Cost Alternative

Covers spells templated with "rather than pay this spell's mana cost" or equivalent alternative-cost wording, where the controller pays something else, sacrificing lands, exiling cards from hand, returning permanents, or having an opponent gain life, instead of the printed mana cost. Canonical examples include Fireblast sacrificing two Mountains, Gush returning two Islands, Force of Will exiling a blue card and paying 1 life, and Commandeer exiling two blue cards. Broader than cascade.free_spell, the narrower subset whose alternative cost lets the spell be cast without spending mana. Distinct from cascade.discover, which exiles and casts a lower-cost card off the top of the library rather than altering how a card in hand is paid for.