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).



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:

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:

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:

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.

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:

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:

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:

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:

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:

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:

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:

Zero cannot participate as part of a gem.


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

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


Closed hand

Key points for score adjustments:



Quad draw

Multi-quad draw

Quad rob

Standard variation:

Special rule for thirteen and fourteen orphans:

Lucky tiles

Bonus tile




Six flowers

Ivies on the Wall

Crossing the sea


Special tiles

Seat wind

Round wind

Arrow tiles


Limited tile choice

Clean Socks / Clean Mans


Clean Tongs




Single differences

(Name T. B. D.)

(Name T. B. D.)

Rock field (tripping hazard)



Archery class


Limit hands

Thirteen Orphans

Fourteen Orphans

See descriptions above.





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