Dec 30, 2020

Trapplications II

Five years ago, I wrote the original Trapplications post. After years of updating it based on use, it's time to present the more streamlined version I've adopted. This version is better for stocking and restocking dungeons, while also remaining usable in play as a "wandering trap" table.

To recap: To use this table, you roll 2d6 and 1d6 at the same time and the results determine which entry on the grid occurs. If using it during play, I roll about once per 10-minute exploration turn because it's easier to remember to do it that way. If I'm using it for stocking, I roll it once per room, and then once more per room every time I restock the dungeon, and occasionally for corridors with prominent room-like features.

The big update is the categories for the 1d6. I redesigned them because these ones are easier to understand and less work to create than the old set, with a clear progression in proximity, danger, and imminence between the three options on the table, and the need to only create 3 columns of content instead of a full six.

They are now:

1 - Null
2 - Null
3 - Null
4 - Signs
5 - Danger Zone
6 - Trigger

"Null" results mean nothing - no trap, no problem. These results help with stocking by ensuring that some rooms lack traps. 

"Signs" means indirect signs of the trap's operation - corpses strewn around, poison darts littering the floor, the sound of grinding gears or whirring blades far ahead. The intent is that they can be spotted ahead of the trap being an actual danger.

"Danger Zone" means one or more PCs find themselves in the area of effect of a trap that has not yet activated. When stocking, it means that trap has an area of effect that one can enter into without automatically triggering the trap. If the PCs freeze in this state they'll be fine, but the challenge is to extricate themselves without triggering the trap (perhaps by dismantling or jamming it?).

"Trigger" means that a trap triggers or is about to trigger with a PC in its area of effect. When stocking, it means a trap that can't be noticed through passive observation until it's triggered (a careful search of the area might reveal it ahead of time). 

I tend to make the entries here the actual triggers of the traps, even tho' this will require a bit of adaptation if you're using it in play when the specific object isn't necessarily present. Reusing triggers for traps helps PCs learn what kinds of things in this dungeon are likely to be dangerous and gives them an extra chance to avoid them, while also bringing a certain conceptual coherence to the traps.

The probability here is that 50% of rooms will have traps, and only 1 in 3 traps will immediately trigger without warning, which I think is frequent enough to be dangerous but not frequent enough to slam a halt on exploration. I recommend attaching "Trigger" results to interactable objects whenever possible

If you feel that's too many, I'd use a d8, push "Trigger" to 8, "Danger Zone" to 7, "Signs" to 6, add a "Broken" column at 5, and leave the rest as nulls. That reduces the number of traps that are difficult to discover beforehand to 12.5%.

implies a trap that's been activated and not reset, or that has broken down from age. Broken traps are a great way to telegraph that there are traps around, and create a sense of danger without actually requiring time to resolve in any detail.

Here's an example of this larger table:

Happy new year!


  1. Would love to see that as part of a bigger system for restocking / dynamic encounters / dungeon generation! I'm a sucker for these kinds of things.

    Also, I suggest adding another line and using 1d12 rather than 2d6 to avoid towards pit traps, for example (unless that's intended)

  2. Thanks for this, I too love this sort of thing and would love to see a full series of articles on restocking systems.

    I originally was going to say "This article reminds me of the Monster/Lair/Spoor/Tracks/Traces procedure for wandering monsters" and then realised it was you who wrote that article I believe!

    @ Tûk / Kek I think the decision to use 2d6 is intentional, after all Laser Eye Statues and Mini Black Holes definitely *sound* like rarer traps than Pit Traps, Crushing Blocks and Poison Darts.