Japanese Mahjong yaku - AbsoluteAstronomy.com

Japanese Mahjong

Japanese Mahjong , also known as Rīchi Mahjong, is a variation of mahjong. While the basic rules to the game are retained, the variation features a unique set of rules such as rīchi and the use of dora....

, yaku (Japanese: 役) is a condition that determines the value of the player's hand. In the Japanese version of the game, a player must have a minimum of one yaku in their hand in order to legally win. Each yaku has a specific han value: for each han a hand contains, the hand's point value increases exponentially. Yaku conditions may be combined to produce hands of greater value.

(Note: this article uses only English and Japanese terms whenever possible. Terms like "chow," "pung," and "kong" are not used here, since Japanese players use different terms while playing mahjong.)

Overview

Yaku are somewhat similar to poker hands. They fit certain patterns based on the numbers or types of tiles included, as well as the relative value of those tiles. Furthermore, each yaku has a han value based on the probability of attaining the yaku. The more difficult the yaku is to achieve, the greater its value. Unlike poker, however, a hand can have more than one yaku. Thus, their han values can be combined. In fact, it is a vital strategy in mahjong

Mahjong

Mahjong, sometimes spelled Mah Jongg, is a game that originated in China, commonly played by four players...

to try and aim for hands that have several yaku together in order to increase the player’s score.

When a winning tile of a closed hand is a discard, the meld including that discard is considered open, while the hand is still regarded as closed. If a hand is closed, the situation is called "menzenchin (門前清)" or "menzen (門前)" in Japanese.

There are three basic classes of yaku:

Closed hand only (menzen-nomi, 門前のみ)
"Eat and decrease" (a literal translation of kuisagari [喰い下がり], where the han value decreases by one if the hand is open)
Yaku where the han value is the same regardless of whether the hand is closed or open.

The basic concept of a yaku is that it fits one of three basic criteria:

It contains a pattern of some kind
It has a great deal of consistency, or
It involves a great deal of luck

Finally, when it comes to scoring, the total number of han in the hand is counted. When appropriate, it is also combined a certain number of fu points. The combination of the han count and fu count corresponds to a points table.

Dora

Dora (ドラ) is a bonus tile that adds han value to a hand. Every kind of tile can become a dora tile. A dora tile adds the same number of han value as the number of its corresponding "dora indicator" tiles. Dora is not counted as yaku, and having it without yaku does not meet the 1-yaku requirement for a complete hand.

At the start of a round, the third tile from the back end of the dead wall on the upper layer is flipped and becomes a dora indicator. Then, its succeeding tile is recognized as dora. For example, if an indicator is a Green dragon (

), Red dragons (

) are counted as dora tiles (take notice of the Japanese order of dragons, in which White

becomes the first).

The succeeding order of dora is as follows:

Each time a quad is made, the adjacent tile of the dora indicator(s) is opened and becomes another dora indicator, namely, the fourth tile from the back end is flipped immediately after a player declares the first quad (i.e., before that player draws a supplemental tile from the back end of the dead wall), and the number increases in this direction in the same way. The number of dora indicators becomes five in case a single player made four quads and this is the largest amount (see Four quads).

In addition, when a player goes out with declaration of rīchi (ready hand), the tiles underneath the dora indicators are opened after the winning and become the other dora indicators, making their succeeding tiles also counted as dora which are called ura-dora (裏ドラ, underneath dora).

It is said that the name dora stands for "dragon," although it has nothing to do with dragon tiles in contemporary Japanese mahjong.

List of yaku

The following is a list of all the yaku, their names in Japanese, as well as their han values and any special conditions related to them. They are listed here in groups according to the underlying patterns that define the yaku. Example hands are given, but they are often not the only possible hand with that yaku.

All yaku can be divided into seven basic categories, depending on the dominant feature. The features are: patterns based on sequences, patterns based on triplets and/or quads, consistency of the type and numbers of the tiles, lucky draws from the wall, and special criteria.

Special criteria

Name	Japanese	Han value	Closed/Open
Ready hand	rīchi – 立直, リーチ	1	Closed only
If a player’s hand needs only one tile to win and the player has not claimed any tiles from other players to form groups, they can declare ready. To do so, the player calls out “rīchi”, discards their tile sideways, and places a 1,000-point stick on the table as a deposit. If the discard is called to win at this time, the rīchi stick is not forfeited. From this point on, they may not change the content of their hand. They must discard any tile that does not allow them to win. As an exception, they can declare a closed quad if they have a triplet and draw the fourth tile as long as it does not change the composition of the hand. For example, if a player has three 7’s of dots and they are using them as a triplet, they can make them into a quad if they draw the fourth 7. However, if two of the 7’s are being used as a pair and the third 7 is part of a sequence, declaring a quad would change the composition and would not be allowed. A round ends as a draw when all four players declare ready, and the point deposits remain on the table for the next round. A winner claims all of the table’s points in each round. Declaring ready increases the value of the hand, changes a hand containing no yaku into a valid one, and makes the chance for additional han value from the one-shot yaku and the hidden bonus tiles (Japanese: ura-dora; 裏ドラ). Another positive is that opponents may avoid trying to win altogether—they may instead concentrate on not “dealing in” to the person that declared ready even if it involves discarding potentially useful tiles. On the other hand, there are certain risks involved. First, a player who declared ready must discard all non-winning tiles, which other players may need to win. Secondly, they cannot change the hand except for making a closed quad. Third, the other players know that they are ready to go out and thus tend to be more careful about what tiles to discard. Finally, they must forfeit the 1,000-point deposit if other players win. The Japanese name of this yaku is often considered an English word reach because it is phonetically similar.

Double-ready	daburu rīchi – ダブルリーチ, or daburī – ダブリー	2	Closed only
If a player can declare ready within the first round of a hand, they can call "daburu rīchi" to declare a double-ready for two han instead of one. All other conditions are the same as declaring a normal ready.

Revealed ready hand	ōpun rīchi – オープンリーチ, or occasionally punrī – プンリー	1 + ready hands	Closed only
This is an optional rule to rīchi. A player may reveal the needed waiting tiles. In doing so, an extra han is awarded to the normal ready or double ready hand. Yakuman is awarded to winning it on a discard unless the discarder already declared ready and had no choice of discarding. Some rules say the "double revealed" ready hand has four han.

Seven pairs	chītoitsu – 七対子, or chītoi – 七対	2	Closed only

A hand composed of seven pairs is considered a valid hand in Japanese mahjong. It is one of only two hands that are an exception to the rule requiring winning hands to have four groups and one pair (the other being thirteen orphans). It also has its own special rules for scoring. The format does not count īpeikō which has three pairs (and a pair of eyes). The hand of ryanpeikō does not count seven pairs. Most Japanese play with the rule that all seven pairs must be unique. In other words, if a hand contains four red dragons, they may not be split into two pairs.

Yaku based on patterns in sequences

Name	Japanese	Han value	Closed/Open
No-points hand	pinfu – 平和	1	Closed only

This is a very common yaku, since it is rather easy to get. A no-points hand is just that—a hand that is worth no additional fu-points whatsoever. Specifically, the hand must have no triplets or quads, and must not contain any pair of dragons, player’s own wind, or wind of the round which is worth points. Furthermore, the hand must be waiting for multiple tiles to go out, such as having number 2 and 3 and waiting for 1 or 4. The reason for this is that, if the hand is in a closed, edge, or pair wait, it is worth two points, thus violating the no-points condition. Regarding combination of no-points hand and self-pick: There is a possible rule in which yaku of no-points hand and self-pick (menzenchin tsumohō) cannot be combined and instead two fu of self-drawing are awarded. In that case, no-points hand is not counted and the hand has one han with 22 fu (rounded up to 30 fu), with some other yaku available. The rule is called "pinfu–tsumo nashi" (平和自摸無し or 平和ツモなし, pinfu–tsumo invalid), sometimes contracted to "pinzumo nashi" (ピンヅモなし). If they can be combined, the rule is called "pinfu–tsumo ari" (平和自摸有り or 平和ツモあり, pinfu–tsumo valid).

One set of identical sequences	īpeikō – 一盃口	1	Closed only

One set of two sequences of the same numbers in the same suit.

Three colour straight	sanshoku doujun – 三色同順, or sanshoku – 三色	2 Closed, 1 Open	Closed/Open

Three sequences of the same numbers in all three suits.

Straight	ikkitsūkan – 一気通貫, or ittsū – 一通	2 Closed, 1 Open	Closed/Open

Three sequences of the same suit numbered 1-2-3, 4-5-6, and 7-8-9. In other words, a single-suit straight from 1 to 9.

Two sets of identical sequences	ryanpeikō – 二盃口	3	Closed only

One set of identical sequences, and another set that can match the first. Some rules may not allow the both sets to be the same (namely four identical sequences). Seven pairs yaku is not counted in this case.

Yaku based on patterns in triplets and/or quads

Any time it involves a triplet, a quad is also acceptable, though if it specifically involves quads, triplets do not count. Each yaku is worth two han, regardless of whether the hand is closed or open.

Name	Japanese	Han value	Closed/Open
All triplet hand	toitoihō – 対々和, or toitoi – 対々	2	Closed/Open

The hand consists of all triplets or quads; no sequences.

Three concealed triplets	san ankō – 三暗刻	2	Closed/Open

Three sets of triplets or quads formed without calling on any tiles. The fourth set can be an open triplet or quad, or a sequence.

Three colour triplets	sanshoku doukō – 三色同刻	2	Closed/Open

Three triplets consisting of the same numbers in all three suits.

Three quads	san kantsu – 三槓子	2	Closed/Open
Three quads in one hand. Can be open or closed. Statistically this is the rarest non-yakuman hand to occur, see the discussion in four quads.

Three chained triplets	sanrenkō – 三連刻	2	Closed/Open

A hand with three number triplets or quads in one suit with successive numbers. This hand is often optional.

Yaku based on Terminal or Honor

These yaku all have relations to terminal or honor tiles. Except for the one-han combinations or the ones specifically involving dragons or special winds, they all lose one han if the hand is open.

Name	Japanese	Han value	Closed/Open
All simples	tan'yaochū – 断么九, or tan'yao – 断么	1	Closed/Open

Tan'yaochū literally means "no 1's or 9's". Every tile in the hand is a number tile between 2 and 8 (i.e. there are no terminal or honor tiles). If this hand is open, it is called "kuitan" (喰い断), which means tan'yao made by "eating" discards. As there are varieties of rules, this hand can be closed only. The rule that does not allow kuitan is called "kuitan nashi" (喰い断無し; no kuitan, or kuitan invalid).

Honor tiles	yakuhai – 役牌, or huanpai – 飜牌	1 han per honor triplet/quad	Closed/Open

Any triplet or quad that includes either a dragon, the player’s own wind, or the prevailing wind. If a wind is both the player’s own wind and the prevailing wind, it is worth two han per group.

Terminal or honor in each set	chantaiyao – 全帯么, or chanta – チャンタ	2 Closed, 1 Open	Closed/Open

All triplets and pairs in the hand must be either 1’s or 9’s (terminals), or honor tiles (i.e., winds or dragons). For sequences, they must be either 1-2-3, or 7-8-9. This hand always contains at least one sequence.

Terminal in each set	jun chantaiyao – 純全帯么, or junchan – 純チャン	3 Closed, 2 Open	Closed/Open

The "jun" in "junchan" literally means "pure." As such, it's a pure terminal-based hand. All triplets and pairs in the hand must be either 1’s or 9’s (terminals). Sequences must be either 1-2-3 or 7-8-9. This hand contains at least one sequence, and no honors are allowed.

All terminals and honors	honrōtō – 混老頭, or honrō – 混老	2	Closed/Open
(all triplets)
(seven pairs)
This hand consists of all terminals and honors: either all triplets and quads, or seven pairs. The yaku for triplets or seven pairs are counted separately, therefore it has a minimum of 4 han.

Little three dragons	shōsangen – 小三元	2	Closed/Open

Triplets or quads of two dragons, plus a pair of the third. The yaku for "special-tiles" are counted separately, hence the hand actually has a minimum of 4 han.

Yaku based on Suit

These yaku are based on hands with only one single suit. They all lose one han if the hand is open.

Name	Japanese	Han value	Closed/Open
Half-flush	hon'īsō – 混一色, or hon'itsu – 混一	3 Closed, 2 Open	Closed/Open

The hand contains tiles from only a single suit, plus dragon or wind tiles. The honor tiles may be either the pair or a triplet.

Flush	chin'īsō – 清一色, or chin'itsu – 清一	6 Closed, 5 Open	Closed/Open

All tiles in the hand are exclusively of one suit with no honor tiles.

Yaku based on luck

These yaku all relate to draws from the wall under special, lucky circumstances. They are all worth 1 han.

Name	Japanese	Han value	Closed/Open
Self-pick	menzenchin tsumohō – 門前清自摸和, or shortly tsumo – 自摸, ツモ	1	Closed only
If a player has a concealed hand and then draws the winning tile from the wall, it adds one han to its value, even if the hand has no value. This is not applicable to open hands.

One-shot	ippatsu – 一発	1	Closed only, rīchi only
If a player declares ready (calls rīchi) and then receives the winning tile within one round of play, it adds one han to the hand’s value. The tile can either be a discard from another player or drawn from the wall. One-shot no longer applies when any other player makes a meld.

Last tile from the wall	haitei raoyue – 海底撈月, or haitei – 海底	1	Closed/Open
If the last self-drawn tile that the last player draws before reaching the dead wall completes that player's hand, the hand’s value increases by one han. Haitei raoyue means "to scoop up the reflected moon from the seabed."

Last discard	hōtei raoyui – 河底撈魚, or hōtei – 河底	1	Closed/Open
One han is added if a player wins on the last discard, that is, the tile discarded by the last player that drew the last tile from the wall. This hand is sometimes also referred to as haitei. Hōtei raoyui means "to scoop up a swimming fish from the riverbed."

Dead wall draw	rinshan kaihō – 嶺上開花, or rinshan – 嶺上	1	Closed/Open
When a player declares a quad, they must draw a supplemental tile from the dead wall to keep the number of tiles in the hand consistent. If that tile completes the hand, it adds one han to the hand’s value. Rinshan kaihō means "a flower blooms on a ridge". Sometimes the pao (包) rule is applied to this yaku, meaning that if a player uses a discard to complete a quad, then completes their hand with a tile from the dead wall, the player who discarded the tile is responsible for paying the entire amount for the hand.

Robbing a quad	chankan – 搶槓, 槍槓	1	Closed/Open
If a player has an open triplet and draws the fourth tile in the set to make a quad, they can add it to the triplet. However, if another player requires that tile to complete their hand, they can rob that tile from them. Doing so increases the hand’s value by 1 han. For example, if player A has three 6’s of dots in an open triplet, and they draw the fourth 6, they can add it to the triplet for a quad. If player B has a 4-5 of dots sequence in their hand, and that is the only set left to complete in their hand, they can then rob that fourth 6 to win. Player A then has to pay the full value of player B’s hand. Sometimes, a concealed quad can be robbed to complete the kokushi musō yakuman. For example, if player A has four west tiles and makes a quad out of them, and player B is only waiting for a west to complete their kokushi musō, they can rob the west to complete their hand. In this case, the yaku is not applied, as the kokushi musō is a yakuman.

Yaku based on the discards

One yaku is applied to the discards, as opposed to the hand value itself.

Name	Japanese	Han value	Closed/Open
Terminal/Honor discards	nagashi mangan – 流し満貫	mangan	Closed/Open
A player's discards are all terminals and honors. A round must be a draw (abortive draws not applied). The hand is often recognized only if no other player called any discard in the discard pile of the player who claims the hand. The player can make open melds depending on rules. In most cases the value is considered mangan. As for the payment, the hand is regarded as a winning by self-drawn. The rule of nō-ten bappu is usually not applied to this case not regarding the round as a draw.

Yakuman hands

There are a number of special hands that are so difficult to get that they are worth the limit in points just for having them. The limit is called yakuman (役満, or yaku-mangan 役満貫). Counts of han no longer apply to them. Likewise, the hands can be combined for multiple yakuman value. Besides, the limit of 13 han is considered as kazoe-yakuman (数え役満), or counted yakuman, which has the same value as yakuman and is achieved by a combination of some yaku, with dora tiles if a hand has them.

Some of yakuman hands may have respective names in some regions. The names used here mostly come from American publications, which are based on Chinese translations. The Thirteen orphans, Four concealed triplets and Big three dragons are the most common yakuman in Japanese mahjong and are collectively called the "Three Big Families of Yakuman" (Japanese: 役満御三家).

Name	Japanese	Value	Closed/Open
Thirteen orphans	kokushi musō – 国士無双	Limit / Double limit (13 wait)	Closed only

The Japanese name of the yaku, kokushi musō, means "a peerless distinguished person in a country." Along with seven pairs, this is the only hand that contradicts the requirement for a hand to have four sets and a pair. In a thirteen orphans hand, the player has one of each dragon tiles, one of each wind tiles, a 1 and a 9 (terminal) from each suit, plus any tile that matches anything else in the hand. If the winning tile was for your pair (namely a thirteen way wait), it is worth two yakuman (called daburu [double] yakuman). Other names for this yaku are shīsan yaochū (十三么九) which means "thirteen of smallest numbers and 9's (and honors)," or its abbreviation shīsan yao (十三么).

Four concealed triplets	sū ankō – 四暗刻	Limit / Double limit (Single wait)	Closed only

A concealed hand that consists of four triplets/quads. If the hand has two pairs left when the hand is ready, then it can only qualify as a yakuman hand if the tile is drawn off the wall. If you were in a single wait (tanki) to complete the pair for this hand, then it is worth two yakuman.

Big three dragons	daisangen – 大三元	Limit	Closed/Open

A triplet or quad of each type of dragon tile.

Little four winds	shōsūshī – 小四喜	Limit	Closed/Open

A hand consisting of three triplets/quads of winds and a pair of the fourth wind.

Big four winds	daisūshī – 大四喜	Limit/Double limit	Closed/Open

A hand consisting of four triplets/quads of winds. It can be worth one or two yakuman in some rules. Little four winds (shōsūshī) and this yaku are kinds of sūshīhō (四喜和).

All honors	tsūīsō – 字一色	Limit	Closed/Open

A hand composed exclusively of wind and dragon tiles.

Big seven stars	daichisei – 大七星	Double limit	Closed only

This is the seven pair variation to all honors. This hand adds one more yakuman towards all honors in some local rules.

All terminals	chinrōtō – 清老頭	Limit	Closed/Open

A hand consisting solely of triplets or quads of 1’s and 9’s (terminals).

All green	ryūīsō – 緑一色	Limit	Closed/Open

This hand contains only green dragons plus the 2, 3, 4, 6, or 8 of bamboo. Many of the Japanese sets exclusively color those tiles as green only. The other bamboo tiles of 1, 5, 7, and 9 have red paint on them, thereby not making them all green. Although the hand can include green dragons, it does not have to. Some Mahjong sets do not have the same color scheme.

Nine gates	chūren pōtō – 九蓮宝燈	Limit / Double limit (9 wait)	Closed only

A hand composed of 1-1-1-2-3-4-5-6-7-8-9-9-9 of one suit, plus any other tile of the same suit. Regardless of the value of the extra tile, this is always a standard mahjong hand of four sets and a pair, as shown in the animation below. Worth two yakuman if the hand was waiting on nine different tiles (or otherwise called junsei chūren pōtō [純正九蓮宝燈]), and the only possibility of that is if it had 1-1-1-2-3-4-5-6-7-8-9-9-9 and was waiting on 1, 2, 3, 4, 5, 6, 7, 8, or 9.

Four quads	sū kantsu – 四槓子	Limit	Closed/Open
Four quads in one hand. Can be open or closed. Note that in some rules, a round is a draw when four quads are made by two or more players, or when the fifth quad is made. Because of this drawing rule, and various other reasons such as the risk to open a new dora after making a quad, statistically this is the rarest yakuman to occur.

Sequential pairs of same suit simples	dai sharin – 大車輪	Limit	Closed only

A hand of seven pairs that are sequential, the same suit, and consist of only simple tiles (numbers 2 through 8). This hand is often recognized only if it is made by a suit of pinzu (筒子; circles, coins) since the Japanese name of the hand means big wheels. Some rules do not apply yakuman to the hand, in which case it has 11 han (chin'itsu, ryanpeikō, tan'yao, and pinfu). It is noted that the hand can be recognized as a pinfu hand and always has multiple waits whatever the winning tile may be. Some of its waits lose some yaku and thus decrease the value. For example, when the hand waits 7, it also waits 1 and 4. As for other suits, the hand is called bamboo forest (大竹林, dai chikurin) for bamboos and numerous neighbours (大数隣, dai sūrin) for characters.

Eight consecutive winnings	pārenchan – 八連荘	Limit	Dealer only
A player wins eight times consecutively. The conditions of the hand depend on rules. The ninth and following winnings are often yakuman again, while some rules say the sixteenth is the next yakuman. It has nothing to do with the number of honba because the number increases when a round is a draw. In some rules, no other yaku is necessary in the eighth winning. Some say the player must be a dealer from the first time. The player is always a dealer when the hand is accomplished. The hand is often optional.

Four chained triplets	sūrenkō – 四連刻	Limit	Closed/Open

A hand with four number triplets or quads in one suit with successive numbers. This hand is often optional.

Yakuman on opening hands

These are special yakuman hands, where a hand is completed on the first go-around. Thus, the yaku value is irrelevant. It is automatically a yakuman per the described criteria.

Name	Japanese	Value	Closed/Open
Heavenly hand	tenhō – 天和	Limit	Closed only, dealer only
If the 14 tiles that the dealer draws compose a complete hand, it automatically becomes a yakuman regardless of its contents. Note that, since the fourteenth tile is considered a drawn tile, coupled with the fact that it is a closed hand, the “minimum yaku requirement” is satisfied with the self-pick yaku.

Earthly hand	chīhō – 地和	Limit	Closed only, non-dealer only
If a non-dealer is dealt 13 tiles that are one tile away from a completed hand, and then draws the fourteenth tile from the wall to complete it on the first draw, it automatically becomes a yakuman hand, regardless of its contents. Because it’s a self-pick from a closed hand, it technically satisfies the “one yaku minimum” requirement.

Hand of man	renhō – 人和	Limit	Closed only, non-dealer only
If a non-dealer completes a winning hand (at least one yaku) with a discard from the first go-around, it automatically becomes a yakuman hand, regardless of its contents. Yakuman is often not applied to this hand and it can be baiman, mangan, and so on.