Mindbreak Trap
Instant — Trap
If an opponent cast three or more spells this turn, you may pay 
rather than pay this spell's mana cost.
Exile any number of target spells.
Sheriff Bans Rootin'—Is Tootin' Next?
Illustrated by Arik Roper
Formats
Not Legalstandard
Legalhistoric
Legaltimeless
Not Legalpioneer
Legalmodern
Legallegacy
Not Legalpauper
Legalvintage
Not Legalpenny
Legalcommander
Legaloathbreaker
Legalbrawl
Not Legalalchemy
This printing
Prices
USD$9.45
USD foil$21.36
EUR€6.41
EUR foil€12.63
MTGO3.71 tix
Rulings (3)
Mindbreak Trap's alternative cost condition checks whether an opponent cast three or more spells this turn, not whether those spells have resolved.
If a spell is exiled, it's removed from the stack and thus will not resolve. The spell isn't countered; it just no longer exists. This works on spells that can't be countered.
For Mindbreak Trap's alternative cost to apply, a single opponent must cast three or more spells. Three opponents each casting a single spell won't work, for example.
