Rulings

• 2017-09-29
  If the mana cost of the revealed card includes , X is considered to be 0.
• 2017-09-29
  Some raid abilities trigger at the beginning of your end step. These abilities trigger if you attacked with a creature that turn, even if the card with that raid ability wasn't on the battlefield when you attacked.
• 2017-09-29
  Raid abilities care only that you attacked with a creature. It doesn't matter how many creatures you attacked with, or which opponent or planeswalker controlled by an opponent those creatures attacked.
• 2017-09-29
  The converted mana cost of a split card, such as cards with aftermath from the Amonkhet block, is based on the combined mana cost of its two halves.
• 2017-09-29
  If the revealed card doesn't have a mana cost (because it's a land card, for example), its converted mana cost is 0.
• 2017-09-29
  Raid abilities evaluate the entire turn to see if you attacked with a creature. That creature doesn't have to still be on the battlefield. Similarly, the player or planeswalker it attacked doesn't have to still be in the game or on the battlefield, respectively.