The Inquisitor's mace is a one-handed crush weapon requiring 80 Attack to wield. Received as a drop from The Nightmare, it has bonuses nearly identical to the Ghrazi rapier and blade of Saeldor, acting as the crush variant of these weapons; unlike those weapons, it also has +2 Prayer bonus.

Once belonging to Phosani, a former Saradominist Justiciar and one of the founders of Slepe, the Inquisitor's mace had remained sealed in the Sisterhood Sanctuary deep beneath Slepe until The Nightmare's arrival unearthed it.

The Inquisitor's mace, along with the pieces of Inquisitor's armour, counts as a Zamorakian item in God Wars Dungeon, providing God-related Protection. The mace can be used to train all the combat stats (Attack, Strength, Defence) while on crush whereas most other melee weapons have singular strengths. Furthermore, each piece of Inquisitor's armour provides a +2.5% accuracy and damage bonus instead of the usual +0.5%. However, there is no extra bonus for wearing the full set, resulting in a total bonus of +7.5% rather than the standard +2.5%.