Usually this is for tools, weapons and armor but can easily extend beyond them.

"Depletable" items should not be considered, such as is the case of most armor in older games.

This is efficient way of lowering the value of items with time and use, even making them unusable after a time, and protects the item economy in multplayer games.

Many players however find item degradation to be an immense annoyance, especially if it happens unusually fast.