Shattermace (5e Equipment)
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Weapon (mace), rare
Almost made solely out of obsidian, Shattermace is a jagged, but very well crafted piece. Thanks to it's material makeup, however, it is prone to temporarily breaking.
Attacks made with this weapon deal an extra 3d6 bludgeoning damage. However, when you make an attack roll with this weapon and roll a 1, it immediately breaks after the attack is resolved. Shattermace becomes unusable, until an hour passes, at which point it reforms at it's location of breaking.