2020-08-07 : If a card in a player's graveyard has {X} in its mana cost, X is considered to be 0.

2020-08-07 : In a multiplayer game, if a player leaves the game, all cards that player owns leave as well. If you leave the game, any spells and/or permanents you control from Geth's last ability are exiled.

2020-08-07 : The target card must have mana value exactly X. You can't overpay to have the player mill more cards.