When worn, it completely blocks one instance of damage every 5 seconds and has 16 uses. If the wearer takes damage when the shield is not active the wearer will take full damage. Nightmare Fuel can be used to repair 4 uses or 25% of its durability. It will not disappear when its durability reaches 0%. Instead, it stays in the body equipment slot but has no effect until it is refueled.
This item is highly recommended for situations where the period between hits taken is above 5 seconds, like a kiting situation.
Additional head armor, e.g. a Football Helmet should be worn to provide protection while the Bone Armor is not active. Any other armor the player has equipped will not lose its durability whenever the Bone Armor absorbs the damage taken.
The player could also use two Bone Armors and switch between them everytime one of them is on cooldown.