Tax Effect

Persistent permanents whose static abilities make opponents pay extra mana to cast spells, attack, or otherwise act. Sphere of Resistance and Trinisphere inflate every spell's cost; Thalia, Guardian of Thraben and Vryn Wingmare tax noncreature spells; Ghostly Prison taxes attackers. The shared mechanism is an ongoing additional-cost or floor on cost that throttles opponent tempo without outright forbidding the action. Narrower than control.stax, which denies resources through untap, sacrifice, or full lockdown rather than cost inflation. Distinct from control.casting_restriction, which flatly prohibits certain spells rather than charging extra, and from control.rule_of_law, which caps spells-per-turn. Cards like Grand Arbiter Augustin IV that both reduce your costs and tax opponents still belong here for the tax half.