Blastbolt (5e Spell)
From D&D Wiki
|Casting time:||1 action|
An explosive blast of force 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 the d20 for your attack roll lands on a 1 or 2, the explosion backfires, and you take 1d12 force damage instead.
This spell's force damage and backfire damage both increase by 1d12 when you reach 5th level (2d12), 11th level (3d12), and 17th level (4d12).