Erratic Fireball

You fire a volatile sphere of roiling flame, which travels an uncertain distance before exploding. You choose a direction, launching a fireball that explodes in a 20 foot radius centered on a point 2d8x5 feet away from you. Each creature in the area must succeed on a Dexterity saving throw or take 6d6 fire damage and be knocked prone, or take half as much damage on a success.

At Higher Levels: When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 2d6 for each slot above 2nd.