Call Lightning

Immediately upon completion of the spell, and once per round thereafter, you may call down a 6-foot-wide, 30-foot-long, vertical bolt of lightning that deals 3d6 points of electricity damage. The bolt of lightning flashes down in a vertical stroke at whatever target point you choose within the spell's range (measured from your position at the time). Any creature in the target square or in the path of the bolt is affected. You need not call a bolt of lightning immediately; other actions, even spellcasting, can be performed first. Each round after the first you may use a standard action (concentrating on the spell) to call a bolt. Each time you cast a bolt, the spell's duration is reduced by one minute.