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Ruleset authorities
'''Rule variations''' are adjustments to the game's rules. Due to the wide variety of organizations that offer mahjong, there are many variations.


WoRR – Word Riichi Rules for the tourney in France, 2014. This ruleset is still in development. Not all details have been decided yet.
<div style="float:right; margin:0 0 1em 1em;">__TOC__</div>
Ema2 – European Mahjong Association (EMA) Riichi Competition Rules (RCR) from 2012
JpmlA – Japan Professional Mahjong League (JPML) ruleset A
JpmlB – Japan Professional Mahjong League (JPML) ruleset B
NPM – Nihon Pro Mahjong (NPM)
Skoui – Saikouisen, the oldest Japanese professional league
SkouC – Saikouisen Classic
MuMa – Mu Mahjong
RmuA – Real Mahjong Unit (RMU) ruleset A
RmuB – Real Mahjong Unit (RMU) ruleset B
RmuC – Real Mahjong Unit (RMU) ruleset C
101 – Ruleset of 101, another Japanese league
Tenho – Tenhou.net, a popluar internet game site
Skyos – Saikyousen, a tournament in Japan run by Takeshobo
Korea – Korean Mahjong League (KML)
Uspml – United States Professional Mahjong League (USPML)
Montr – Mahjong Montreal, Canada
Kuitan


Allow the 1-han yaku tanyao (all simples) to be awarded to an open hand.
== Overview ==
While the standard rules of Japanese mahjong are already complex, they are furthered complicated by the amount of variations. There is no one governing body for mahjong rules, so it is natural for many variations to exist. Many "fringe" variations, such as [[shuugi]] and [[yakitori]], are almost exclusively used in gambling settings.


ari – Allowed
Most optional rules have two settings: "ari" (on) or "nashi" (off). For example, [[#Atozuke|Atozuke ari]] means you are allowed win under the state of [[atozuke]], while atozuke nashi means you aren't allowed to win.
nashi – Not allowed
option – Tenhou.net offers both rules in different games. You can play kuitan nashi only if you play akadora nashi, see below. The Korean rules write "[concealed hand only selective]", which sounds as if kuitan were an optional rule.
Atodzuke


Allow the hand to win even if there exists no yaku that is satisfied with all wait tiles. Atodzuke nashi, also called sakidzuke ari, requires all winning possibilities to satisfy at least one same yaku. Sakidzuke requires some
== Agari ==
A set of variations dictate how hands produce winning hands.


ari – Atodzuke: Allow determination of yaku after determining the winning tile.
=== Agariyame ===
nashi – Sakidzuke: Require a fixed yaku no matter how the hand wins.
{{main|Agariyame}}
Kuikae


Allow a player to call pon or chii on a tile, then afterwards discard the same tile, or a tile which would have completed the two revealed tiles at the other end of the sequence (switching chii).
Allow the dealer to end the hanchan prematurely, while in possession of the lead in the round [[Oorasu|South 4]] or in the [[West round]] after one hand has been played.


full – Allow to discard any tile.
* Lead – Allow the dealer to end the hanchan prematurely, with the last dealer is in the lead.
swap – Forbid discarding the same tile, allow switching chii.
* End – The dealer may end the game after one hand in the final round, regardless of point standing.
nashi – Forbid discarding the same tile, forbid switching chii.
* Nashi – The game must continue until the seat winds rotate again.
Start score


Each player has this many points at the start of a hanchan.
=== Atozuke ===
{{main|Atozuke}}


0 – Start at zero points, but allow players to go into the negatives without consequences
Atozuke handles the rule for yakuless hands to gain yaku on discards.  This is most common on hands waiting on more than two tiles, where one discarded tile produces yakuhai.
25k–30k – Reaching a negative score aborts the hanchan.
Goal score


Used at the end of a hanchan for the next two rules: If oka is used, first place gets a bonus payment, called the oka, of 3 × (goal − start score), paid evenly by the others. If shaaba is used, the game continues into the west round if no player has reached the goal score after the south round.
* Ari – Allow the hand to gain yaku on the winning tile.
* Nashi – Yaku must be embedded in the hand before the winning tile.
* ? - A hand must have a yaku confirmed by the time the first call completes (exception: "whole hand yaku", e.g. [[honitsu]], can be incomplete on first call).


goal > start – Oka may be paid, shaaba may used; see those rules.
=== Double ron ===
goal = start – Oka is zero, shaaba is never used.
Score two winning declarations at the same time.
Tobi (bankrupt)
 
End the hanchan prematurely if a player has less than 0 points at the end of a hand.
 
Oka
 
Jackpot for getting first. All three other players pay one third of this to first place after the end of the hanchan. These points are exchanged in addition to the uma.
 
Uma
 
This is a placing bonus for first and second place after a hanchan. First place receives (larger amount × 1,000) points from forth place, and second place receives (lower amount × 1,000) from third place. These points are exchanged in addition to the oka.
 
0 – No placement bonus is exchanged.
share – Ask Sylvain what this means in detail. I don't know. :-)
X/Y – First place receives (X × 1,000) points from fourth place, second place receives (Y × 1,000) points from third place.
Shaaba
 
If nobody has reached the goal score at the end of south 4th hand, then the game continues into the west round. The game immediately stops after any hand during the west round in which a player reaches the goal score. The game never continues into the north round.
 
ari – Continue into west round.
nashi – Always stop after south 4th hand.
Akadora


Use some red fives in place of normal fives as extra dora.
* Ari – Discarder of the winning tile must pay both hands separately. Riichi sticks are collected by the first winner to the right. Some rules entitle the other winner to one of these riichi sticks if he has declared riichi during this hand.
* Check – Like ari, but the fourth player must reveal a non-winning hand, so that a [[triple ron]] can be avoided.
* Close – [[Atamahane]], or head bump. Only the first win closest to the discarder is recognized.
* Far – Applying the head bump rule in reverse, where the player farther from the discarder overrides the closer player.


ari – Use three red fives, one per suit.
=== Furiten riichi ===
nashi – Don't use any red fives.
{{main|Furiten}}
option – Tenhou.net offers both rules in different games. You can play akadora ari only if you if you play kuitan ari.
Uradora


Winning riichi declarers may flip the tile underneath the first dora indicator and treat that as another dora indicator.
Allow players to declare riichi while they are furiten due to their own earlier discards.


ari – Flip the first ura dora indicator.
* Ari – Allowed
nashi – Don't flip it. Riichi declarers will know in advance how much their hand is worth.
* Nashi – Disallowed
Kandora


After declaring a kantsu, another dora indicator is flipped in the dead wall. All four players can benefit from this.
=== Last turn riichi ===
{{main|Riichi}}


ari – Flip a new kan dora indicator after declaring a kantsu, but I don't know the exact timing rules.
Allow players to declare riichi after their last draw in the current round (i.e. more than 0, but less than 4 tiles in the live wall).
sokun. – Sokunori: After declaring any type of kantsu, flip the next dora indicator immediately.
late – After declaring ankan (concealed kantsu), flip the next dora indicator immediately. After declaring a minkan (open kantsu per call on a discard or per extension of a minkou), flip the next dora indicator only after declaring tsumo, declaring another kan, or discarding. The new dora indicator is in effect for any type of win.
nashi – Don't flip any dora indicators upon declaring kantsu.
Kanuradora


Winning riichi declarers may flip the tile underneath each kan dora indicator and treat that as another dora indicator.
* Ari – Allowed. In this case ippatsu can combine with houtei. Declaring riichi after drawing the last tile in the wall is never allowed.
* Nashi – Disallowed


Ryanhan shibari
=== Ryanhan shibari ===
{{main|Ryanhan shibari}}


Impose a two-han minimum at five or more honba (number of table counters). The two han must both come from yaku.
Impose a two-han minimum at five or more honba (number of table counters). The two han must both come from yaku.


ari – Require two han from yaku at five or more honba.
* Ari – Require two han from yaku at five or more honba.
nashi – One han from yaku is always enough.
* Nashi – One han from yaku is always enough.
Renchan
 
agari – The hand is repeated only when East wins.
tenpai – The hand is repeated when East wins, or when East is tenpai upon exhaustive draw.
nanba – The hand is repeated when East wins, or when East is tenpai upon exhaustive draw, or when there is any exhaustive draw during the nanba (south round).
option – The rules allow two possible options, agari and tenpai.
Agari yame
 
Allow the dealer to end the hanchan prematurely if he wins the south 4th hand and ends up in first place, or if that hand becomes an exhaustive draw and the dealer ends up first.
 
ari – Allow the dealer to end the hanchan prematurely.
nashi – The game must continue until the seat winds rotate again.
Abortive draw
 
Abort a hand and repeat it at the next honba (number of table counters) in case of nine terminals and honors, same wind discards, four riichi declarations, or four kantsu declarations. Some rules abort the hand upon a triple ron; that is not covered by this rule, instead see triple ron.
 
ari – Abort and reshuffle in these situations.
nashi – Do not recognize any of these abortive criteria. Play every hand until a winning declaration or exhaustive draw. Do not allow a fifth kan declaration nonetheless.
Yakitori
 
Have players who do not win a hand during the entire hanchan pay a penalty to those who do, or to whoever is first. This is not used in any listed ruleset.
 
Double ron
 
Score two winning declarations at the same time.
 
ari – Discarder of the winning tile must pay both hands separately. Riichi sticks are collected by the first winner to his right. Some rules entitle the other winner to one of these riichi sticks if he has declared riichi during this hand.
check – Like ari, but the fourth player must reveal a non-winning hand, so that he cannot intentionally avoid the triple ron abortive draw.
nashi – Atama hane: head bump, recognize only the first win to the discarder's right.
Triple ron


=== Triple ron ===
Score three winning declarations at the same time.
Score three winning declarations at the same time.


ari – Discarder of the winning tile must pay all three hands separately. See double ron ari for distribution of riichi sticks.
* Ari – The discarder of the winning tile must pay all three hands separately. See double ron ari for distribution of riichi sticks.
ata.h. – Atama hane: head bumb, recognize only the first win to the discarder's right.
* Atama – [[Atamahane]], or head bump. Only the first win to the discarder's right is recognized.
abort – Do not score any hand, instead abort the hand with an abortive draw (tochuu ryuukyoku).
* Abort – No hands are scored, and instead, the hand is [[abortive draw|aborted]].
Furiten riichi


Allow players to declare riichi while they are fuiten due to their own earlier discards.
== Chombo ==
{{main|Chombo}}
Variations on chombo may involve its general usage.  Common and casual games may not even enforce chombo due to the setting.  On the other hand, high profile settings may require stricter enforcement and harsher point penalties.


Temp. furiten
=== Enforcement ===
Point deductions may be applied immediately after the incident, the hand, or factored after the game to avoid time delay during the game.


If a non-riichi player ignores a winning tile, he becomes temporarily furiten. There are different rules to when this status wears off.
* Immediate – Chombo applied immediately.
* Hand – Deduction after the hand.
* Game – Deduction at the end of the game with raw points.
* Uma – Deduction applied after the calculation of the end game score.
* Null – Chombo disregarded.


turn – The player's next own discard ends temporary furiten. If his turn is skipped due to other players' pon calls, he remains temporarily furiten.
=== Points ===
call – The players next own discard ends temporary furiten, but also any player's call of chii, pon, or kan, even for a concealed kantsu, ends temporary furiten.
Point variation on the penalty points may be applied.
Call precedence


If several players call chii, pon, or ron on the same tile, this rule decides who will get the tile. Kan calls are treated like pon calls.
* Standard – The penalized must pay the equivalent to a mangan tsumo.
* Mod – Modified amounts to the point penalty may be specified.


pon – Like pon above, but keep in mind that this is a computer game (C), not a ruleset for live play.
=== Toppling tiles ===
time – Pon trumps chii if called at the same time, otherwise the first call stands. Ron trumps anything, even if called slightly later.
A penalty may be applied to toppling tiles of off the dead wall.
Kiriage mangan


Score 4 han, 30 fu as a mangan, as well as 3 han, 60 fu. The exact values for these hands are 7,700 points on a non-dealer ron, split as 2,000 and 3,900 on a non-dealer tsumo, and 11,600 points on a dealer ron, split as 3,900 for all on a dealer tsumo.
* Ld6c – If at least one tile from the dead wall is toppled, then the hand is declared dead. If six or more are toppled, then chombo is applied.
* Comp – This is a computer game. The rules infraction cannot occur.


ari – Round up to mangan, i.e., score 8,000 or 12,000 points.
=== Wall toppling ===
nashi – Score the exact values.
A penalty may be applied to toppling tiles of off the live wall.
Leftover riibo


If the last hand of the hanchan is a draw, there may be leftover riichi sticks on the table. This rule decides what happens with them.
* 6c – If six or more are toppled, then chombo is applied..
* Comp – This is a computer game. The rules infraction cannot occur.


lost – Nobody gets the leftover riichi sticks.
== Dora ==
share – The players with the highest scores share the sticks equally. There is no information on how fractional sticks are handled for 3 or 4 tying players.
{{main|Dora|Dora variations}}
tiebr. – The table winner gets the sticks. If several players tie for first place, better places are assigned according to initial winds.
back – The sticks go back to the players who bet them.
Scorekeeping


Keep track of player's scores during a hanchan.
Variations on [[dora]] involves a few implementations; and they all affect the number of dora used.  The most common variation involves the '''akadora''' (red five) regarding its inclusion or exclusion.  Other variations places options on the kandora and even the uradora.  Lesser variations may include additional '''dorahyouji''' (dora indicators) at the beginning of each hand.


option – Each tournament can specify a suitable scorekeeping method.
== Furiten ==
paper – Scores are written down on a scoresheet.
{{main|Furiten}}
tenbo – Scoring sticks (tenbo) are exchanged after each hand.
comp. – This is a computer game and it keeps track of scores automatically.
Ippatsu


Score an additional han for winning a riichi declaration within the next go-around.
If a non-riichi player ignores a winning tile, then temporary furiten is applied. Different rules apply as to when this status wears off.


ari – Score ippatsu as an extra 1-han yaku.
* Turn – The player's next own discard ends temporary furiten. If the turn is skipped due to other players' pon calls, temporarily furiten is retained.
nashi – Don't score ippatsu.
* Call – The players next own discard ends temporary furiten, but also any player's call of [[Naki|chii, pon, or kan]], even for a concealed [[Kan|kantsu]], ends temporary furiten.
Daburu riichi


Score riichi as 2 han yaku instead of 1 han if called within the first uninterrupted go-around of a hand.
== Kuikae ==
{{main|Kuikae}}


ari – Score daburu riichi as 2 han instead of 1 han.
This allows a player to call pon or chii on a tile, then afterwards discard the same tile, or a tile which would have completed the two revealed tiles at the other end of the sequence (switching chii).
nashi – Always score 1 han per riichi declaration.
Open riichi


Allow players to declare open riichi instead of a normal riichi. Open riichi is worth 2 han instead of the normal 1 han. The declarer must reveal his hand at the same time as he pays the bet of 1,000 points.
* Full – Allow to discard any tile.
* Swap – Forbid discarding the same tile, allow switching chii.
* Nashi – Forbid discarding the same tile, forbid switching chii.


ari – Allow open riichi along with normal riichi.
== Kuitan ==
nashi – Don't allow open riichi.
{{main|Kuitan}}
Nagashi mangan


Score a mangan upon exhaustive draw for having discarding only yaochuuhai during the entire hand, with none of the yaochuuhai having been called by other players, and without having called any tiles oneself. If this is allowed, there are additional rules decisions necessary: Does it count as a win, or merely as replacement of the noten penalty? Are concealed kantsu allowed?
Allow the 1-han yaku tanyao (all simples) to be awarded to an open hand.


ari – Score nagashi mangan, but I don't know the details.
* Ari – Allowed
ari B – Score nagashi mangan as a replacement of the noten penalty, not as a fully-fledged win. I don't know what happens if you declare ankan, that will likely prevent nagashi mangan.
* Nashi – Not allowed
ari KW – Score nagashi mangan as a win (W), voiding noten riichi chombos and collecting riichi bets and honba payments. It is legal to declare a concealed kantsu (K) and still score nagashi mangan.
* Option – Tenhou.net offers both rules in different settings.  One of the game rooms is set for both kuitan nashi and akadora nashi. However, there is no setting for one or the other exclusively. The Korean rules write "concealed hand only selective", which sounds as if kuitan were an optional rule.
nashi – Don't allow nagashi mangan.
Haitei/houtei


Score the 1-han yaku haitei raoyue for winning with the last tile from the live wall, or score the 1-han yaku houtei raoyui for winning on a discard while the live wall is empty.
== Naki ==
{{main|Naki}}


ari – Both yaku are allowed.
Variation may apply on tile calls.  If several players call chii, pon, or ron on the same tile, this rule decides who will get the tile. Kan calls are treated like pon calls.
nashi – Neither yaku is allowed.
Haitei rinshan


When a kantsu is declared with exactly one tile left in the live wall, that tile, called the haiteihai, is appended to the dead wall and never drawn. This rule makes the replacement tile the haiteihai, so winning with that tile scores both rinshan kaihou (winning after kan) and haitei raoyui (winning with the last tile).
* Pon – Like pon above, but keep in mind that this is a computer game (C), not a ruleset for live play.
* Time – Pon trumps chii if called at the same time, otherwise the first call stands. Ron trumps anything, even if called slightly later.


ari – Allow this combination. I consider this a bug in the 2012 EMA RCR.
== Scoring ==
nashi – Do not allow this combination. This is Japanese default.
{{main|Scoring variations}}
Tenhou/chihou


Score a self-drawn win within a hand's first uninterrupted go-around as a yakuman.
Scoring allows some flexibility to the rules regarding the start and end scores.  Likewise, the oka and uma may be adjusted as well.


ari – Score tenhou and chihou as yakuman.
== Tochuu ryuukyoku ==
nashi – Score these wins as normal hands.
{{main|Tochuu ryuukyoku}}
Renhou


This is a yaku for winning on a discard before the winner's first turn in an uninterrupted go-around.
Abort a hand and repeat it at the next honba (number of table counters) in case of nine terminals and honors, same wind discards, four riichi declarations, or four kantsu declarations. Some rules abort the hand upon a triple ron; that is not covered by this rule, instead see triple ron.


yak. – Yakuman: Score this as a yakuman. No other yaku is necessary.
* Ari – Abort and reshuffle in these situations.
mang. – Mangan: Score this as a mangan. No other yaku is necessary. The hand can be either won with renhou, or with its normal yaku and dora. Winning with the latter is only possible if the hand has at least one han through other yaku and the han from yaku and dora total 6 or more.
* Nashi – Do not recognize any of these abortive criteria. Play every hand until a winning declaration or exhaustive draw. Do not allow a fifth kan declaration nonetheless.
4 han – Renhou is a 4-han yaku that combines with all others. Winning with only renhou is valid and worth mangan.
nashi – Renhou is not a yaku. The hand is scored normally, there must be at least one other yaku present for a valid win.
Daisharin


ari – Score this hand as a yakuman.
== Yaku ==
nashi – Score this hand normally. With the guaranteed yaku chinitsu, ryanpeiko, and pinfu, is worth at least 11 han.
{{main|Yaku variations}}
Paarenchan


Score the eighth consecutive win of the same dealer as a yakuman.
Different yaku may be subject to rule variation.  Some are simply not considered standard.


Kazoe yakuman
== External links ==
 
* [https://ooyamaneko.net/en/mahjong/rratw/index.php Riichi rules around the world] - Chart of riichi rule variations between various platforms.
Score a hand with 13 han or more as a yakuman.
 
ari – Score as a yakuman with 8,000 basic points.
nashi – Score as a sanbaiman with 6,000 basic points.
Double yakuman
 
Score each of the listed patterns as a double yakuman.
 
nashi – All yakuman count as single yakuman. See combined yakuman below for another possibility to score a multiple yakuman.
D – Daisuushii : Big four winds, four groups of winds.
S – Suuankou tanki : Four concealed triplets winning from the single pair wait.
K – Kokushi musou shiisanmen machi : Thirteen orphans winning from the thirteen-sided wait on the pair.
9 – Junsei chuuren pooto : Nine heavenly gates winning from the nine-sided wait 1112345678999.
Comb. yakuman
 
Score more than one yakuman if multiple yakuman are achieved by the same hand.
 
ari – Add one yakuman per single yakuman, add two yakuman per double yakuman if allowed, and score the sum.
nashi – Score only one yakuman per hand, or two yakuman if double yakuman are allowed.
DaiSG/DaiSS pao
 
Impose a liability payment on the player who has dealt the third ponned dragon tile, or the fourth ponned wind tile, if the caller wins with daisangen (big three dragons) or daisuushii (big four winds) later.
 
ari – Liable player pays full on tsumo, half on ron.
nashi – No liability for daisangen or daisuushii.
Suukantsu pao
 
Impose a liability payment on the player who has dealt the fourth kanned tile, if the caller wins with suukantsu (four kantsu) later.
 
ari – Liable player pays full on tsumo, half on ron.
nashi – No liability for suukantsu.
Daiminkan pao
 
After forming a daiminkan (kan declaration on a discard with three concealed identical tiles), score a win with rinshan kaihou (winning on the replacement tile after a kan call) as a ron against the discarder of the called tile.
 
ari – Score the hand as a ron if won before the next discard.
nashi – Score the hand as a tsumo.
Rinshan fu
 
Award a hand winning with the rinshanpai (kan replacement tile) the usual 2 fu for winning with a self-drawn tile.
 
2 fu – Award the hand 2 fu for tsumo.
nashi – Don't count any fu for tsumo on the rinshanpai.
Double wind pair


A hand with four groups and a pair might have a double wind pair, i.e., a pair of winds that are both the round wind and the seat wind. This rule decides how many fu such a double wind pair is worth.
[[Category:Rule variations]]
 
Wall toppling
 
What is the penalty for toppling tiles from the live wall?
 
6c – If you topple six tiles or more, you get a chombo.
comp. – This is a computer game. The rules infraction cannot occur.
Dead w. toppling
 
What is the penalty for toppling tiles from the dead wall?
 
1d6c – If you topple at least one tile from the dead wall, you get a dead hand. If you topple six or more, you get a chombo.
comp. – This is a computer game. The rules infraction cannot occur.
 
== External links ==
[http://asdfasdf.ethz.ch/~simon/riichi/committee/worldrules.php Source page]

Latest revision as of 18:11, 12 October 2024

Rule variations are adjustments to the game's rules. Due to the wide variety of organizations that offer mahjong, there are many variations.

Overview

While the standard rules of Japanese mahjong are already complex, they are furthered complicated by the amount of variations. There is no one governing body for mahjong rules, so it is natural for many variations to exist. Many "fringe" variations, such as shuugi and yakitori, are almost exclusively used in gambling settings.

Most optional rules have two settings: "ari" (on) or "nashi" (off). For example, Atozuke ari means you are allowed win under the state of atozuke, while atozuke nashi means you aren't allowed to win.

Agari

A set of variations dictate how hands produce winning hands.

Agariyame

Main article: Agariyame

Allow the dealer to end the hanchan prematurely, while in possession of the lead in the round South 4 or in the West round after one hand has been played.

  • Lead – Allow the dealer to end the hanchan prematurely, with the last dealer is in the lead.
  • End – The dealer may end the game after one hand in the final round, regardless of point standing.
  • Nashi – The game must continue until the seat winds rotate again.

Atozuke

Main article: Atozuke

Atozuke handles the rule for yakuless hands to gain yaku on discards. This is most common on hands waiting on more than two tiles, where one discarded tile produces yakuhai.

  • Ari – Allow the hand to gain yaku on the winning tile.
  • Nashi – Yaku must be embedded in the hand before the winning tile.
  • ? - A hand must have a yaku confirmed by the time the first call completes (exception: "whole hand yaku", e.g. honitsu, can be incomplete on first call).

Double ron

Score two winning declarations at the same time.

  • Ari – Discarder of the winning tile must pay both hands separately. Riichi sticks are collected by the first winner to the right. Some rules entitle the other winner to one of these riichi sticks if he has declared riichi during this hand.
  • Check – Like ari, but the fourth player must reveal a non-winning hand, so that a triple ron can be avoided.
  • Close – Atamahane, or head bump. Only the first win closest to the discarder is recognized.
  • Far – Applying the head bump rule in reverse, where the player farther from the discarder overrides the closer player.

Furiten riichi

Main article: Furiten

Allow players to declare riichi while they are furiten due to their own earlier discards.

  • Ari – Allowed
  • Nashi – Disallowed

Last turn riichi

Main article: Riichi

Allow players to declare riichi after their last draw in the current round (i.e. more than 0, but less than 4 tiles in the live wall).

  • Ari – Allowed. In this case ippatsu can combine with houtei. Declaring riichi after drawing the last tile in the wall is never allowed.
  • Nashi – Disallowed

Ryanhan shibari

Main article: Ryanhan shibari

Impose a two-han minimum at five or more honba (number of table counters). The two han must both come from yaku.

  • Ari – Require two han from yaku at five or more honba.
  • Nashi – One han from yaku is always enough.

Triple ron

Score three winning declarations at the same time.

  • Ari – The discarder of the winning tile must pay all three hands separately. See double ron ari for distribution of riichi sticks.
  • Atama – Atamahane, or head bump. Only the first win to the discarder's right is recognized.
  • Abort – No hands are scored, and instead, the hand is aborted.

Chombo

Main article: Chombo

Variations on chombo may involve its general usage. Common and casual games may not even enforce chombo due to the setting. On the other hand, high profile settings may require stricter enforcement and harsher point penalties.

Enforcement

Point deductions may be applied immediately after the incident, the hand, or factored after the game to avoid time delay during the game.

  • Immediate – Chombo applied immediately.
  • Hand – Deduction after the hand.
  • Game – Deduction at the end of the game with raw points.
  • Uma – Deduction applied after the calculation of the end game score.
  • Null – Chombo disregarded.

Points

Point variation on the penalty points may be applied.

  • Standard – The penalized must pay the equivalent to a mangan tsumo.
  • Mod – Modified amounts to the point penalty may be specified.

Toppling tiles

A penalty may be applied to toppling tiles of off the dead wall.

  • Ld6c – If at least one tile from the dead wall is toppled, then the hand is declared dead. If six or more are toppled, then chombo is applied.
  • Comp – This is a computer game. The rules infraction cannot occur.

Wall toppling

A penalty may be applied to toppling tiles of off the live wall.

  • 6c – If six or more are toppled, then chombo is applied..
  • Comp – This is a computer game. The rules infraction cannot occur.

Dora

Main articles: Dora and Dora variations

Variations on dora involves a few implementations; and they all affect the number of dora used. The most common variation involves the akadora (red five) regarding its inclusion or exclusion. Other variations places options on the kandora and even the uradora. Lesser variations may include additional dorahyouji (dora indicators) at the beginning of each hand.

Furiten

Main article: Furiten

If a non-riichi player ignores a winning tile, then temporary furiten is applied. Different rules apply as to when this status wears off.

  • Turn – The player's next own discard ends temporary furiten. If the turn is skipped due to other players' pon calls, temporarily furiten is retained.
  • Call – The players next own discard ends temporary furiten, but also any player's call of chii, pon, or kan, even for a concealed kantsu, ends temporary furiten.

Kuikae

Main article: Kuikae

This allows a player to call pon or chii on a tile, then afterwards discard the same tile, or a tile which would have completed the two revealed tiles at the other end of the sequence (switching chii).

  • Full – Allow to discard any tile.
  • Swap – Forbid discarding the same tile, allow switching chii.
  • Nashi – Forbid discarding the same tile, forbid switching chii.

Kuitan

Main article: Kuitan

Allow the 1-han yaku tanyao (all simples) to be awarded to an open hand.

  • Ari – Allowed
  • Nashi – Not allowed
  • Option – Tenhou.net offers both rules in different settings. One of the game rooms is set for both kuitan nashi and akadora nashi. However, there is no setting for one or the other exclusively. The Korean rules write "concealed hand only selective", which sounds as if kuitan were an optional rule.

Naki

Main article: Naki

Variation may apply on tile calls. If several players call chii, pon, or ron on the same tile, this rule decides who will get the tile. Kan calls are treated like pon calls.

  • Pon – Like pon above, but keep in mind that this is a computer game (C), not a ruleset for live play.
  • Time – Pon trumps chii if called at the same time, otherwise the first call stands. Ron trumps anything, even if called slightly later.

Scoring

Main article: Scoring variations

Scoring allows some flexibility to the rules regarding the start and end scores. Likewise, the oka and uma may be adjusted as well.

Tochuu ryuukyoku

Main article: Tochuu ryuukyoku

Abort a hand and repeat it at the next honba (number of table counters) in case of nine terminals and honors, same wind discards, four riichi declarations, or four kantsu declarations. Some rules abort the hand upon a triple ron; that is not covered by this rule, instead see triple ron.

  • Ari – Abort and reshuffle in these situations.
  • Nashi – Do not recognize any of these abortive criteria. Play every hand until a winning declaration or exhaustive draw. Do not allow a fifth kan declaration nonetheless.

Yaku

Main article: Yaku variations

Different yaku may be subject to rule variation. Some are simply not considered standard.

External links

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