There is a chance when setting a bear trap or arming a land mine that you mess up and trigger it on yourself. This is done by checking to see if you would fail had you been untrapping it. If you would fail, then there is a 1/5 chance you trigger the trap on yourself.

When someone gets out of a bear trap (or is killed while in it), it removes the trap and drops a beartrap item on the ground.

When you become caught in a pit, bear trap, or other restraining trap in Gehennom, nearby demons become alerted and aware of your exact location, because they’re the ones who set the traps in the first place.

The game should support poisoned bear traps (that deal extra poison damage much like a poisoned spiked pit does), and it should be possible for the player to manually poison a beartrap item.

Many bear traps generate on the Ranger quest.

Rangers have a significantly better chance than other roles at untrapping beartraps (perhaps even just 100%).

When the player or any monster frees itself from a beartrap, it removes the trap and puts a beartrap item there instead. The trap shouldn’t magically become primed again.

Beartraps are much lighter so as to make them feasible to carry around, and Rangers start out with two or three of them.

Rangers get an alignment bonus for disarming naturally-generated bear traps, or possibly for catching a hostile monster in a player-set bear trap.

After you struggle free of a bear trap, it becomes disarmed.

Armed bear traps and land mines can be teleported away if hit with a teleportation beam.

Zapping a wand of opening down at a bear trap you are stuck in should free you immediately.

Bear traps injure your legs like xans do.