Upon playing Treasure Hunter for the first time, players are given the mask for free and this message: You've received a Troll Slayer Mask! You can win additional slayer masks for different creatures on Treasure Hunter!
It provides several bonuses for players looking to train their Slayer skill, including bonus experience, extra damage, and double drops. Players must wear the mask in order to get the kills counted.
After killing 100 Trolls, the mask will become a Helm of the Troll. The helm has similar benefits, but does not provide bonus experience, extra damage, or double drops.
Once every day (day resets at midnight UTC), while wearing the relevant mask, the next assignment the player receives will be trolls. They will still need to go to a Slayer Master that normally assigns these creatures (Turael, Chaeldar or Sumona) – if they do not, the player will be told which Slayer Master assigns them. This does not work if they are in the process of setting up a co-op Slayer assignment.
The mask confers the same damage boost against trolls (but only while on assignment) as the slayer helm.
Killing trolls while wearing this mask will grant additional Slayer experience.
Killing trolls while wearing the mask will grant additional drops for every 10th kill. This does not double effigy or clue scroll drops, but it does double charm drops.
Every creature killed is tallied while the mask is worn. Each mask has a set amount of kills assigned to it that, once reached, "uses up" the Slayer experience and double drops effects, and turns the mask into a helm. The kill count continues to be tracked beyond this point, up to 1,048,575 on the item's tooltip. However, only up to 999,999 can be displayed to others with the "check kills" option.
A right-click option announces total kills of that creature. The announcement of total kills is not seen in the chat bar but is seen above your character by those around you. If the helm has yet to be unlocked, there’s also a message to say how many more kills are needed to do so.
After the helm version has been unlocked, the player is free to switch between it and the mask version, as a cosmetic preference only – this does not restore the Slayer experience and double drop effects to the mask.