Enchanted onyx bolts are enchanted with the Life leech enchantment. This gives the bolts a chance of doing 20% extra damage and healing the attacker's Hitpoints by 25% of the total damage dealt. This does not work on the undead, as they have no "life" to leech. The special effect has a 10% chance of activating in PvP and a 11% of activating in PvM. If the player has completed the Hard Kandarin Diary then these values increase to 11% and 12.1% respectively. The Kandarin Diary boost is always active regardless of whether the headgear is equipped.