Player's Handbook
1-level Conjuration
The next time you hit with a ranged weapon attack, in addition to the normal effects of the attack, the target and each creature within 5 feet of it must make a Dexterity save. A creature takes 1d10 piercing damage on a failed save, or half as much on a success.
At higher levels: The damage increases by 1d10 for each slot level above 1st, to a maximum of 6d10.