Black mask

A Black mask requires 10 Defence, 20 Strength, and 40 Combat to wear. It gives a player 15% Attack and Strength boosts against all Slayer task monsters. This effect does not stack with the damage/strength boost of a special attack, like that of a dragon dagger. The mask also has ten charges that are invoked at random against any combat opponents, not just slayer task monsters. A charge lowers the opponent's Defence level by 3-10. Once the charges are gone, there is no way to recharge it (the slab outside the cave has no effect on it), although its attack and strength bonuses remain after being uncharged.

For players on undead Slayer assignments, the boosts of a Salve amulet (unenchanted) or Salve amulet (e) do not stack with the effects of a black mask. Only one (the bigger boost) will be effective.

The effects of any prayer bonus will, however, will stack upon the already 15% attack increase on Slayer Monster bonus.

The black mask's stats are comparable to a mithril med helm.

Black masks are dropped by Cave horrors (Level 58 Slayer required), found in the Mos Le'Harmless Caves.

A 2008 update with the release of the Smoking Kills quest allowed players to craft a black mask and other slayer items into a Slayer helmet, provided they had acquired the ability to make the helmets. Slayer helmets are valued because of their effects and the fact that they are not tradable. This update, together with a rumour of lowered drop rates by monsters, was responsible for a steady price increase of the black mask, from approximately 400-500k coins to well over 900k, due to increased demand for the mask to make Slayer helmets. Two weeks after the update, however, prices for the mask began dropping in the Grand Exchange, and soon thereafter mask prices were back to the 400-500k range. More recently, it has not risen to over 700k.