Arcane Riposte A5E

1st-level evocation

Casting time: 1 reaction, which you take when a creature makes a melee attack against you
Range: Self
Components: V, S
Duration: instantaneous
Attack: Spell attack roll
Damage: 3d6 Acid, Cold, Fire, Lightning, Poison, Thunder

You respond to an incoming attack with a magically-infused attack of your own. Make a melee spell attack against the creature that attacked you. If you hit, the creature takes 3d6 acid, cold, fire, lightning, poison, or thunder damage.

At higher levels

The spell deals an extra 1d6 damage for each slot level above 1st. When using a 4th-level spell slot, you may choose to deal psychic, radiant, or necrotic damage. When using a 6th-level spell slot, you may choose to deal force damage.

Source: Adventurer's Guide (EN Publishing) · License: Creative Commons Attribution 4.0 / OPEN GAME LICENSE Version 1.0a details