You are allowed 40 cards in your deck, no more and no less. A deck is called a Library. You can only have 3 of a card name, unless the card is *restricted.* The player with 5 creatures on this 3 by 3 tile wins, which means you will never have a tie. It's only one match against your opponent. You can either have animation ON or Off in the options menu. Each time one of your monster dies, you can one mana. If you run out of cards in your Library, you lose.