Bicolor

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Aka: Dual Color

A term used for decks that use two colors as a base for playing. Not used as often as the Monocolor and Tricolor versions. Mechanical Chaos is composed almost entirely of bicolor cards.

Bicolor, and for that matter Tricolor cards often are more expensive for their fuction. This is intentional, because multi-color cards can generally be played sooner, since the mana cost is split across more colors.