The druids are master of the earth itself. Upon command, they can
cause the ground to shake and split apart and engulf their foes. This not
only damages them from the flying rocks and debris, it also is a very
disruptive experience. It's hard to keep your thoughts straight when the
ground beneath you is being ripped apart. Chances are, any spell you were
weaving, or skill you were attempting to execute will be lost in the
tremors.