Spell of dimension door, a level 2 or 3 escape spell that is intended as a weaker version of teleport away: it randomly teleports you, possibly suppressing your teleport control, and if you do successfully teleport, two bidirectional teleport traps are created on your starting and ending position. The traps last only a few turns before disappearing, but monsters will be able to follow you through it until then.

Make the Gnomish Sewers Mines’ End in EvilHack less aggravating for the player who lacks teleport control: instead of having to jump into teleport traps and teleport around the level randomly until winding up in the hidden luckstone room, make one specific teleport trap always direct to that room.

Polymorph, teleport and levelport traps should disappear once used by any monster (including the player). Or else they have a low-ish chance of disappearing per each use.