You point at a location within 100m, and a glowing, 30cm diameter ball of emerald acid rapidly streaks there and explodes in a 10m radius sphere.

Each creature in that area must make a Dexterity saving throw, taking 6d8 Acid damage and potentially afflicted by

Sap

Critical Success (+10). The target is unaffected.
Success. The target takes half damage and receives 3 stacks of Sap for 1 minute.
Failure. The target takes full damage and receives 6 stacks of Sap for 1 minute.
Critical Failure (–10). The target takes 1.5× damage and receives 8 stacks of Sap for 1 minute.

Any nonmagickal metal armour or metal shields that they are wearing takes a permanent and cumulative –2 penalty to the AC it offers. Armour reduced to an AC of 10 or a shield that drops to a +0 bonus is destroyed.

At Higher Levels. When you cast this spell using a spell slot of 8th level or higher, the initial damage increases by 1d8 for each slot level above 7th.