Diamond MareHow it works & interactions with other cards

Choosing Your Color

Diamond Mare features a replacement effect that happens exactly as it enters the battlefield. You must choose one of the five colors of Magic: white, blue, black, red, or green. Note that 'artifact' or 'colorless' are not colors and cannot be chosen. This choice does not use the stack and cannot be responded to by opponents.

How Life Gain Triggers

Once the color is chosen, Diamond Mare gains a triggered ability. This ability triggers whenever you cast a spell of the chosen color. This trigger goes on the stack on top of the spell you just cast, meaning you will gain the 1 life before the spell itself actually resolves. If the spell is countered, you still gain the life because the act of casting was completed.

Strategic Implementation

This card is most effective in mono-colored decks or decks with a very high density of a single color. It is important to remember that Diamond Mare itself is colorless, so it will not trigger its own ability when you cast it. Additionally, if Diamond Mare leaves the battlefield and returns, you may choose a new color, but it 'forgets' the previously chosen color.

Interaction examples

Lowering Costs for More Life

Foundry Inspector

With Foundry Inspector on the battlefield, Diamond Mare costs only {1} to cast. While Diamond Mare won't trigger its own life gain, lowering the cost of other artifact spells that have a color (like colored artifact creatures) allows you to chain spells together and gain life more rapidly each turn.

Colorless Interactions

Ornithopter of Paradise

If you choose 'Blue' for Diamond Mare and then cast Ornithopter of Paradise, you will not gain life. Even though Ornithopter of Paradise can produce mana of any color, the spell itself is colorless. Diamond Mare only looks at the color of the spell being cast, not the colors of mana that the resulting permanent might produce.