Sap

Your Sneak Attack with a bludgeoning weapon can also stun a creature.

Prerequisite: Rogue.

Benefit: You treat all simple bludgeoning weapons (blackjack or club, light hammer, mace, quarterstaff) as finesse weapons.

Additionally, on your turn, after a successful sneak attack with a bludgeoning weapon against a creature, you can forgo 1d6 sneak attack damage and choose to sap it. The creature is allowed a Constitution saving throw to negate the effect. The DC is equal to 8 + your proficiency bonus + your Dexterity modifier. If the creature fails its saving throw, it is stunned until the end of your next turn.

Once you use this feature, you cannot use it again until you finish a short or long rest.