Undead are the animated remains of the dead, driven by negative energy. Since they do not depend on the functioning of organs, they are immune to sneak attacks, critical hits, mind-affecting spells, paralysis, poison, and disease. Since they are already dead, they are immune to death magic, level drain, and ability drain. Because of their driving force, undead are healed by spells inflicting negative energy damage (but not by weapons inflicting this damage type due to game engine limitations). Several undead are vulnerable to divine damage.
Clerics, paladins and blackguards may turn undead, which causes the undead creature either to flee in fear or be destroyed altogether. All classes may use garlic to gain an advantage (+2 attack bonus) against undead creatures for a minute.
See also: Category:Undead