Color Identity
Color identity determines which cards you can put in your deck. Every card in your 99 must fall within your commander's color identity. It's straightforward in most cases, but there are enough edge cases that it's worth understanding the actual rule.
The rule
A card's color identity is every mana symbol that appears in its mana cost and its rules text. Not just the casting cost. The full rules text.
A card with a white mana cost and a black ability has a white-black color identity. Both colors count.
Your commander's color identity is the set of colors found on it this way. Every card in your deck must have a color identity that's a subset of your commander's. If your commander is red-white, you can include cards that are red, white, red-white, or colorless. No blue, black, or green symbols allowed anywhere on the card.
What counts
- Mana cost — the symbols in the top-right corner
- Rules text — any mana symbols in abilities, activation costs, or triggered effects
- Both faces of double-faced cards — the back face counts too
- Phyrexian mana — the hybrid life/mana symbols. {W/P} adds white to the card's identity even if you'd always pay life
- Hybrid mana — {W/B} adds both white and black. A card with only hybrid white-black mana has a white-black color identity, not a choice
What doesn't count
- Reminder text — text in parentheses that explains a keyword. Extort has white-black mana symbols in its reminder text, but those don't add to color identity. Crypt Ghast is mono-black.
- Color indicators — the colored dot on some cards (like the back face of a DFC without a mana cost) doesn't affect color identity. Only mana symbols matter.
- Produced mana — if a card says "add {G}" but has no green symbols in its cost or abilities, its color identity doesn't include green. Exotic Orchard can go in any deck.
Colorless identity
Commanders with no colored mana symbols (Kozilek, Ulamog, most Eldrazi) have a colorless identity. Your deck can only contain colorless cards and basic Wastes. No colored mana symbols anywhere.
This is restrictive but playable. Colorless decks rely on artifacts and Eldrazi for everything.
Lands
Lands have no mana cost, so their identity comes entirely from their rules text.
- Rogue's Passage — no colored symbols in its rules text. Colorless identity. Goes in any deck.
- Sunhome, Fortress of the Legion — has a red-white activation cost. Red-white identity. Only goes in decks that include both red and white.
- Command Tower — says "add one mana of any color in your commander's color identity." No colored symbols. Colorless identity. Goes in any deck.
Common gotchas
Phyrexian mana always counts. Birthing Pod has {G/P} in its cost. It's green, even though you can pay 2 life instead. Can't go in a non-green deck.
Hybrid mana is both colors. Deathrite Shaman costs {B/G}. Its color identity is black-green. You can't put it in a mono-black deck.
Extort doesn't count. The reminder text for extort shows {W/B}, but since it's reminder text, it doesn't add to color identity. Pontiff of Blight (mono-black mana cost, extort) is mono-black.
Back faces count. Archangel Avacyn is white on the front and red on the back. Her color identity is red-white.
In practice
Most of the time this is simple. Look at the mana symbols on the card. If any of them are outside your commander's colors, you can't use it. The edge cases above cover the 5% of situations where it's not obvious.