Oracle

Artifact 

As Seal of the Guildpact enters the battlefield, choose two colors.
Each spell you cast costs 1 less to cast for each of the chosen colors it is.

Tournooi-info

Legal in: Vintage, Legacy, Commander

Officiele rulings

11/4/2015
You must choose two different colors.

11/4/2015
Seal of the Guildpact’s last ability doesn’t change the mana cost or converted mana cost of any spell. It changes only the total cost you pay.

11/4/2015
Seal of the Guildpact’s last ability can’t reduce the amount of colored mana you pay for a spell. It reduces only the generic component of that cost.

11/4/2015
If there are additional costs to cast a spell, or if the cost to cast a spell is increased by an effect (such as the one created by Thalia, Guardian of Thraben’s ability), apply those increases before applying cost reductions.

11/4/2015
The cost reduction can apply to alternative costs such as evoke costs.

11/4/2015
If a spell you cast has X in its mana cost, you choose the value of X before calculating the spell’s total cost. For example, if that spell’s mana cost is XRG and you’ve chosen red and green, you could choose 5 as the value of X and pay 3RG to cast the spell.

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