Eureka

If the card has an X in its mana cost, treat X as zero.

In a game of N players, the process ends when all N players in sequence (starting with you) choose not to put a card onto the battlefield. It doesn’t end the first time a player chooses not to put a card onto the battlefield. If a player chooses not to put a card onto the battlefield but the process continues, that player may put a card onto the battlefield the next time the process gets around to them.

The cards are put onto the battlefield and will not trigger effects which trigger on such cards being “cast” or “played”.