Level 3 Evocation (Sorcerer, Wizard)

Casting Time: Action
Range: Self
Components: V, S, M (a bit of fur and a crystal rod)
Duration: Instantaneous

A stroke of lightning forming a 100-foot-long, 5-foot-wide Line blasts out from you in a direction you choose. Each creature in the Line makes a Dexterity saving throw, taking 8d6 Lightning damage on a failed save or half as much damage on a successful one.

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 3.