Trinisphere 
Artifact
As long as this artifact is untapped, each spell that would cost less than three mana to cast costs three mana to cast. (Additional mana in the cost may be paid with any color of mana or colorless mana. For example, a spell that would cost 
to cast costs 
to cast instead.)
Legality
standardNOT LEGALpioneerNOT LEGALmodernLEGALlegacyLEGALvintageNOT LEGALcommanderLEGAL