Moonbeam

Casting Time: 1 action
Range: 120 ft.
Duration: Concentration, up to 1 minute
A beam of light shines down in a 5-ft. radius,
40-foot-high cylinder centered on a point within
range.
When a creature enters the spell's area for the
first time on a turn or starts its turn there, it
must make a Constitution saving throw. It takes
2d10 radiant damage on a failed save, or half as
much damage on a successful one. PHB, pg. 261