Volt Charge deals 3 damage to target creature or player. Proliferate. (You choose any number of permanents and/or players with counters on them, then give each another counter of a kind already there.)
Official Rulings for Volt Charge
6/1/2011 : If the creature or player is an illegal target when Volt Charge tries to resolve, it will be countered and none of its effects will happen. You won't proliferate.