Mahjong did not start out as a computer tile stacking game. The real mahjong, also known as mah jongg, is a traditional Chinese gambling game played with the same tiles shown in the stacking game. It is similar in play to card games. There are a few rule variations, particularly between Chinese style and American mahjong, which uses more tiles. These are very basic rules for playing American mahjong.
Set up the game by placing the 152 tiles face down between the players. Each player rolls the dice; the player with the highest score becomes "The East," or host, of the game. This will pass to the right for successive games.
Build a Wall of tiles, still face down, in front of each player that is two tiles high and 19 tiles wide. Each player will select tiles from their Wall.
Break the Wall by rolling the dice and counting the number rolled across the Wall starting at the right. Take the next four tiles (bottom two and top two). This process starts with the East and then is performed by the player to the right; it is performed by all four players three times so every player ends with 12 tiles.
The East takes the next two tiles in the East Wall. Each of the other players takes one from their Wall, so the East starts with 14 tiles and the other players with 13 each. Players arrange their tiles on their racks, if used.
Commence the Exchange in the following manner: each player passes three unwanted tiles to their right, then three unwanted tiles are passed among the players sitting opposite each other, and finally each player passes three unwanted tiles to the player at their left.
Begin play with the East drawing a tile from the East Wall (if using racks, then it is placed on the upper section) and discarding a tile face up into the middle. Each player is trying to complete a hand of 14 tiles (for beginning players a score sheet is necessary to recognize the hands). Order of play follows a clockwise motion.
Play continues until a player completes a hand or the Walls are depleted, in which case the game simply starts over. A player may take a tile from the face up discards if it is the last tile needed to complete a hand.