Yes (and no) Classic mode uses a standard 52 card deck, including 4 of each card 2 through Ace. Quest mode sometimes uses smaller decks, but they are taken from a standard 52 card deck, so you would never see more than 4 of the same card in either of those modes. In Battle mode, each player has a set of 26 cards taken from a standard 52 card deck, so each player’s deck would consist of at most 4 of the same card.