Blastbolt

An explosive blast of energy erupts from your palm. Make a melee spell attack against a creature you can touch. On a hit, the target takes 1d12 force damage. If you roll a 1 or 2, the spell goes awry, and both you and the target take damage.

This spell's damage and backfire damage both increase by 1d12 when you reach 5th level (2d12), 11th level (3d12), and 17th level (4d12).