Enchanted ruby bolts are adamant bolts tipped with ruby bolt tips and enchanted with the spell Enchant Crossbow Bolt (Ruby) by a player with level 49 Magic. The spell enchants 10 ruby bolts at a time and uses 1 blood rune, 1 cosmic rune, and 5 fire runes.
Enchanted ruby bolts have a chance of activating the Blood Forfeit effect. When activated, damage dealt to the target will be 20% of the opponent's current Hitpoints with a cap of 100 damage  and at the cost of 10% of the player's current Hitpoints. The effect does not activate if the player cannot spare the hitpoints below 10. A long, shrieking noise can be heard when this activates.
For low hitpoint opponents, this effect can be disadvantageous because the effect overrides bolts damage (Example bolt activates against 99 hp opponent. Damage dealt will be only 19 when without activating you could be hitting 50).
This enchantment is especially effective against opponents with a high number of Hitpoints, such as black dragons. These bolts are most often used in boss-hunting, commonly against God Wars Dungeon bosses such as Kree'arra and Commander Zilyana.
The special effect has a 11% chance of activating in PvP and a 6% of activating in PvM. If the player has completed the Hard Kandarin Diary then these values increase to 12.1% and 6.6% respectively. The Kandarin Diary boost is always active regardless of whether the headgear is equipped.