In Japanese mahjong, yaku () are patterns of tiles present in a winning hand that will award it han points. Yaku are one of two sources of han (the other being dora) for a winning hand. Unlike dora, any winning hand must satisfy at least one yaku condition. Multiple yaku may be combined to produce hands of greater value. Altogether, a hand's point value increases exponentially with every han up to the mangan limit (up to 5 han), after which more han are needed to continue increasing the hand's rank up to yakuman (13 han).
A special class of yaku exist which immediately bring a hand to the maximum rank of yakuman. These yakuman patterns do not stack with lower yaku, but may stack with other yakuman under some rules (allowing a single hand to be ranked as a multiple of yakuman). The yakuman patterns are exceedingly rare in competitive play, some to the point of obscurity.
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 the tiles. Unlike poker, however, multiple yaku may be combined to produce hands of greater value. The same applies to limit hands or yakuman, which separate from yaku and dora.
The basic concept of a yaku is that it fits into one of three basic criteria: It contains a pattern of some kind It can consistently be formed during a game, although it does not necessarily need to be common It is based on specific game situations, such as discards or actions taken by the players
Finally, when it comes to points scoring, the total number of han in the hand is counted. When the han value is 4 or less, fu is also counted. The combination of the han value and fu value corresponds to a points table.
Open and closed hands All hands start closed. A hand becomes open as soon as the player "calls" a tile discarded by an opponent, in order to complete a group from their own hand. This is called "melding." For example, if a player has in their hand, and an opponent discards a , the first player may call the discard, and thus create a melded triplet. This process can also create melded sequences (e.g. 2-3-4 of the same suit), and open quads. The calling player must display the completed group by placing the tiles face-up on the table. This makes the hand "open".
Because no open hand can become closed, certain yaku combinations either reduce its value by one if the hand is open ("Eat and decrease", a literal translation of kuisagari, 喰い下がり), or deemed impossible to complete due to the yaku requiring its hand to be closed (menzen-nomi, 門前のみ).
The only time a player can call an opponent's discard and still have their hand remain closed is when they are calling the winning tile. For scoring purposes (specifically the "Three / Four Concealed Triplets" yakus), the group with the winning called tile is considered open, but the overall hand stays closed (menzenchin 門前清 or menzen 門前).
List of yaku The following is a list of all the yaku, their names in English and Japanese, 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 often, many other arrangements are possible for each yaku. All yaku can be divided into seven basic categories, depending on the dominant feature. The features are as follows: patterns based on sequences, patterns based on triplets/quads, patterns based on terminals/honors, patterns based on suits, maximum-value hands (yakuman), lucky circumstances, and special criteria.
Special criteria Name Japanese Han value Remarks Riichi / Ready|width=40% | rīchi – , リーチ ("ready") |width=15% | 1 |width=15% | Closed hands only |- |colspan=4| When a player's hand needs only one tile to win (tenpai) while the hand is closed (i.e. the player has not called any opponent's discards to make melds), the player can opt to declare riichi. This yaku is often called "reach" because its Japanese name is phonetically similar to the English word.
Conditions after declaration To make a declaration, the player calls out “riichi”, discards their tile by placing it sideways, and places a 1,000-point stick on the table, as a deposit. From then on, any tile they draw must be automatically discarded if it does not give them a winning hand. In this way, they cannot change the content of their hand in any way (except declaring certain closed quads).
In some rulesets, a player can declare riichi only when there are four or more tiles remaining in the wall. That is, if they cannot draw another tile, they cannot declare riichi. The player is not penalized if drawing another tile is prevented due to opponents making open melds or closed quads after the declaration.
If all four players have declared riichi, a hand ends as an abortive draw. Players show their hands to confirm they are tenpai, or they are penalized with chombo.EMA's Japanese/riichi revised ruleset, effective as of March 01, 2012,
Ura dora ("underneath dora")
When a player wins, any underneath dora indicator tiles are revealed. These are just like regular dora, but the indicator lies beneath the dora tile in the dead wall. The number of ura dora tiles to be revealed is based on how many dora tiles are open via kan calls.
Riichi deposits The winner of a hand receives all 1,000-point riichi sticks that are present. In the case of multiple winners, the player closest to the discarding player (moving forward) receives all riichi deposits. If a hand ends in a draw, any riichi deposits carry over to the next game and are placed near the counters. The next winner receives those riichi deposits. In most cases, if a draw results in ending the game (such as exhaustive draws in the final round with the last dealer not ready to win, or exhaustive draws causing one or more players to reach a negative score), the game immediately ends while all riichi deposits are forfeited.
Claiming a riichi discard When a player declares riichi and discards a tile (sideways), an opponent may call that tile for a meld. The riichi player, on their next turn, places their next discard sideways. Additionally, if a riichi discard tile is called by another player to win, then the would-be riichi declaration is considered incomplete and therefore no forfeiture of riichi deposit.Wikipedia contributors, "立直," Wikipedia: Japanese-language version, August 30, 2011, 02:45 UTC.
Declaring closed quads A player declaring riichi is allowed to call a closed quad (kan). This can only happen when they have a triplet in their hand and they draw the fourth tile. Even though the hand remains closed, the quad is still displayed on the table. While in riichi, a quad call must not otherwise change the composition of the hand or its waits. For example, when a player has , they can declare a closed quad when drawing the fourth . However, when they have waiting for , or , they cannot declare a quad when drawing , because and would no longer be winning tiles. |- |colspan=4 bgcolor="#AFCDFC"| |- |width=30% | Seven Pairs|width=40% | chītoitsu – 七対子, or chītoi – 七対 |width=15% | 2 |width=15% | Closed hands only |- |colspan=4| |- |colspan=4|A hand completely composed of pairs. As the hand contains neither a four-meld-and-a-pair combination, the hand is one of the two exceptions to the rule requiring winning hands to have four groups and a pair, the other being Thirteen Orphans. This hand also has its own special rules for scoring, where it has fixed fu value of 25. Because of the scoring, Seven Pairs hand separates from Single Identical Sequences. Due to the nature of the hand being sequences, this hand is also separate from Double Identical Sequences.
In general Japanese rules, all seven pairs must be unique, meaning that the same four tiles may not be split into two pairs. Some rules, such as in the Kansai region, may accept four of the same tile, but they are not considered a quad.Wikipedia contributors, "七対子," Wikipedia: Japanese-language version, September 23, 2011, 12:27 UTC. |- |colspan=4 bgcolor="#AFCDFC"| |- |width=30% | Nagashi mangan nagashi mangan – 流し満貫 mangan Open or closedThis hand is based on discarded tiles instead. A player's discards must be all terminals (1s and 9s) and honors (dragons/winds), and the hand must end in a draw (not including abortive draws). In most rules, the yaku only applies if no opponent called a discard from the player's discard pile. Certain rules allow the player to make open melds.Wikipedia contributors, "流し満貫," Wikipedia: Japanese-language version, March 10, 2011, 11:40 UTC, retrieved June 16, 2011. In most cases, the value of this hand is mangan. When determining points, the hand is regarded as winning by self-draw. The rule of nō-ten bappu is usually not applied to this case, as it is no longer regarded as a draw. This hand cannot be combined with other hands.
The World Riichi Championship as of 2025 and the European Mahjong Association as of 2016 do not include this hand in their rulesets.
Yaku based on luck Name Japanese Han value Closed/Open Tsumo / Self-pick menzenchin tsumohō – 門前清自摸和, or shortly tsumo – 自摸, ツモ 1 Closed hand onlyWhen a player has a closed hand and draws a winning tile from the wall or the dead wall, one han is added, regardless of the hand value. Ippatsu / One-shot ippatsu – 一発 1 Requires riichi (or double riichi)After declaring ready hand, one han is added if the player wins within one go-around of play. They may win by calling an opponent's discard, or by a self-drawn tile. One-shot do not count if the go-around is interrupted by another player calling a meld, including the player declaring closed quads. Last Tile Draw / Under the Sea haitei raoyue – 海底撈月, or haitei – 海底 1 Open or Closed A player wins when they draw the very last tile (not including the dead wall). The term haitei raoyue translates as "scooping up the reflection of the moon from the bottom of the sea." Last Tile Claim / Under the River hōtei raoyui – 河底撈魚, or houtei – 河底 1 Open or Closed A player wins when they call the very last tile, discarded by an opponent. Houtei raoyui is a pun on haitei raoyue (see previous yaku explanation). It means "catching fish from the bottom of the river." Dead Wall Draw / After a Quad / After a Kan rinshan kaihō – 嶺上開花, or rinshan – 嶺上 1 Open or ClosedA player wins by drawing a supplemental tile from the dead wall, which is done after declaring a quad. Rinshan kaihō means "a flower blooms on a ridge".
Sometimes the pao (包) rule is applied to this hand. If a player claims a discard to make an open quad and then completes their hand with a tile drawn from the dead wall, the hand is considered as a discard instead of self-drawn. Robbing a Quad / Robbing a kan chankan – 搶槓, 槍槓 1 Open or ClosedA player wins when they call a tile that an opponent just used to declare a quad. Under sacred discards rule or furiten, any previously discarded tiles by that player used in that quad are not allowed to be robbed.
Robbing a closed quad
In most rulesets, a player cannot rob a closed quad, only an open one (i.e. after their opponent has "upgraded" an open triplet to a quad). Some rulesets have an exception: robbing a closed quad is allowed if it's used to complete Thirteen Orphans (in this situation, a limit would be awarded instead of the hand). Double Riichi / Double-ready daburu rīchi – ダブルリーチ, or daburii – ダブリー 2 Closed hand onlyA player declares ready on their first turn. All other conditions apply.
Yaku based on sequences Name Japanese Han value Closed/Open Pinfu / No-points hand pinfu – 平和 1 Closed hand onlyA hand that earns no fu points (which are calculated separately from han).