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.
Using a Higher-Level Spell Slot. 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.