Asked by stevenwolph 5 years agook so lets say i have Galvanoth in play and Street Spasm is Revealed using Galvanoth ability. Now i dont have to pay a mana cost so do i get to pick how much X is worth? Ex: i pick X= 10, so i can have one creature take 10 damage or have a lot of them take 5.
No. Always check the Gatherer rulings before asking a question. From Galvanoth 's page:
6/1/2011: If the card has an X in its mana cost, you must choose 0 as its value.
Furthermore, you misunderstand how overload and double costs work.
First, overload is an alternate casting cost. So is casting something without paying its mana cost. You can only pay one alternate cost, and Galvanoth requires that you use its ability's alternate cost ("without paying its mana cost) if you choose to cast the spell. Therefore, you can't pay the overload cost.
Second, when you cast a spell with in its mana cost, you declare the value of , then you calculate the cost for the spell based on the declared value. If there are two values for a spell, must be the same for both of them. isn't divided in half. It's paid twice.