100-foot long, 5-foot wide lightning strikes from you in a direction you choose. Each creature in the line must make a Dexterity save. The spell deals 4d6 lightning damage on a failed save, or half as much on a successful one. Flammable objects that aren't being worn or carried are ignited.
At Higher Levels: The damage increases by 1d6 for each slot level above 3rd.