Thorn and Teeg

[citanul]

Thorn of Amethyst
Noncreature spells cost {1} more to play.

Gaddock Teeg
Noncreature spells with converted mana cost 4 or greater can't be played.
Noncreature spells with {X} in their mana costs can't be played.

What's the interaction between these cards? Is it possible to still play a card that costs 3 mana, like Vindicate, while it now costs 4 due to Thorn?

[Skeggi]

There is no interaction. Vindicate's converted mana cost is 3, even though you have to pay 4 for it with Thorn of Amythist in play.


203.4. Any additional cost listed in an object’s rules text or imposed by an effect isn’t part of the mana cost. (See rule 409, “Playing Spells and Activated Abilities.”) Such costs are paid at the same time as the spell’s other costs.

[citanul]

Oke thanks for the quick reply.

[quicksilver]

There is no way to change the converted mana cost of a card. (the only exception being when a spell with X in the cost is being cast, then the converted mana costs varies based on what X is.)