Edison format ruling
Cup of Ace

Card effect (current official text)Toss a coin: ● Heads: Draw 2 cards. ● Tails: Your opponent draws 2 cards.
Rulings
- You cannot activate Cup of Ace if you or your opponent has 1 or fewer cards remaining in the Deck.
- Tossing a coin is not a cost. The coin is tossed when Cup of Ace resolves.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Edison forum — sourced change requests get reviewed.