Another cantrip I was thinking about lately. I like acid that eats armor.
Casting Time: 1 action
Range: 50 feet
Components: V, S
You create a glob of acid in your hand and throw it at a target in range. Make a ranged spell attack at a target. On a hit, the target takes 1d4 acid damage, and if the target’s armor is not magical, the target’s armor takes a -1 penalty to AC. This penalty is not cumulative with itself or other magic spells. Additional spells that reduce the AC of a target apply the highest penalty to the target’s AC instead of the total penalty.
This spell’s damage increases by 1d4 when you reach 5th level (2d4), 11th level (3d4), and 17th level (4d4).