[LadyLightning]

Better yet, make a dungeon prefix where it makes the dungeon pitch-black,
and only Vampires, Grimalkin and Felidae could see in there without the use
of a light source, because Darkvision. Liches could be their own light source,
because they're made of energy -- this could be represented by an item
called a Lich-Light that goes in their inventory and functions like a handheld
light that never burns out.

Speaking of which, make candles, lanterns and torches burn out after some
in-game hours, like 2 for candles, 3 for torches, or 5 for lanterns. Candles
could weigh 0.1, torches could weigh 1 and have a bigger radius, and then
lanterns could weigh 1, and burn oil flasks that weigh 0.1, and have the
biggest radius.