Yaku

Yaku (役) are specific hand patterns or conditions needed in order to score a hand. In a sense, they are synonymous to "poker hands". Yet, unlike poker hands, yaku are worth specific "han values"; and various yaku may be combined together into one hand. basic mahjong knowledge involves learning the yaku, but it is not expected of new players to know them.

Han

Main article: Scoring

Each yaku is assigned han values. Most have static values, regardless of the hand being closed or open. However, some decrease in han value while being open. Furthermore, some also require hands to remain closed in order to count. For hands to maximize the total han value, different yaku may be combined into a single hand.

The list

Main article: List of yaku

This is a quick, short list of the standard yaku. A number of optional yaku exist as well.

Yaku

Menzen tsumo 「門前清自摸和」

This yaku may apply to any closed hand. Any player who draws a winning tile with a closed hand is awarded this yaku.

Riichi 「立直」

This is a special yaku applied to closed tenpai hands, which requires the player to make a declaration and "wager".

Ippatsu 「一発」

This is applied when the player calling riichi wins within 4 tile draws/discards. In addition, the cycle must not be interrupted by tile calls.

Pinfu 「平和」

Typically known as "all sequences", this is a hand that does not gain fu based on composition, other than that of a closed ron.

Iipeikou 「一盃口」

This hand includes two identical sequences.

Haitei raoyue 「海底撈月」

The hand is completed with the last tile on the wall.

Houtei raoyui 「河底撈魚」

The hand is completed with the very last discarded tile.

Rinshan kaihou 「嶺上開花」

This yaku is awarded upon winning with a tile from the dead wall.

Chankan 「搶槓」

The winning tile for a hand is called on another player's Kan. Essentially, the tile needed to complete a Kan is stolen to complete a winning hand.

Tanyao 「断幺九」

A hand composed of only inside (numbers 2-8) tiles

Yakuhai 「役牌」

A hand with at least one group of dragon tiles, seat wind, or round wind tiles. This hand can be valued at 1 han for each group.

Double riichi 「ダブルリーチ」

Riichi is declared with a dealt hand before the first discard.

Chanta 「全帯幺九」

All melds contain at least 1 terminals or honor.

Sanshoku 「三色同順」

Three sequences have the same number across the three different suits.

Ittsu 「一通貫」

This hand has a complete sequence of 1 through 9 of a single suit. As a note, the sequence of 1-9 are actually three groups of sequences numbered 123, 456, and 789.

Toitoi 「対々」

The entire hand is composed of triplets.

Sanankou 「三暗刻」

The hand includes three sets of triplets that have been formed without calling any tiles. The fourth set can be an open triplet or sequence.

Sanshoku doukou 「三色同刻」

The hand includes three groups of triplets with the same number.

Sankantsu 「三槓子」

Three kans are called for this hand.

Chiitoitsu 「七対子」

This hand is composed of seven pairs. It is one of two exceptions to the standard 4 melds and a pair pattern.

Honroutou 「混老頭」

The hand is composed of nothing but all terminals and honors. † This hand may be considered as 4 han, because it is impossible to score this hand without either chii toitsu or toi toi.

Shousangen 「小三元」

The hand contains two sets of 3 dragon tiles and a pair of the third dragon tiles. † This hand may be considered as 4 han, because it is impossible to score this hand without two sets of yakuhai, from the two sets of dragons.

Honitsu 「混一色」

This is a single suit hand mixed with some honor tiles.

Junchan 「純全帯么」

All sets contain at least one terminal.

Ryanpeikou 「二盃口」

This hand has two sets of "iipeikou". This hand does not combine with chii toitsu, even though the hand can be interpreted as one.

Chinitsu 「清一色」

This hand is composed entirely of tiles from only one of the three suits. It is the only yaku set at 6 han, where the number drops to 5 han when opened.

Nagashi mangan 「流し満貫」

All the discards are terminals and/or honors. In addition, none of these discards were called by other players.

Yakuman

Main article: Yakuman

This is a specific set of "yaku", known as yakuman.

Romaji	Kanji	Han value	Explanation Kazoe yakuman 「数え役満」 This is a special class of yakuman, where a hand is composed of 13+ han based on the combination of above regular yaku and/or dora. Kokushi musou 「国士無双 国士無双１３面待ち」 This hand has one of each of the 13 different terminal and honor tiles plus one extra terminal or honour tile. Some rules may allow double yakuman for a 13-wait set. Suuankou 「四暗刻 四暗刻単騎」 This hand is composed of four sets of closed triplets. When this hand has a shanpon pattern and the win is via ron, then it would not be counted as suu ankou. Daisangen 「大三元」 This has possesses three groups of all the dragons. Shousuushi 「小四喜」 This hand has three groups of the wind tiles plus a pair of the fourth kind. Daisuushi 「大四喜」 This hand has four groups of all four wind tiles. Tsuuiisou 「字一色」 Every group of tiles are composed of honor tiles. Chinroutou 「清老頭」 Every group of tiles are composed of terminal tiles. Ryuuiisou 「緑一色」 A hand composed entirely of green tiles: 2, 3, 4, 6 and 8 Sou and/or Hatsu. Chuuren poutou 「九連宝燈 純正九蓮宝燈」 A hand consisting of the tiles 1112345678999 in the same suit plus any one extra tile of the same suit. Suukantsu 「四槓子」 This hand with four Kan's. Tenhou 「天和」 The dealer hand is a winning hand even before discarding a tile. Chiihou 「地和」 The non-dealer hand is a winning hand after the first draw.

External links

• Yaku frequency among Tenhou.net players (Japanese)

Lists all the yaku occurrences in Tenhou.net by percentages and by room

• Yaku short list

Pointing out which yaku to learn first