Card
Disrupting Shoal
Instant — Arcane · MV 2.0
Oracle text
You may exile a blue card with mana value X from your hand rather than pay this spell's mana cost. Counter target spell if its mana value is X.
Rulings
2018-12-07 · If a card in your hand has {X} in its mana cost, X is considered to be 0.
2018-12-07 · If a spell has {X} in its mana cost, include the value chosen for that X when determining the mana value of that spell, even if it was cast for an alternative cost and no mana was spent on X.
2005-02-01 · Disrupting Shoal can target any spell, but does nothing unless that spell's mana value is X.