|This magical trap can displace anyone hapless enough to step on it - or even fly above it - to a random place on the same dungeon level.|
A teleport trap is a magical trap that instantly teleports any character or monster that walks on it to another location on the level. Teleport traps are not mechanical and cannot be avoided by flying. Because they are an instantaneous form of teleportation, they make for good emergency escape routes, especially if you've already explored most of the current floor.
Teleport traps come in two varieties: temporary and permanent. Temporary teleport traps vanish after activating once, while permanent teleport traps allow for unlimited use. Permanent teleport traps are only found in particular vaults, often serving to guard specific items. If you come across a teleport trap that is blocking you from reaching an item or area you wish to explore, remember that a source of stasis will render it ineffective. Alternatively, Apportation will allow you to simply grab the items from a distance.
If an item is on a teleport trap, moving onto the trap (with autopickup on) will not gain you the item; you will always teleport before any pickup attempt can be made. If the trap was temporary, however, you may simply return to the spot and grab the now-unguarded item.
Prior to 0.16, there was still a 'disarm trap' command. Prior to 0.16, traps did care about whether the player is flying.
Prior to 0.15, all teleport traps were permanent.