Money-suited cards
Chinese playing cards were long, narrow strips of paper, often decorated with figures from popular novels such as The Water Margin. The best-known decks were "money-suited": their suits represented coins, strings of coins and multiples of ten thousand coins. These deck designs appeared in the Ming dynasty and remained popular for centuries.
The numbering, typically one to nine within each suit, maps directly onto mahjong's three suits. Many old mahjong sets even show Water Margin characters on their flower tiles, a visual echo of the card tradition.
Madiao
Madiao ("hanging horse") was a four-player game played with a forty-card money-suited deck, popular among literati in the late Ming. It was a trick-taking game, rather like a distant cousin of bridge, with complex scoring that rewarded particular combinations of cards.
Madiao is not mahjong, but it established a four-player structure, a ranked money-suit deck and a culture of scoring combinations. Its terminology and seating customs influenced later games.
Drawing-and-discarding card games
By the eighteenth and nineteenth centuries, players in southern and eastern China were using money-suited cards for rummy-like games in which they drew from a pack and discarded to form sets. Games of this kind, sometimes grouped under names like pengpai, used claims called "peng" for triplets — the origin of mahjong's pung.
These are the closest direct ancestors. Move such a game onto tiles, add winds, dragons and flowers, and you are very close to early mahjong.
Why the change to tiles stuck
Tiles were sturdier than paper cards, could be stood upright on the table, and gave the game a physical presence that cards lacked. Bone-and-bamboo dominoes were already familiar, so workshops could produce the new pieces easily.
The card games did not disappear immediately, and some survive in regional forms today. But by the early twentieth century the tile game had become the dominant member of the family.
