Arcane Volley

You summon spheres of arcane force and hurl them at a 30 foot cube within range. Each creature in the area must make a dexterity saving throw. On a failed save the creature takes 3d8 force damage and is knocked prone. On a successful save the creature takes half damage and is not knocked prone.

At higher levels. For each level above 4th the damage dice goes up by 1d8.