Blast

You choose a point within 150 feet, and a powerful blast of force explodes from that point. All characters affected must make a Strength saving throw or take 8d6 force damage be knocked prone by the blast, on a successful save the character is not knocked prone and takes only half damage. Loose objects weighing less than 500 pounds are also knocked back 20 feet.

At higher levels - for each level above 3rd you cast this spell, the damage is increased by 1d6.