Certain monsters, magic items and spells have the power to drain "life energy levels", perform a "level drain", or an "energy drain" (these phrases are used interchangeably in the OSRIC rules). If a player character is drained of a life energy level, he or she loses one complete level of experience and is placed at the beginning point of the new level. If the character is multi-classed or dual-classed, then the highest level of experience attained by that character is lost. If the character has two equal levels, then the level lost should be determined randomly. A player character drained below level 1 is slain (and may rise as some kind of undead creature). Non-player characters lose a level or hit die, as applicable.