The bonecrusher is a reward from the hard task set of the Morytania Diary. Players can obtain a Bonecrusher from the Ghost disciple in the Ectofuntus building. When carried in the inventory, it will automatically crush bones upon killing a monster. However, players only receive half the Prayer experience with the completion of the Hard tasks. In order to obtain full experience per bones, players must complete the Morytania elite tasks.
, A common use for the bonecrusher is when using prayer in the Catacombs of Kourend, as burying bones inside the catacombs restores a number of prayer points. Bones automatically crushed by the bonecrusher while inside the Catacombs of Kourend also have this regenerative effect, wherein normal bones restore one prayer point, big bones restore two prayer points, and dragon bones restore four prayer points. Dragonbone necklace has the same effect, although it does not stack with the Catacombs of Kourend prayer restoration.

The bonecrusher can be recharged using ecto-tokens, giving 25 charges per token. The charge limit is 2,147,483,647. Should the player die with the bonecrusher anywhere except above level 20 Wilderness, it will always be protected on death and will retain all of its charges. The bonecrusher uses one charge for every bone crushed automatically upon kill.

The bonecrusher also does not auto-crush bones obtained as a secondary drop. This includes drops such as long and curved bones, as well as extra bone drops from monsters such as bloodvelds. Bones dropped as notes are not affected by the bonecrusher.

A good method to obtain constant charges is to perform the Ectofuntus daily by offering 26 or 39 bones having the hard or elite Morytania diary completed respectively, after exchanging them into bonemeal and bucket of slime from Robin.

The item needs only to be present in the player’s inventory for it to take effect, and may be found useful if players have a tendency to leave bones on the ground and not bury them. Should players not want this to occur, they can right click Activity to activate or deactivate its effect.

When a monster is killed with a bonecrusher in the player’s inventory, Prayer experience is rewarded in a way similar to Slayer experience (with bones missing from the drops), with no animation or anything similar occurring. This means that this item won’t slow players down at all compared to leaving bones on the ground. The bonecrusher has no effect on drops when it is left in the bank.

Catching Hunter creatures, which drop bones, such as those located in the Falconry will crush the bones while having the bonecrusher in your inventory.