You cause the ground in a 60-foot cone to break into gravel and begin rolling and tumbling violently. Until the spell ends, ground in the area is sliding and roiling, making it difficult terrain. When the spell begins, each creature standing in the area takes 2d4 bludgeoning damage and must succeed on a Dexterity saving throw or fall prone. A creature that enters the area or ends its turn there takes 2d4 bludgeoning damage and must also succeed on a Dexterity saving throw or fall prone.

In addition, whenever a creature falls prone within the area or ends its turn while prone within the area, it takes 6d4 bludgeoning damage. This spell treats creatures that are permanently immune to being prone as if they are always prone instead.

This spell only affects creatures that are on the ground.