Embrittlement

You spray a creature in range with a small, but powerful amount of acid. Make a ranged spell attack, on a hit, the target takes 2d4 acid damage. Until the start of your next turn, the target has vulnerability to bludgeoning damage. This effect ends early if the creature immerses itself in water, sand or earth.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d4 for each slot level above 1st.