Counterspells interact with spells on the stack, preventing them from resolving if successfully countered. They're most closely associated with blue and allow a player to stop a threat before it ever reaches the battlefield or produces its intended effect.
Swan Song trades broad coverage for exceptional efficiency, while Arcane Denial replaces the countered spell with cards later. More specialized options such as Negate let a deck tailor its countermagic toward the threats it expects to face.
