiling. Every time the trap triggers, the tile triggers shift to the other color. Natives of the area regularly reset the traps.

A stairwell sits cris-crossed with tiny black threads. If any thread is tripped or cut, the person doing the tripping or cutting is peppered with crossbow quarrels and catapulted into the adjacent wall against a set of embedded spear tips. A series of counterweights behind the walls resets the trap.

It's easy to replace the trigger with any room detail you might already have. You can also simplify your trap by only rolling once on the traps list.

With this trap list in hand, you can take off some of the creative load and still provide an interesting trap for your players to face.

Related Articles

Subscribe to the Newsletter

Subscribe to the weekly Sly Flourish newsletter and receive a free adventure generator PDF!

More from Sly Flourish

Sly Flourish's Books

Share this article by copying this link:

Have a question or want to contact me? Check out Sly Flourish's Frequently Asked Questions.

This work is released under a Creative Commons Attribution-NonCommercial 4.0 International license. It allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, for noncommercial purposes only by including the following statement in the new work:

This work includes material taken from by Michael E. Shea available under a Creative Commons Attribution-NonCommercial 4.0 International license.

This site uses affiliate links to Amazon and DriveThruRPG. Thanks for your support!