Adamantine Flail

This weapon or piece of ammunition is made of adamantine, one of the hardest substances in existence. Whenever this weapon or piece of ammunition hits an object, the hit is a Critical Hit.

Sap (Mastery): If you hit a creature with this weapon, that creature has Disadvantage on its next attack roll before the start of your next turn.

Proficiency: simple, flail Source: Dungeon Master's Guide (2024) p. 227