Chain Missile

Three missiles of magical energy dart from your fingertip
to unerringly strike a creature. The missiles strike one
creature initially, then spring to other targets. Each missile
deals 1d4+1 points of force damage. Choose one target
within range, all missile created hit the first target then
ricochet. Each time the missiles ricochet they must choose a
new target not yet hit by this spell and one missile is lost, this
effect continues until there are no more missiles or no more
targets.
A shield spell stops all missiles created by this spell and
they do not ricochet.
At higher levels. For each level above 3rd you create one
extra missile when you cast this spell