Traps are represented by a flat object (such as a piece of fabric, plastic trash bag, etc.) cut into the shape of a polygon. A player who comes within one fall radius of the trap triggers the trap. Traps when triggered have an AOE of one fall radius unless otherwise labeled.
Only rogues or characters under the effects of a find traps spell can see a trap, until it is pointed out by another character who can see it. Other players must roleplay not noticing the trap until it is pointed out to them. (A character who has had a trap pointed out to them is able to see it and can point it out to other characters.)
The size of the object representing the trap is used to make it easier or more difficult to detect the trap, though a trap may not be smaller than 4 inches in any dimension. (A good way to check is that the trap must be able to be placed over a 4-inch circle such that no part of the circle is visible.) If the player doesn't see the trap, then the character doesn't notice it either, regardless of any ability or spell that the character may have. Note that a trap may be on the ground/floor, on a wall, door, table, or any other object or surface.
Any character who can see a trap (see above) may attempt to disarm it.
The number of corners that the polygon representing the trap has represents the ease or difficulty of disarming it. On the underside of the object, each corner is numbered. The numbers can range from 0 (zero) to ∞ (infinity).
To attempt to disarm the trap, choose one corner.
Characters who are not rogues and are not using a disarm trap spell will succeed in disarming the trap only if the corner they choose is labeled 0 (zero). (Thus they have only a 1/n chance of disarming the trap.) Rogues' disarm traps ability is equal to their rogue level. The disarm trap spell gives the caster a disarm traps ability of 3.
A trap may have one corner labeled ∞ (infinity), which means there is a 1/n chance that the trap will be triggered during the disarm attempt regardless of who is disarming it.