Ùzje Mahjong

Ùzje mahjong is a mahjong variant that is designed primarily for my conworld, Ùzje. It is supposed to be a combination of a number of other variants, along with a number of idiosyncratic changes that are there just to be difficult. This document is not a complete document of Ùzje mahjong, but rather a list of key differences that distinguish it from other variants. In general, you should be able to play the game if you have this document and some knowledge of either Riichi mahjong or HKOS.

A full document that describes the game from start to bottom is planned. Additionally, a game engine is being written for computers to play (and eventually, humans).


  • Four-player by default, can go up to six players or down to three. The remainder of this document assumes a four player configuration unless indicated otherwise.
  • Requires a table with a flat surface, should be felted to reduce noise but can be done on any sufficiently large square table
  • Tiles (described below), 3d6
  • Optional: score sheet, chips, current wind indicator
  • Fancy tile-shuffling tables are cool but not necessary
  • Tiles

    Like most variants, contains five suits: circles, bamboos and characters as "number tiles"; winds and dragon tiles as "honour tiles"; eight "flower tiles". Idiosyncratic names are in place however:

    | English    | UJMJ    |
    | Circles    | Tongs   |
    | Bamboos    | Socks   |
    | Characters | Mans    |
    | Winds      | Winds   |
    | Dragons    | Arrows  |
    | Flowers    | Flowers |

    Special notes for materials:

  • Unlike all other variants, the number tiles go all the way up to 16.
  • For a four-player game, the tongs are limited to the terminals, 1 and 16.
  • Choose to play with either the normal complement of wind tiles, N, E, S and W, or a compressed set of wind tiles, H and V. When one uses compressed tiles, H stands for W and E and will become the most useful one of the two to complete a hand, and similar for V with N and S.
  • Choose whether to play with flowers. Either all eight flowers are used or none are.
  • Images of every tile that can be used in the game 🖼️

    Images of every tile that can be used in the game


    An ASCII-compatible notation system exists for tiles and sets of tiles. Because of the extended tile set, the Unicode characters are not enough.

    It is easier to explain the honour tiles first. Simply make the following substitution:

    E East

    S South

    W West

    N North

    H Horizontal

    V Vertical

    C Red

    F Green

    P White

    Zero is a special tile. As it is an honour tile of any suit and a number tile depending on what is convenient, it is notated Z when it is an honour and 0 when it is used as a number tile.

    The flower tiles use lowercase letters:

    h Spring

    i Summer

    j Autumn

    k Winter

    o One

    p Two

    q Three

    r Four

    Number tiles use two characters. The first character represents the rank. Use 1 ~ 9, then x, then a ~ f for 1 to 16. The second character is the suit:

    t Tong

    s Sock

    m Man

    When two or more number tiles with the same suit are sorted together, then all but the last suit character can be omitted. For example, 9, 10 and 11 of sock put together are 9xas. When a zero is used as a number tile, it is written 0 followed by an appropriate suit letter.

    This notation should be easy to parse context-free, as there are no characters that are terminal and non-terminal at the same time.

    Conventionally, tiles are sorted in this order: tongs, socks, mans, zero, winds, arrows. The number tiles are internally sorted by their rank. Flowers are sorted in alphabetical order from their notation as above, but they aren't comparable to any other tile; they are always by themselves.

    Game start

    Wall building

    To start the game, shuffle the tiles as usual. Then build the walls, two tall, one deep, and this wide:

    | Base width              | 20 |
    | Using full set of winds |  1 |
    | Using flowers           |  1 |
    | Using all tongs         |  7 |
    | Maximum width           | 29 |

    In other words, the default width is 22 with flowers and 21 without flowers. Needless to say, the tiles are noticeably smaller.

    As with most variants, each player builds one wall, and then pushes the right end towards the centre of the table. This should make a T shape on the right of each player.

    Breaking the wall

    HKOS rules mostly apply, with some Riichi elaboration:

  • Designate some starter player
  • He rolls 3d6 (alternative: use 1d20 instead – more common with modern players)
  • The player on his left is 0, and increases anticlockwise – from all players' lefts to their rights
  • The player corresponding to the rolled value (mod 4) then counts starting from the right end of his wall, the one with the T, and counts left that many tiles. At the tile he counted to, push the next tile over to form a gap. This is the break point. He is also the dealer, and the starting dealer.
  • Players take the tiles, four at a time, in the same way as in common variants of mahjong. The dealer should have 14 tiles and everyone else 13.
  • The dealer then counts /right/ from the break 16 tiles, or 8 stacks. Continue past the wall boundary as with Riichi. Create a second break to the right of the 8th stack. The small wall is now the "dead wall", just like in Riichi but significantly larger. However, tiles are permanently stuck here; "rinshanpai" are all in the live wall.
  • Flip over the tile on the top leftmost stack. This is the designated bonus tile of the game.
  • At this point, the game can start normally.

    Main game

    Standard turn

    At the start of a turn, the player to play has 14 tiles in his hand. He could have gotten the tile from a number of sources, which we will describe later, but the player with 14 tiles is always the one who is to play next. At this point, the player has the following choices he can make; however, not every choice is available to him all the time:

  • If there are any flowers in the hand, then expose those flower tiles and set them aside. This is mandatory for every flower tile. Then draw a tile from the far end of the all and continue with the following steps.
  • If the tiles he has constitute a sufficiently valuable winning hand, he can "go out" and claim a win. He opens up all fourteen of the tiles to show all other players the hand for verification. After that, the players score the hand and exchange points accordingly.
  • If he got the tile from someone else, for which see "claiming a tile to complete a meld" section below.
  • Otherwise, if he has four tiles all the same (a quad), he may choose to reveal that he has a quad and then set them aside as a completed meld. To do that, see "Declaring a closed quad" section below.
  • Finally, discard a tile (see "discarding a tile" below).
  • Below are some specific procedures that occur on some turns.

    Claiming a tile to complete a meld

    If a tile is claimed from some other player, it must be to complete a meld.

  • For a trip or a quad, he could have gotten it from any other player.
  • For an arith, he must have gotten it from the player to his left.
  • In either case, he must display the meld to all other players to verify that he has the meld. The meld is then set aside on the left (n.b. not the right, as in Riichi) of the player. Like in HKOS but not in Riichi, all tiles are upright relative to the player, and never put sideways for any reason.

    If the exposed meld is a quad, then do the following:

  • Draw a tile from the end of the wall
  • Flip up the next tile in the dead wall
  • Go back to the beginning of the standard turn
  • The next tile in the dead wall is the tile to the left of the leftmost exposed tile. If there are no tiles to the left of the leftmost exposed tile, then push all the tiles on the top over to expose the bottom of the stacks, and open the rightmost tile on the newly exposed set of tiles. In the extremely unlikely event that all tiles are exposed, which can only happen when a player opens the sixteenth and final possible quad in the game, skip the step and continue as normal.

    Declaring a closed quad

    There are two types of closed quads, one of which must be selected as the one to use before the game starts:

  • The identity of the tile is hidden from other players. In this case, all four tiles are placed face-down when melded.
  • The identity of the tile is known to other players. In this case, all four tiles are opened for players to verify that they are indeed the same tile. After that, two tiles are flipped over again, and the four are put aside in the melded area.
  • In the case where the identity of the tile is hidden from other players, a player can challenge the quad, at which point the player must open the quad anyway for verification. After verification though all four tiles are then turned over face-down again and set aside in the meld list. A player can only challenge another player's quad on the second quad that the latter forms and onward.

    When the game ends, all tiles in every quad are flipped back up to ensure that all four tiles are indeed the same.

    Discarding a tile

    Discarding a tile is as with all other games. A tile is exposed and then placed into a public pool where everyone can see it.

    The way the tile should be discarded is different from all other variants. There is only one discard pile, unlike in Riichi, but the tiles are discarded in a particular way: they must be sorted in the standard tile order, starting from 1t, ft, 1s, 2s, ..., fs, 1m, ..., fm, Z, E, S, W, N, C, F, P. Flowers cannot be discarded so they do not appear in this list. They are stacked, two tall (so each tile would appear twice from top-down if they are all discarded) and facing the dealer – the 1t should be on the corner between the dealer's opposite and left player, and the P between the dealer and his right player. In the early stages, the tiles can be placed in a rough position as it is not easy to sort them properly; however, players are expected to arrange the discarded tiles so that they can be seen to be in sorted order as the game progresses.

    A discarded tile may be left alone, in which case the next player, who is the one to the discarder's right, picks a tile from the wall. Otherwise, a player may claim the tile:

  • For an arith, only the player on the discarder's right can claim it. This is a "chow".
  • For a trip or a quad, any player can claim it, skipping all other players' turns. This is a "pung" or a "kong", respectively.
  • For a win, any player can claim it, and go out. Players score the hand and exchange points.
  • Wins trump trips and quads, which in turn trumps ariths. There are only four copies of a single tile, so two trips or two quads cannot happen on the same tile.

    Unless a win is declared, another player now has 14 tiles instead of 13. From here he follows the step above.

    End of game and game structure

    When someone goes out, that is the end of a game. Like in most traditional variants, there is a hierarchy of games and a full "game", in terms the journey from start to end of human interaction, will include many such games.

    While the structures are the same, in Ùzje mahjong the names are altered to add a completely unnecessary tennis analogy. Well, unnecessary for native players; the outsiders certainly need it:

  • Game: A game is the time of play between when the tiles are first shuffled until when someone either goes out or the wall runs out of tiles. All "end of game" procedures refer to the end of this definition of game.
  • Set: Whenever someone other than the dealer goes out, the prevailing wind ("game orientation", in UJMJ terminology) rotates over. The time of play between when the first dealer of the game gets East wind to when the next time when the first dealer of the game gets East wind again /after losing it first/ is a set. At minimum, a set contains four games; however, if there are goulashes or any player wins as dealer then there will be more games.
  • Match: Each set has a wind (the "set orientation") which starts at East in the beginning of the game and goes clockwise after each set is completed. Therefore, after four sets the set orientation is East again. The time between when these two events happen is a match.
  • The full time, from start to end of human interaction, is called a "game", for lack of a better name. If required, it can be disambiguated to terms such as "a full game".

    The typical full game is one match long. For a shorter experience, a ½-match (i.e. 2 sets) may be used. In any case, because most bouts are one match long, it can also be called a "match".

    Terminology here are based on GMF. The MQY names for these things are similar but different in small ways, in particular the MQY terms closely mirror Riichi terms, with "場" "局" "圈" "h東" being used, corresponding to game, *, set and match. The second character is used to represent the period of time a game orientation stays the same. It is not indicated in GMF.

    A full game should end only at the end of a set, unless it is a single game long. This is a general tradition and nothing structurally different happens on a game-to-game basis, but it allows everyone a chance to be a dealer for a fixed and constant number of times if followed.

    Some tournaments do not do sets and only have a fixed number of games for a match.


    All players start with 0 points. Scoring is reset at the start of a full game, and exchanged into whatever tournament scoring system is in play (which can include literal monetary amounts).

    Scoring is based on the number of fans that one has above the minimum required to win:

  • A hand that has the bare minimum to win gets a score of 2 points.
  • Each fan above the minimum pushes the score up the next sequence of the 1-2-5 preferred numbers.
  • A limit hand is scored as a fixed amount, typically worth the equivalent of 13 f. Multiple limit hands are added together normally rather than continuing the sequence. If a hand has a pattern scoring a limit hand, then no fan are considered at all.
  • Otherwise, if the score exceeds the amount that one limit hand is worth, it is capped to one limit hand. Every third additional fan after the limit hand has been reached is worth one additional limit hand; the rest are discarded.
  • For example, given that the threshold is 2.5 f:

    3 f ⇒ 2 pt

    4 f ⇒ 5 pt

    5 f ⇒ 10 pt

    6 f ⇒ 20 pt

    7 f ⇒ 50 pt

    8 f ⇒ 100 pt

    9 f ⇒ 200 pt

    10 f ⇒ 500 pt

    11 f ⇒ 1000 pt

    12 f ⇒ 2000 pt

    13 ~ 15 f = 1 l ⇒ 5000 pt

    16 ~ 18 f = 2 l ⇒ 10 000 pt

    19 ~ 21 f = 3 l ⇒ 15 000 pt

    22 ~ 24 f = 4 l ⇒ 20 000 pt

    The exact payments to the winner is slightly different depending on how the winner won the game:

  • In the case where the winning tile is from another player, that player must pay the corresponding amount to the winner.
  • In the case where there are multiple winners, the losing player must pay each one that amount.
  • In the case where the winning tile is drawn by the winner, all other players pay exactly half of the amount in the above table, which means in particular that a 7 f hand won by self draw would have the other players pay 25 points (not 20), and the winner receives 75 points.
  • The last point is why the minimum amount to win is worth two points and not one.

    Hands – General structure

    A winning hand, in general, must contain four melds and a pair. This is fairly standard across all variants, and the exceptions are also fairly standard, though the expanded number tiles do expand some options.


    As its name suggests, a pair are any two identical tiles. Pairs cannot be melded, and in fact are not normally considered to be a type of meld. One must appear in any winning hand, except for the Fourteen Orphans, and they are useful for creating melds, so it's necessary to recognise them.


    A trip is a meld of three identical tiles.


    A quad is a meld of four identical tiles. There are four copies of each tile, so that means that it has all copies of a particular tile.

    Despite being four physical tiles, it is still a meld and therefore logically counts as three tiles.


    An arith are three number tiles in an arithmetic sequence. An arithmetic sequence is a generalisation of the traditional "sequence", which is an arith with a difference of 1. Valid examples of ariths include 369s, 5xet and xcfs.

    Zero can participate as an arith in either suit.


    Short for "geometric sequence", a meld consisting of the following ranks in a single suit:

  • 124
  • 248
  • 48f
  • 139
  • Zero cannot participate as part of a gem.


    A meld consisting of the following ranks in a single suit:

  • 014
  • 149
  • 49f
  • 018
  • These are the successive square numbers and cubic numbers.

    Special forms

    Thirteen/Fourteen orphans

    The classical thirteen orphans pattern exists in UJMJ. As a recap, the hand consists of thirteen classical terminals, and one more of any of the pair. The thirteen classical terminals are 1ft1fs1fmNESWCFP.

    However, there are in fact fourteen terminals in UJMJ, because zero is a terminal in this case. Therefore, a better hand consists of having one of each of the terminals: 1ft1fs1fmZNESWCFP.

    When playing with compressed wind tiles, EW has to be replaced with HH and NS is replaced with VV.

    Seven pairs

    Seven pairs of any tile is a winning hand. As a result of its form lacking any melds, this cannot be opened. While four identical tiles counts as two pairs, a quad cannot count as two pairs if they are melded.

    Ultra-long straight

    For the same suit, collect 123456789xabcd, 23456789xabcde, or 3456789xabcdef. This hand may be open but it cannot /all/ be open; in this case, all open melds must be ariths with a difference of 1 (i.e. a traditional sequence).

    Standard forms

    All other winning forms must follow the four melds and a pair pattern as described above, and to win they must be sufficiently valuable. The value of a particular hand is scored in units of "fan" and the minimum to win is 2.5 fan (abbreviated as 2.5 f). Fan can only be earned in increments of 0.2 fan, so there is no question of what happens at exactly 2.5. While the limit can be altered up and down it should always be a half-integer, precisely to avoid dealing with borderline cases.

    Scoring of these fan are *provisional* and are subject to change with play testing, except for those prefixed with =. Nevertheless, they do exist because they are generally available across most ordinary variants of mahjong (here specifically excluding the highly divergent American variant of the game, and not even the tile-matching type).

    The American variant, for reference

    A regexp is given as a sanity check wherever possible. It operates on the ASCII tile string, as described above, and assumes that there are 14 tiles, excluding flowers, and they are in the canonical sorted order.

    They are sorted by category, with each form prefixed with a ### .

    Luck-based wins


  • Take the winning tile off the wall
  • Always available, even if your hand is open
  • = 1 f
  • Closed hand

  • No tile was in an open meld when the win is declared
  • The winning tile can be from another player, or self-drawn
  • If self drawn, then combine with Self-draw above.
  • 2.6 f
  • Key points for score adjustments:

  • Closed hand + self-draw must always be winnable
  • Closed hand /should/ be winnable with minimal other effort
  • Sea-scoop

  • Win from the last available tile from the wall
  • This last tile can be from an ordinary draw, or as a draw from the "other side" because of a quad.
  • Will stack with either of these cases
  • 1.8 f
  • + 3 f if the drawn tile is a 1t
  • Pond-scoop

  • Win from the last discarded tile
  • 1.2 f
  • + 3 f if the drawn tile is a 3m
  • Quad draw

  • Win the tile drawn because of a quad
  • 1.6 f
  • + 3 f if the tile is a 5t (and the 5t is in play)
  • Multi-quad draw

  • Draw a tile from a quad, and then form a closed quad, and then win off that drawn tile
  • The closed quad need not be of the tile drawn the first time
  • 5 f
  • + 3 f for each extra closed quad formed after the second one
  • + 3 f if the tile to win on is a 5t (and the 5t is in play)
  • Quad rob

    Standard variation:

  • Win on a tile that someone else used to make a quad from a melded trip
  • Cannot win off a concealed quad, no matter which concealed quad rule is in place
  • 2 f
  • + 3 f if the tile is 2s
  • Special rule for thirteen and fourteen orphans:

  • Win on a tile that someone else used to form any quad whatsoever
  • May challenge any totally concealed quad, if playing with fully concealed quads
  • No extra score
  • Lucky tiles

    Bonus tile

  • A tile in the hand or melded matches the tile in the bonus box (as Riichi rules)
  • Stacks on each one
  • 0.6 f each
  • Are "normal fan", e.g. having 5 bonus tiles is enough to win on an otherwise scoreless hand if the threshold is set at 2.5 f.
  • Flowers

  • Have a flower tile matching your seat
  • "Matching" as per HKOS rules
  • Orchard

  • Get all four tiles in a single set of flowers
  • Supersedes "Flowers"
  • 3 f
  • hijk|opqr

    Six flowers

  • Get six of the eight flowers
  • Supersedes "Flowers" and "Orchard"
  • Win regardless of the form of your hand
  • Must be won on receipt of the sixth flower; cannot be claimed again afterwards
  • = Always valued at the minimum amount needed to win
  • Ivies on the Wall

  • Have seven flowers melded
  • Win on the last flower melded by anyone else
  • 8 f
  • Crossing the sea

  • Get all eight flowers by drawing them
  • Win regardless of the form of your hand
  • 1 l
  • hijkopqr

    Special tiles

    Seat wind

    Round wind

  • As Riichi and HKOS
  • = 1 f each
  • Arrow tiles

  • As Riichi and HKOS
  • = 1 f each

    Limited tile choice

    Clean Socks / Clean Mans

  • All melds are either honour tiles or a single number suit.
  • The number suit is not tongs, if the abbreviated tongs is used.
  • [0-9xa-f]+[ms][NESWZCFP]+

    Clean Tongs

  • As above, but the number suit is tongs.
  • Worth more than one suit and honours.
  • Always overlaps with "Rock field"
  • Not used when all tongs are in play
  • [1f]+t[NESWZCFP]+


  • All melds are from a single suit
  • [0-9xa-f]+[tsm]

    Single differences

  • All melds apart from the pair are ariths with the same common difference
  • 1.4 f
  • (Name T. B. D.)

  • All melds apart from the pair are powers
  • (Name T. B. D.)

  • All melds apart from the pair are gems
  • Rock field (tripping hazard)

  • All melds apart from the pair are trips
  • .{3}.{3}.{3}.{3}.{2}


  • Two melds are exactly the same as each other
  • Archery class

  • Trips of two arrow tiles and a pair of the last

    Limit hands

    Thirteen Orphans

    Fourteen Orphans

    See descriptions above.


  • Trips of all four wind tiles plus a pair of any other tile


  • Trips of three of the four wind tiles plus any other meld
  • Honourable

  • All tiles are honour tiles
  • Zero is an honour tile in this case
  • ^