Some objects, often objects of great power, have been cursed. There are many curses in the game, and they can appear on any wearable object. Curses may have a negative (or sometimes positive) effect on an object’s properties, or cause bad things to happen to the player at random.
You can choose to wear the object in spite of its curses, or attempt to uncurse it using magic. A warning: failed uncursing leads to the object becoming fragile, and a fragile object may be destroyed on future curse removal attempts. It is up to you to balance the risks and rewards in your use of cursed items.