Counterspell

Reactive answers cast at instant speed to counter a spell or ability while it's on the stack, stopping it from ever resolving. Covers hard counters like Counterspell and Mana Drain, conditional counters like Mana Leak and Negate, free counters like Force of Will and Fierce Guardianship, and ability counters like Stifle and Disallow. Also includes creature-bodied counters like Mystic Snake. Distinct from interaction.redirect, which changes a spell or ability's targets rather than countering it, and from interaction.cant_be_countered, which protects your own casts from being countered. Battlefield-zone effects like interaction.theft and interaction.threaten act on permanents already in play and are not stack interaction.