The original rules of Mahjong are Chinese, but every country where the game is played has adapted them to suit its own ideas. Official British Rules are very similar to the original Chinese. Most of the Chinese rules have also been adopted unchanged, but there are some extensions and some restrictions. These are shown italicised and inset in the following description. Real Mahjong is based on official British Rules and should make sense to both British and Chinese players. It also allows you to select a subset of the rules approximating to Chinese rules, to use the full British Rules, or to turn individual rules on or off according to your preferences.
Chinese and British Rules
Each player represents a ‘Wind’ (East, South, West or North). Before the game starts there’s a lot of rigmarole about allocating players to Winds and shuffling the tiles. In an online game this can all be dealt with automatically by the computer (as it is in Real Mahjong) so we’ll just ignore it!
At the start of the game players are dealt thirteen tiles each, except for East Wind, who receives fourteen, and the remaining tiles are arranged in a ‘Wall’. Fourteen of the Wall tiles are reserved in a ‘Kong Box’.
The object of the game is to form a ‘Mahjong’ hand — or as Mahjong players say, to ‘go out’ or to ‘go Mahjong’. A Mahjong hand is either a Special Hand or four sets of three or four tiles and one pair. A set is called a Chow if it consists of three consecutively numbered tiles of the same rank, a Pung if it consists of three identical tiles, and a Kong if it consists of four identical tiles.
East Wind always starts a hand by discarding one of his or her 14 tiles. Any of the other players that can use the tile to complete a set other than a Chow can claim it. South Wind, who is next after East can also claim it to complete a Chow: only the player following the discarder can claim Chows.
British rules allow each player a maximum of one Chow.
If no player claims the discarded tile South Wind now draws a tile from the Wall and discards either that tile or one from his or her hand. South is followed in the same way by West, West by North, North by East, and so on. Unclaimed discards are placed in a heap. Players differ on whether they should be placed face down or not. Real Mahjong places them face up in an area where they are visible to all players, on the grounds that Mahjong is supposed to be a game of luck and skill, but not a test of memory. Some people would no doubt disagree!
This sequence is only interrupted when a player other than the one after the discarder claims a Pung, a Kong, or Mahjong.
That’s the essential structure of the game. You also need to know that when a set is formed by ‘calling’ Chow, Pung or Mahjong, it has to be ‘exposed’ or ‘declared’ by laying it down where all the players can see it. Of course in an online game such as Real Mahjong this is handled automatically.
Concealed sets and Conversions
As well as forming sets by claiming discards, you will sometimes draw a tile from the Wall or Kong Box and find that it completes a set in your hand. Unless this is a Kong you needn’t (and normally don’t) declare it, so no one else knows you have it. The exception to this is concealed Kongs. These have to be declared (though not necessarily immediately) since they use up four rather than three tiles and the fourth has to be replaced. (If you find this a bit confusing just take my word for it!) When you declare a Kong you draw a tile from the Kong Box (not from the Wall) and then choose one to discard. The Kong, although declared, is still regarded as ‘concealed’ for scoring purposes.
If you draw a tile that matches a Pung you have already declared, you can use it to ‘convert’ the Pung into a Kong. In this case however it’s an exposed Kong. Note that you can only convert a Pung to a Kong using a drawn tile: you cannot use a discard. Having converted the Pung to a Kong you must then draw another tile from the Kong Box and make a discard.
At the end of a hand a concealed set is worth twice as many points as it it would have been worth had it been exposed.
Flowers and Seasons
Four of the tiles in a Chinese or British Mahjong set are ‘Flower’ tiles, and four are ‘Season’ tiles. They are known collectively as ‘bonus tiles’ and add to your basic score, and in some situations double it.
You never discard bonus tiles. The only way you can obtain them is by drawing them from the Wall or the Kong Box. Whenever you draw a bonus tile you must declare it immediately and draw another tile from the Kong Box.
Bonus tiles are not used in Chinese Rules, nor in high-level expert play under British Rules. Real Mahjong allows you to decide whether to include or exclude them.
Washouts and Goulash
The official British Rules stipulate that if a hand ends in a ‘washout’ (i.e. no one goes Mahjong) it will be replayed according to ‘Goulash’ rules. These are designed to make it very unlikely that the hand will end in another washout.At the start of a Goulash hand each player exchanges three tiles with the opposite player (East with West and South with North). Each player then exchanges three tiles with the player to his or her left, and then with the player to his or her right. (In American rules this procedure is known as ‘The Charleston’.) The hand then continues almost as normal, but the Two Bamboos (or Joker tiles in some variants) are ‘wild’ and can be used as any tile.
Real Mahjong handles Goulash automatically, allowing you to select the tiles to exchange and to use wild tiles to complete sets of different denominations.
Rotation and Prevailing Wind
At the end of each hand each player moves to the next Wind in sequence (East to South to West to North) unless the hand was won by East Wind.
An important concept in tournament Mahjong is that of the ‘Prevailing Wind’. This starts off as East Wind, and when each player has played each of the Winds, the Prevailing Wind rotates in the same sequence. When each player has played each Wind for each Prevailing Wind the game is over.