Capsize + Sapphire Medallion

[sdematt]

Question for you, since this just happened on MWS.

Opponent has 2 Sapphire Medallions in play, and Capsizes a permanent of mine. Does he pay 5 in total, or 4?

I argued that Medallions reduce the cost of Capsize to UU, then you pay the buyback, for a total cost of 3UU. He argued Capsize costs 1UU + 3, which is then reduced to 2UU.

I was pretty sure you cast the spell as normal, cost reduction apply, then you buyback. Who's correct here?

-Matt

[luma]

The total cost for a spell is its mana cost (or alternative cost) plus any additional costs or cost increases, minus all cost reductions. In this case, Capsize's total cost becomes 1UU + 3 (additional cost from buyback) - 2 (cost reductions from Medallions) = 2UU in total.

The actual rule:

601.2e. The player determines the total cost of the spell. Usually this is just the mana cost. Some spells have additional or alternative costs. Some effects may increase or reduce the cost to pay, or may provide other alternative costs. Costs may include paying mana, tapping permanents, sacrificing permanents, discarding cards, and so on. The total cost is the mana cost or alternative cost (as determined in rule 601.2b), plus all additional costs and cost increases, and minus all cost reductions. If the mana component of the total cost is reduced to nothing by cost reduction effects, it is considered to be {0}. It can't be reduced to less than {0}. Once the total cost is determined, any effects that directly affect the total cost are applied. Then the resulting total cost becomes "locked in." If effects would change the total cost after this time, they have no effect.

[Valtrix]

And just to further verify that buyback is an additional cost:


702.24a Buyback appears on some instants and sorceries. It represents two static abilities that function while the spell is on the stack. "Buyback [cost]" means "You may pay an additional [cost] as you cast this spell" and "If the buyback cost was paid, put this spell into its owner's hand instead of into that player's graveyard as it resolves." Paying a spell's buyback cost follows the rules for paying additional costs in rules 601.2b and 601.2e-g.