Yaku compatibility: Difference between revisions

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# Conflicting definitions. [[Tanyao]] requires the hand contains no honor tiles, but [[yakuhai]] requires a triplet of honor tiles, so the two cannot be combined.
# Conflicting definitions. [[Tanyao]] requires the hand contains no honor tiles, but [[yakuhai]] requires a triplet of honor tiles, so the two cannot be combined.
# When a yaku always implies another yaku, they cannot score together. For instance, a [[junchan]] hand has a terminal in every group. [[Chanta]] requires that the hand has a terminal or honor in every group. Because every junchan hand would also qualify for chanta, chanta is not scored.
# When a yaku always implies another yaku, the "lesser" yaku is not scored. For instance: [[honitsu]] requires every tile to be the same suit or an honor, while [[chinitsu]] requires every tile to be the same suit. Because every chinitsu hand counts as the cheaper honitsu, honitsu is not scored.
:There are two partial exceptions to this rule:
: There are two exceptions to this rule. [[Ippatsu]] does not imply [[riichi]] (since it could be [[double riichi]]), while [[shousangen]] doesn't imply the two dragon  [[yakuhai]] (since it doesn't guarantee any of "haku", "hatsu", and "chun").
:*[[Shousangen]] always implies two dragon yakuhai, but does not guarantee you have any one of "haku", "hatsu", or "chun".
:*[[Ippatsu]] must be scored with a hand that declares [[riichi]]. However, "riichi" and "[[double riichi]]" are considered as 2 distinct yaku. Therefore, an ippatsu hand does not guarantee "riichi", since it could also be "double riichi".


When two yaku imply each other, as with reason #2, there are two alternate ways to define it in the rules:
There are 2 alternate ways to prevent yaku from implicating each other:
*"Alter the yaku definitions so that they can never be scored together". In these rules, chanta is scored when there are honors/terminals in each group, and in addition, the hand ''must'' contain at least one honor tile.
* Alter the yaku definitions so that implied yaku are never scored together. Honitsu would be redefined as "a hand with every tile to be the same suit or an honor, including at least 1 honor".
*"Yaku that imply each other cannot be scored". In these rules, chanta is scored when there are honor/terminals in each group (not requiring an honor tile). However, chanta and junchan are never scored together. Junchan is worth more, so it supersedes chanta.
* Yaku that imply each other simply can't be scored together. Honitsu would be "a hand with every tile to be the same suit or an honor", but it cannot be scored together with chinitsu.


Both definitions are equivalent for any practical case. Most of these combinations, with the exception of toitoi + mentsumo, are based on the assumption that the yaku are defined using the second method.
These definitions are identical for any practical purpose.  
 
===Indirectly illegal===
There are a few combinations that are indirectly impossible due to the implication rule.
 
Four combinations actually form yakuman:
 
* Toitoi + Junchan = Chinroutou
* Toitoi + Mentsumo = Suuankou
* Honroutou + Junchan = Chinroutou
* Double riichi + Chankan is only possible with a Kokushi musou hand
 
Some combinations form a different yaku which implies one component of the combination, and as a result can never be counted:
 
* Toitoi + Chanta = Toitoi + Honroutou
* Chiitoitsu + Chanta = Chiitoitsu + Honroutou
* Honitsu + Tanyao = Chinitsu + Tanyao
* Honitsu + Junchan = Chinitsu + Junchan
* Chinitsu + Chanta = Chinitsu + Junchan
 
These combinations are marked with {{or}} in the table below.


== Yaku ==
== Yaku ==
{| class="wikitable" width=25%
{| class="wikitable mw-collapsible autocollapse"  
! colspan=2 | Key
|+ Key
|-
|-
!width=10%| Abbrevation !!width=90%| Yaku
!width=10%| Abbrevation !!width=90%| Yaku
Line 102: Line 80:


{{Yaku compatibility table}}
{{Yaku compatibility table}}
===Indirectly illegal===
There are a few combinations that are indirectly impossible due to the implication rule.
Four combinations actually form yakuman:
* Toitoi + Junchan = Chinroutou
* Toitoi + Mentsumo = Suuankou
* Honroutou + Junchan = Chinroutou
* Double riichi + Chankan is only possible with a Kokushi musou hand
Some combinations form a different yaku which implies one component of the combination, and as a result can never be counted:
* Toitoi + Chanta = Toitoi + Honroutou
* Chiitoitsu + Chanta = Chiitoitsu + Honroutou
* Honitsu + Tanyao = Chinitsu + Tanyao
* Honitsu + Junchan = Chinitsu + Junchan
* Chinitsu + Chanta = Chinitsu + Junchan
These combinations are marked with {{or}} in the table below.


== Yakuman ==
== Yakuman ==

Revision as of 15:21, 20 February 2025

A single hand composed of six yaku to produce a baiman hand.

This is a table showing the compatibilities of the different yaku with each other. While yaku may be combined in one hand, it is simply impossible to combine certain yaku with each other.

Overview

Yaku may not combine for two major reasons:

  1. Conflicting definitions. Tanyao requires the hand contains no honor tiles, but yakuhai requires a triplet of honor tiles, so the two cannot be combined.
  2. When a yaku always implies another yaku, the "lesser" yaku is not scored. For instance: honitsu requires every tile to be the same suit or an honor, while chinitsu requires every tile to be the same suit. Because every chinitsu hand counts as the cheaper honitsu, honitsu is not scored.
There are two exceptions to this rule. Ippatsu does not imply riichi (since it could be double riichi), while shousangen doesn't imply the two dragon yakuhai (since it doesn't guarantee any of "haku", "hatsu", and "chun").

There are 2 alternate ways to prevent yaku from implicating each other:

  • Alter the yaku definitions so that implied yaku are never scored together. Honitsu would be redefined as "a hand with every tile to be the same suit or an honor, including at least 1 honor".
  • Yaku that imply each other simply can't be scored together. Honitsu would be "a hand with every tile to be the same suit or an honor", but it cannot be scored together with chinitsu.

These definitions are identical for any practical purpose.

Yaku

Key Collapse
Abbrevation Yaku
RCH Riichi
DRI Double riichi
IPP Ippatsu
SMO Mentsumo
TAN Tanyao
PFU Pinfu
IPK Iipeikou
ITT Ittsu
YAK Yakuhai
SDJ Sanshoku doujun
SDO Sanshoku doukou
TOI Toitoi
SNA Sanankou
SNK Sankantsu
CHA Chanta
JUN Junchan
RPK Ryanpeikou
SSG Shousangen
HRO Honroutou
HON Honitsu
CHN Chinitsu
CHI Chiitoitsu
RIN Rinshan
HAI Haitei
HOU Houtei
CHK Chankan

Nagashi mangan is excluded, because it is incompatible with anything, even riichi.

Compatibility

^ Ippatsu requires riichi to be of any use.

RCH DRI IPP SMO TAN PFU IPK ITT YAK SDJ SDO TOI SNA SNK CHA JUN RPK SSG HRO HON CHN CHI RIN HAI HOU CHK
RCH
DRI
IPP
SMO
TAN
PFU
IPK
ITT
YAK
SDJ
SDO
TOI
SNA
SNK
CHA
JUN
RPK
SSG
HRO
HON
CHN
CHI
RIN
HAI
HOU
CHK

Indirectly illegal

There are a few combinations that are indirectly impossible due to the implication rule.

Four combinations actually form yakuman:

  • Toitoi + Junchan = Chinroutou
  • Toitoi + Mentsumo = Suuankou
  • Honroutou + Junchan = Chinroutou
  • Double riichi + Chankan is only possible with a Kokushi musou hand

Some combinations form a different yaku which implies one component of the combination, and as a result can never be counted:

  • Toitoi + Chanta = Toitoi + Honroutou
  • Chiitoitsu + Chanta = Chiitoitsu + Honroutou
  • Honitsu + Tanyao = Chinitsu + Tanyao
  • Honitsu + Junchan = Chinitsu + Junchan
  • Chinitsu + Chanta = Chinitsu + Junchan

These combinations are marked with in the table below.

Yakuman

Main article: Multiple yakuman

Yakuman may not combine with regular yaku. However, in certain rulesets, different yakuman can combine with each other. As a result, hands can score multiple yakuman.

The maximum number of distinct yakuman a hand can have is four: suuankou, tsuuiisou, daisuushii, and one of tenhou/chiihou/suukantsu. In rulesets where suuankou tanki and daiisuushi are scored as double, the hand ends up with a sextuple (x6) yakuman.

Compatibility

KMU DSG SUA SSS DSS TSU RYU CHR CHU SUK TEN CHH
Kokushi musou KMU
Daisangen DSG
Suuankou SUA
Shousuushii SSS
Daisuushii DSS
Tsuuiisou TSU
Ryuuiisou RYU
Chinroutou CHR
Chuuren poutou CHU
Suukantsu SUK
Tenhou TEN
Chiihou CHH

External links

Closed only Yaku - 1 han
Yaku - 1 han
Yaku - 2 han
Yaku - 3 han
Yaku - 6 han
Yakuman
Special
Optional
Topics
Hand development
Defense
Scoring
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