Spellstutter Sprite
Creature — Faerie Wizard
Flash
Flying
When this creature enters, counter target spell with mana value X or less, where X is the number of Faeries you control.
Christopher Moeller
Magic Online Promos (PRM)
• #39622Rulings
The value of X needs to be determined both when the ability triggers (so you can choose a target) and again when the ability resolves (to check if that target is still legal). If the number of Faeries you control has decreased enough in that time to make the target illegal, Spellstutter Sprite’s ability won’t resolve (and the targeted spell will resolve as normal).
(wotc • 2007-10-01)
Rulings
The value of X needs to be determined both when the ability triggers (so you can choose a target) and again when the ability resolves (to check if that target is still legal). If the number of Faeries you control has decreased enough in that time to make the target illegal, Spellstutter Sprite’s ability won’t resolve (and the targeted spell will resolve as normal).
(wotc • 2007-10-01)