Triggering Traps

So, what’s the deal with traps triggering on a 2 in 6?

Are traps just inherently unreliable, such that stepping on the pressure-plate just doesn’t always work? The trap triggers when you open the door… except most of the time it doesn’t?

Or should it be reserved for “I can’t tell exactly what you’re doing, so maybe you trigger the trap”? Like a bunch of people walk over a tripwire, but it’s possible that they’ll just accidentally step over it?

It’s not clear from the text. Is it a 4 in 6 chance of trap failure, or 2 in 6 chance of “stepping in the wrong place”?

Imagine the rogue examining a doorway. There is a trap in the doorway, triggered by stepping on a plate. Out rogue does not find the trap. So, standard is this: warrior goes first he has highest hp and best con. if there is a trap, he can take the damage. the wizard will stay back, and suffer no harm even if the trap is an area effect. boooring. now with the 2in6-rule you have. warrior steps through the door way. nothing happens. ha it’s save. rogue follows. still nothing. last, wizard. booom…perhaps the pressure plate is not balanced well and the warrior stepped onto the right place to not trigger it. perhaps the rogue’s weight was not as well distributed to trigger the trap. or perhaps the wizard was just unlucke with the rogue pressing down the plate only a little bit and then the wizard given it the rest…this is more existing. at list imho.

so yes. each time a trap can be potentially triggered you roll d6. if you roll a 1 or 2, the trap is triggered.

Another example: have you ever seen a wizard (or for that any character at the rear of the marching order) fall into a pit when not using these rules? me not, unless the pit is 20x20 ft. square, or so…

That’s true, but arguably part of the reason that the mage is in the back in the first place. :slight_smile:

Ludanto, I generally use the random chances as representative of "the average situation in which the adventurers act typically but not exceptionally." This applies to searching for secret doors, stumbling into traps, etc.

Some examples:

#1) If the party is marching at exploration movement down a dungeon corridor, in a standard marching order, the chances of triggering the pit are 2 in 6 per person. (The trap mechanism is old, it's specifically designed for a certain weight). But if the party had yoked a 800lb ox marching in front of them, the Judge could rule the ox automatically triggered a normal pit. Or, imagine there's no ox, but the pit was designed with a "hair trigger" and takes up the entire width of the corridor, the Judge could rule that the trap is triggered on a 5 in 6 per person.

#2) If the party is marching at exploration movement down a dungeon corridor, in a standard marching order, the chances of triggering a tripwire are 2 in 6 per person. But if the party were all using levitate spells to palm their way across the ceiling, the Judge could rule that the trip is triggered on only a 1 in 6 (maybe rope dangles out of a pack or something). On the other hand, if the party were sprinting down the hall, the Judge could rule the trap is triggered on a 4 in 6 per person (or whatever).

Hope that makes sense.


Thanks, everyone.

That’s about what I thought. Sometimes it just reads weird.

Ok here is a question I’ve never been able to parse. How do 10 foot poles work in this context? Do they give a 2 in 6 chance of setting off a pit before the party arrives? Also if they move normal speed through a dungeon, say running back to the surface, how would you change the exploration mechanic?

Usually, there is not enough force behing stabbing a pole onto a trigger plate at least during movement. If someone is standing still and would be able to excert full force, i would allow it or if the plate is very senvitive, i would allow it, too. For other traps, such as trip wires, the pole would be helpful. Anyway, judge’s call. In generall a pole could trigger some traps with the same (or adjusted) chance.

Running: no map making, no hearing, lowered ac, automatically surprised, no checks for traps or other secrets, etc. and eyeballing the time needed to escape by estimating movement per round (running) and then extrapolating.

I treat the 10' pole as an additional character in front of the party. The pole has a 1-2 chance of setting off a trap before the party gets to it (if both characters in front are using poles, that's 2 characters that can set off the trap). If the trap is a pit, this is very helpful. If the trap is a tripwire which causes the ceiling to collapse, this is...less helpful.


Excellent, I’ll definitely play it that way, thanks!