The beads of this silver abacus seem to um faintly, and glow when they're moved.

This abacus has 3 charges. While holding the abacus, when a creature you can see within 60 ft. of you makes an attack roll, ability check, or damage roll, you can use your reaction to expend 1 charge, roll a d6, and either add or subtract its total to the aforementioned roll.

This abacus regains any expended charges daily at dawn.

Notes: Buff, Debuff, Utility, Combat