Counter-Spell

Counter target counter spell or spell that places
counters. Put a +1/+1 counter on target spell that
wasn't countered by a counter spell. Counters on
counter spells can be countered as long as you
have countered a counter-spell that places
counters on a non-countered spell. Permanents
cannot have counters placed on them as long as
there is a counter-spell on the stack. Counter any
counter spell that disobeys any of these rules.