At the beginning of the game, there will be a set of cards (usually an even number) placed face down on the table or game interface. The patterns or contents of these cards are identical in pairs. Players need to turn over two cards in turn and check the content on the cards. If the patterns of the two cards turned over are the same, then these two cards are successfully paired and can be removed. If the patterns of the turned cards are different, the cards need to be turned face down again, and then continue the next round of card flipping attempts. The goal of the game is to successfully pair all cards in as few attempts as possible.