The casters shadow implodes(causing no harm to caster) then sends out a ring of force, like a ripple. For every 10' it travels it does 1d2 points of damage per level of caster. exe if the ring of force hits a creature at 20 feet and the caster is 12th level that would be 24d2 points of damage. If a creature makes its save when hit it takes only 1/2 damage. All creatures wether they saved or not are pushed along by the wave. Objects of 300 lbs or greater are unaffected by pushing of the wave.