Arcane Ray

Two strokes of arcane energy in a 100 feet long and 5 feet wide ray blasts out from you in two different directions you choose. Each creature in the line must make a Dexterity saving throw. A creature takes 10d8 force damage and is knocked prone by the energy on a failed save. A creature takes half as much damage and is not knocked prone on a successful one. Creatures cannot receive damage from both rays.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for each slot level above 6th.