Touching cards means having a pair of identical cards. When someone plays the same cards, they can touch them.
Mahjong originated from Guangdong, Hong Kong and Macao in China, commonly known as sparrow. It is a game and entertainment appliance invented by ancient people in China. Generally, it is a small rectangular box made of bamboo, bone or plastic with patterns or words engraved on it. Each mahjong deck in the north has 136 cards, and there are eight more cards in the south, namely, spring, summer, autumn and winter, plum, bamboo, orchid and chrysanthemum, totaling 144 cards.
Extended data:
In the late Ming and early Qing dynasties, while the horse brand prevailed, an entertainment device called "playing cards" was derived from the horse brand. There were 60 cards at first. When playing cards, four people each take ten cards first, and then take cards and play cards in turn. One family plays cards, and two or even three families say at the same time that the first one to get the card wins. These items and playing methods are very similar to today's mahjong tiles. This card game is always silent in the process of playing, so it is also called silent card.
On April 20 17, the International Intellectual Sports Federation announced that mahjong had officially become the world intellectual sports event.
References:
Mahjong Game-Baidu Encyclopedia