Mana source

Mana source is an obsolete card type that was only found on Culling the Weak and Dark Ritual, as well as the non-tournament-legal Blacker Lotus and Jack-in-the-Mox, beginning with the printing in Mirage until Urza's Saga. All mana sources would have been interrupts under pre-Mirage rules, and are now instants. Abilities that were played as mana sources were previously played as interrupts, and are now mana abilities.

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