Magic stone

Magic stone is a transmutation spell that turns three nearby stones into projectiles.

Effect
You transmute up to three pebbles, which can be no larger than sling bullets, so that they strike with great force when thrown or slung. If hurled, they have a range increment of 20 feet. If slung, treat them as sling bullets (range increment 50 feet). The spell gives them a +1 enhancement bonus to attack and damage rolls. The creature using the stones makes a normal ranged attack to use a magic stone. Each magic stone that hits deals 1d6+1 points of damage (including the enhancement bonus). Against undead creatures, this damage is doubled (2d6+2 points).