You take the rust between your hands and rub them around while saying the incantation. They become a small sphere of acid that is able to be thrown a target within range.
Make a ranged spell attack.
On a miss the orb lands on an unoccupied space near the target and immediately becomes a pool of acid, while there the area counts as difficult terrain and anyone that moves through the space takes 1d4 acid damage and their shoes or boots loose one durability point as described below. This acid remains for the duration of the spell.
On a hit the caster determines what part of the body this spell impacts: Head, Torso, Left or Right Arm OR Left or Right Leg. The orb explodes on impact covering the affected area in corrosive acid. You start concentrating on keeping the acid in existence.
Where the acid lands the equipment in contact with that part of the body, including any weapon or shield starts being burned away as the acid destroys the equipment.
Normal equipment has a durability point maximum of 3, magical items have 5, artifacts have 7. For each turn a piece of equipment is covered in the acid, it loses a durability point.
Water or almost any other basic liquid can remove the acid (alcohol of any kind and more acid does not remove). Additionally, for each turn the area of the body remains affected, you target takes 3d8 Acid damage. A target can remove the equipment to remove the damaging effect, but as long as you are concentrating on this spell the durability points will still go down. If this spell destroys one part of a pair-such as gloves or boots-if they are magical, they lose their effects. Otherwise the target just loses a piece of the pair.
Using a Higher-Level Spell Slot. The areas of the target that can be hit on the target of the ranged spell attack increase to one more for each level above 4th.
* - (bits of rust)
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