Rulings

• Casting Eidolon of the Great Revel doesn't cause its own ability to trigger. It must be on the battlefield when the spell is cast for its ability to trigger.2018-03-16
• The amount of mana spent to cast a spell doesn't change its mana value. For example, a card cast with its morph ability has a mana value of 0 even though {3} was paid.2018-03-16
• The mana value of a spell with {X} in its mana cost includes the value chosen for X.2018-03-16