A black light is always generated invisible, but illuminates its surroundings in a 3x3 area centered on itself. Black lights attack by exploding (destroying themselves in the process), causing 10d12 turns of hallucination if the target is the hero, and confusion if the target is a monster . Unlike a gas spore explosion, the explosion of a light only affects the square targeted.
Black lights may attack pets if angered by them, or if the hero is displaced and the pet is at the hero's perceived location, so it may be advisable to keep strong pets away from black lights, if possible. Monsters don't have a confusion timer; instead, they have a 2% chance of recovering on each of their moves.
The explosion of a black light will wake nearby sleeping monsters.
The best course of action is to put on a blindfold or towel and wait for it to explode, or to have a potion of full healing or a unicorn horn handy. In a large unlit area, such as is common in the Gnomish Mines, the presence of a black light can be detected as a moving but invisible source of illumination. Grayswandir negates the effects of hallucination, but only as long as it is wielded.
Strange creatures formed from energy rather than matter,
lights are given to self-destructive behavior when battling