less to cast.
in its mana cost, you choose the value of X before calculating the spell's total cost.Emerald Medallion reduces the generic portion of every green spell you cast by one mana. It can help green decks cast several creatures, ramp spells, or support enchantments during the same turn, with each qualifying cast receiving its own discount. The artifact does not tap for mana, so its value depends on the spells you are actually casting.
Three Visits can cost a single green with Medallion in play, while Guardian Project becomes easier to establish before you begin casting creatures. Larger green threats also benefit as long as their costs contain generic mana. A deck that chains several green spells can accumulate more savings than a mana rock would provide from one activation.
Green Sun’s Zenith illustrates how the reduction works with X spells. Choose the value of X first, then apply the discount to the total cost. Reducing what you pay does not reduce the chosen X or the mana value of the creature Zenith can find. Finale of Devastation can benefit in the same general way while retaining its chosen value for its effects.
The reduction cannot pay green symbols, so a one-green creature such as Elvish Mystic receives no discount from its printed cost. It also does not reduce an activated ability or a colorless artifact spell. Keep enough lands and actual mana sources to support those parts of the deck. Medallion is strongest in a list with many green spells containing generic costs, especially when card draw keeps enough spells available to use the discount repeatedly.
