Magic item creation can have unexpected results when the creator tries to craft something beyond his or her abilities. Most cursed items were created by accident, though some wicked makers create them intentionally, to laugh as their wielders march toward doom.
A cursed item usually appears benign. The wielder knows all of the item’s powers, but the properties remain hidden until triggered. Once a character triggers the property, the character cannot get rid of the item by any means short of a Disenchant Magic Item ritual, a Remove Affliction ritual, or similar magic.
Published in The Book of Vile Darkness, page(s) 2-74.