Normal: You cause the ground to alter its basic form, temporarily creating natural obstacles that provide cover.

All creatures of medium size or smaller in the area gain the benefits of cover. The obstacles do not hinder movement, nor do they provide cover against adjacent foes.

Reverse: You cause the ground to alter its basic form, temporarily shrink natural obstacles that provide cover.

Objects in the area that provide total cover now only provide cover, and objects that provide cover no longer do so.