A curse diminishes or eliminates a character's overall effectiveness in fighting, saving against damage, or healing. Curses differ from diseases in that curses have a magical element. Curses can temporarily offset the benefits of buffs.
Many curses will reduce the chance to hit an enemy and reduce their chances to save. A few special curses exist. One, Cursed Wound, is often cast by clay golems. This curse makes you immune to positive energy effects--specifically, healing, preventing you from benefiting from any healing spells of an ally, or use healing potions. The other, Mummy Rot, combines curse with disease, which will eventually kill the character unless the curse and disease are removed, and in the right order.
Curses can also be spewed by Monks.
A Path of Harmonious Balance Monk can use the Fists of Light to apply a healing curse, which acts similar to Lesser Vampirism, restoring 1-3 HP to any party member that strikes the afflicted enemy for about 10 seconds.
Weaponry with Cursespewing or Improved Cursespewing will affect saves and to-hit attacks of enemies afflicted by it.