You release a wave of chaotic energy from yourself.  All creatures within 20 feet of your position must succeed on a wisdom saving throw.  All targets take 8d6 force damage on a failed save, and half as much on a successful one.  If no targets fail the save, the caster takes 2d6 force damage.

Casting at higher levels:

when casting this spell at 5th level or higher, both damage calculations increase by 2d6 per level above 4th.