PHB
0-level (Cantrip) Necromancy
Channeling the chill of the grave, make a melee spell attack against a target within reach. On a hit, the target takes 1d10 Necrotic damage, and it can't regain Hit Points until the end of your next turn.
This spell's damage increases by 1d10 when you reach 5th level ( 2d10 ), 11th level ( 3d10 ), and 17th level ( 4d10 ).