Thunderwave

Casting Time: 1 action
Range: Self (15-foot cube)
Duration: Instantaneous
A wave of thunderous force sweeps out from you.
Each creature in a 15-foot cube originating from
you must make a Constitution saving throw. On
a failed save, a creature takes 2d8 thunder
damage and is pushed 10 feet away from you. On
a successful save, the creature takes half as much
damage and isn't pushed.
See PHB, pg. 282.