World Riichi Championship Rules 2015 ～ Comments on the World Riichi Championship Rules 2015

Several yaku require the hand to be closed.
When a closed hand is won on a discard, the last group or pair is considered to be melded, but the hand is still closed.

Yaku are cumulative unless specified otherwise, so several yaku may be combined in the same hand.
Yakuman yaku are not cumulative.

For comments, I'll give visual examples.

Riichi — Riichi — [The hand must be closed]
Closed waiting hand declared at 1,000 points stake.

The player must declare riichi by clearly saying "riichi", rotating the discarded tile sideways and paying 1,000 points to the table by placing a stick by the discards.

If an opponent claims the rotated discard to win, the riichi declaration is voided and the 1,000 points are returned to the riichi declarer. If an opponent claims the rotated tile to make a group, the riichi declarer must rotate his next discard.
A player is not allowed to declare riichi if there are less than four tiles left in the wall.

A player who declared riichi can no longer change his hand. However, he may declare a concealed kong if he draws a tile matching a concealed pung, if this does not change the waiting pattern and if the three tiles can only be interpreted as a pung in the original riichi hand. (E.g. in case of three consecutive pungs in the same suit, no kong may be declared, since the tiles can be interpreted as three identical chows).

A player can declare riichi even if he's furiten.

Riichi — Riichi — [The hand must be closed]
1sou

Ippatsu — Ippatsu — [The hand must be closed]
A player who declares riichi will be rewarded for Ippatsu if he wins during the next uninterrupted set of rounds, including if he wins by self-draw on his next draw.
Calls for chow, pung or kong, including concealed kong declarations, interrupt the round, making Ippatsu invalid. Riichi declarations do not interrupt the round.

Ippatsu — Ippatsu — [The hand must be closed]

Double Riichi — Daburu riichi — [The hand must be closed]
A player who declares riichi on his first discard, during the very first un-interrupted set of turns, will be rewarded for Double Riichi.
Calls for chow, pung or kong, including concealed kong declarations, interrupt the round, making later Double Riichi invalid. Riichi declarations do not interrupt the round.

Double Riichi — Daburu riichi — [The hand must be closed]

Fully Concealed Hand — Menzen tsumo — [The hand must be closed]
Winning on a self-draw on a closed hand.

Fully Concealed Hand — Menzen tsumo — [The hand must be closed]
2sou

tsumo

Pinfu — Pinfu — [The hand must be closed]
The pinfu yaku is awarded for winning on a closed pinfu hand.
A pinfu hand is a hand worth no minipoints beside the 20 minipoints for winning and the 10 minipoints for winning on a discard on a closed hand. The 2 minipoints for winning by self-draw are omitted in order to qualify as a pinfu hand and thus to score the pinfu yaku.

Technically, a pinfu hand has four chows and a pair that is neither dragons, nor seat wind, nor prevailing wind; the winning tile completing a chow with a two-sided wait.

Pinfu — Pinfu — [The hand must be closed]
4sou

Pure Double Chow — Iipeikō — [The hand must be closed]
Closed hand with two completely identical chows, i.e. the same values in the same suit.

Pure Double Chow — Iipeikō — [The hand must be closed]
2sou

All Simples — Tan'yao
Hand with no terminals and honours. The hand can be open or closed.

All Simples — Tan'yao
3sou

Yakuhai — Yakuhai
Pung or kong of dragons, the player’s seat wind or the prevailing wind.
Multiple yakuhai combines.
If the player’s seat wind is the same as the prevailing wind, a pung or kong of this wind scores yakuhai twice.

Yakuhai — Yakuhai
3pin

(If the player is East, or if the round wind is East.)

Robbing a Kong — Chankan
Winning on a tile that an opponent adds to a melded pung in order to make a kong. Since the kong is not declared successfully, no kan dora is revealed.
Robbing a Kong is scored as a win on a discard.
Robbing a Kong also applies when winning on Thirteen Orphans on a tile used by an opponent for making a concealed kong. A concealed kong can only be robbed in the case of Thirteen Orphans.

Robbing a Kong — Chankan

After a Kong — Rinshan kaihō
Winning on a replacement tile after declaring a kong.
Counts as self-draw; the two minipoints for winning on self-draw are awarded.

After a Kong — Rinshan kaihō
2pin

rinshan

Last Tile Draw — Haitei
Winning on self-draw on the last tile of the live wall.
If the last tile of the wall is a replacement tile drawn after a kong, only After a Kong will be scored. I.e. you cannot score Last Tile Draw and After a Kong together.

Last Tile Draw — Haitei

Last Tile Claim — Hōtei
Winning by claiming the discard after the last tile of the wall.

Last Tile Claim — Hōtei

Seven Pairs — Chiitoitsu — [The hand must be closed]
Closed hand with seven different pairs. Having two identical pairs invalidates this yaku.
Seven Pairs always scores exactly 25 minipoints; extra minipoints for e.g. a pair of dragons are not awarded.

Seven Pairs — Chiitoitsu — [The hand must be closed]
5sou

Pure Straight — Ikkitsukan / Ittsū — [Worth only one han if the hand is open]
Hand with three consecutive chows in the same suit.

Pure Straight — Ikkitsukan / Ittsū — [Worth only one han if the hand is open]
1pin

Mixed Triple Chow — Sanshoku dōjun — [Worth only one han if the hand is open]
Hand with three chows of the same numerical sequence, one in each of the three suits.

Mixed Triple Chow — Sanshoku dōjun — [Worth only one han if the hand is open]
1sou

Outside Hand — Chanta — [Worth only one han if the hand is open]
All groups contain terminals or honours, and the pair is made of terminals or honours.
The hand must contain at least one chow.

Outside Hand — Chanta — [Worth only one han if the hand is open]
9sou

All Pungs — Toitoi
Hand with four pungs / kongs and a pair.

All Pungs — Toitoi
4sou

Triple Pung — Sanshoku dōkō
Hand with three pungs / kongs of the same number, one in each suit.

Triple Pung — Sanshoku dōkō
2sou

Three Concealed Pungs — San'ankō
Hand with three concealed pungs / kongs.
Note that the entire hand is not required to be closed.

Three Concealed Pungs — San'ankō
8sou

Three Kongs — Sankantsu
Hand with three kongs.

Three Kongs — Sankantsu
4pin

All Terminals and Honours — Honrōtō
Hand containing only terminals and honours.
Add two han for All Pungs or Seven Pairs.
Does not combine with Outside Hand.

All Terminals and Honours — Honrōtō
1sou

Also scores All Pungs.

1sou

Also scores Seven Pairs.

Little Three Dragons — Shōsangen
Hand with two pungs / kongs of dragons and a pair of dragons.
Add the two han for the individual pungs / kongs of dragons.

Little Three Dragons — Shōsangen
6pin

Twice Pure Double Chows — Ryanpeikō — [The hand must be closed]
Closed hand with four chows forming two distinct Pure Double Chows.
Does not combine with Pure Double Chow.

Twice Pure Double Chows — Ryanpeikō — [The hand must be closed]
5sou

Half Flush — Hon'itsu — [Worth only two han if the hand is open]
Hand with tiles from only one of the three suits, in combination with honours.

Half Flush — Hon'itsu — [Worth only two han if the hand is open]
1man

Terminals in All Groups — Junchan — [Worth only two han if the hand is open]
All groups contain terminals, and the pair is made of terminals.
The hand must contain at least one chow.
Does not combine with Outside Hand.

Terminals in All Groups — Junchan — [Worth only two han if the hand is open]
9sou

Blessing of Man — Renhō — [The hand must be closed]
Winning on a discard in the very first un-interrupted set of turns, before the player has had his first turn.
Calls for chow, pung or kong, including concealed kong declarations, interrupt the round, making later Blessing of Man invalid. Riichi declarations do not interrupt the round.
Blessing of Man is not cumulative with other yaku and dora.

Blessing of Man — Renhō — [The hand must be closed]
Blessing of Man is only scored mangan, while Blessing of Heaven and Blessing of Earth are yakuman hands, because my survey of competition rules around the world shows that Blessing of Heaven and Blessing of Earth are widely used and scored yakuman, while Blessing of Man is a mixed case: some score it yakuman, others give mangan, and other others give nothing.
On this point, WRCR is kinda mid-path world's custom.

For info, at the time of WRCR's first version, RMU used to score Blessing of Man 4 han cumulative with other yaku and dora, but recently (2014) switched it to nothing.

Full Flush — Chin'itsu — [Worth only five han if the hand is open]
Hand composed entirely of tiles from only one of the three suits, without any honours.
Does not combine with Half Flush.

Full Flush — Chin'itsu — [Worth only five han if the hand is open]
2pin

Blessing of Heaven — Tenhō — [The hand must be closed]
East player winning on his initial dealt tiles.
Not valid if the player declares a concealed kong.

Blessing of Heaven — Tenhō — [The hand must be closed]

Blessing of Earth — Chihō — [The hand must be closed]
Winning on self-draw in the very first un-interrupted set of turns.
Calls for chow, pung or kong, including concealed kong declarations, interrupt the round, making later Blessing of Earth invalid. Riichi declarations do not interrupt the round.

Blessing of Earth — Chihō — [The hand must be closed]

Thirteen Orphans — Kokushi musō — [The hand must be closed]
Closed hand with one of each of the thirteen different terminal and honour tiles, plus one extra terminal or honour tile. The hand can be completed on any tile; it does not need to be waiting on thirteen different tiles.

As a special case, it's possible to rob a concealed kong to win on Thirteen Orphans.

Thirteen Orphans — Kokushi musō — [The hand must be closed]
It does not need to be waiting on thirteen different tiles.
1sou

Nine Gates — Chūren pōto — [The hand must be closed]
Closed hand consisting of the tiles 1112345678999 in the same suit, plus any one extra tile in the same suit. The hand can be completed on any tile; it does not need to be waiting on nine different tiles.

Nine Gates — Chūren pōto — [The hand must be closed]
1man

Four Concealed Pungs — Sūankō
Hand having four concealed pungs and/or kongs.
I.e. a closed hand with four concealed pungs, completed by self-draw or by claiming a tile to complete the pair.

Four Concealed Pungs — Sūankō
1pin

tsumo

Four Kongs — Sūkantsu
Hand with four kongs.

Four Kongs — Sūkantsu
5sou

All Green — Ryūiisō
Hand composed entirely of green tiles. Green tiles are: Green dragon and 2, 3, 4, 6 and 8 of bamboo. The hand is not required to include the Green dragon.

All Green — Ryūiisō
The hand is not required to include the Green dragon.
2sou

All Terminals — Chinrōtō
Hand composed entirely of terminal tiles.

All Terminals — Chinrōtō
1man

All Honours — Tsūiisō
Hand composed entirely of honour tiles.

All Honours — Tsūiisō
south

Big Three Dragons — Daisangen
Hand with three pungs and/or kongs of dragons.
A player feeding the last pung or kong may be subject to liability payment.

Big Three Dragons — Daisangen
1pin

Little Four Winds — Shōsūshi
Hand with three pungs and/or kongs of winds and a pair of winds.

Little Four Winds — Shōsūshi
7man

Big Four Winds — Daisūshi
Hand with four pungs and/or kongs of winds.
A player feeding the last pung or kong may be subject to liability payment.

Big Four Winds — Daisūshi
2sou

While it makes sense to score Big Four Winds more than Little Four Winds, EMA and Mahjong Montréal (now Club Riichi de Montréal) are the world exceptions about it. According to my survey, every other competition rules score both Little Four Winds and Big Four Winds single yakuman.
Also, allowing a double yakuman while not allowing to stack two yakuman makes a clumsy scoring system.

Ooyamaneko.net

6.5Yaku list

6.5Yaku list

6.5.1One han yaku

6.5.1One han yaku

6.5.2Two han yaku

6.5.2Two han yaku

6.5.3Three han yaku

6.5.3Three han yaku

6.5.4Mangan yaku

6.5.4Mangan yaku

6.5.5Six han yaku

6.5.5Six han yaku

6.5.6Yakuman yaku

6.5.6Yakuman yaku

6.5Yaku list Several yaku require the hand to be closed. When a closed hand is won on a discard, the last group or pair is considered to be melded, but the hand is still closed. Yaku are cumulative unless specified otherwise, so several yaku may be combined in the same hand. Yakuman yaku are not cumulative.	6.5Yaku list For comments, I'll give visual examples.
6.5.1One han yaku	6.5.1One han yaku
Riichi — Riichi — [The hand must be closed] Closed waiting hand declared at 1,000 points stake. The player must declare riichi by clearly saying "riichi", rotating the discarded tile sideways and paying 1,000 points to the table by placing a stick by the discards. If an opponent claims the rotated discard to win, the riichi declaration is voided and the 1,000 points are returned to the riichi declarer. If an opponent claims the rotated tile to make a group, the riichi declarer must rotate his next discard. A player is not allowed to declare riichi if there are less than four tiles left in the wall. A player who declared riichi can no longer change his hand. However, he may declare a concealed kong if he draws a tile matching a concealed pung, if this does not change the waiting pattern and if the three tiles can only be interpreted as a pung in the original riichi hand. (E.g. in case of three consecutive pungs in the same suit, no kong may be declared, since the tiles can be interpreted as three identical chows). A player can declare riichi even if he's furiten.	Riichi — Riichi — [The hand must be closed]
Ippatsu — Ippatsu — [The hand must be closed] A player who declares riichi will be rewarded for Ippatsu if he wins during the next uninterrupted set of rounds, including if he wins by self-draw on his next draw. Calls for chow, pung or kong, including concealed kong declarations, interrupt the round, making Ippatsu invalid. Riichi declarations do not interrupt the round.	Ippatsu — Ippatsu — [The hand must be closed]
Double Riichi — Daburu riichi — [The hand must be closed] A player who declares riichi on his first discard, during the very first un-interrupted set of turns, will be rewarded for Double Riichi. Calls for chow, pung or kong, including concealed kong declarations, interrupt the round, making later Double Riichi invalid. Riichi declarations do not interrupt the round.	Double Riichi — Daburu riichi — [The hand must be closed]
Fully Concealed Hand — Menzen tsumo — [The hand must be closed] Winning on a self-draw on a closed hand.	Fully Concealed Hand — Menzen tsumo — [The hand must be closed] tsumo
Pinfu — Pinfu — [The hand must be closed] The pinfu yaku is awarded for winning on a closed pinfu hand. A pinfu hand is a hand worth no minipoints beside the 20 minipoints for winning and the 10 minipoints for winning on a discard on a closed hand. The 2 minipoints for winning by self-draw are omitted in order to qualify as a pinfu hand and thus to score the pinfu yaku. Technically, a pinfu hand has four chows and a pair that is neither dragons, nor seat wind, nor prevailing wind; the winning tile completing a chow with a two-sided wait.	Pinfu — Pinfu — [The hand must be closed]
Pure Double Chow — Iipeikō — [The hand must be closed] Closed hand with two completely identical chows, i.e. the same values in the same suit.	Pure Double Chow — Iipeikō — [The hand must be closed]
All Simples — Tan'yao Hand with no terminals and honours. The hand can be open or closed.	All Simples — Tan'yao
Yakuhai — Yakuhai Pung or kong of dragons, the player’s seat wind or the prevailing wind. Multiple yakuhai combines. If the player’s seat wind is the same as the prevailing wind, a pung or kong of this wind scores yakuhai twice.	Yakuhai — Yakuhai (If the player is East, or if the round wind is East.)
Robbing a Kong — Chankan Winning on a tile that an opponent adds to a melded pung in order to make a kong. Since the kong is not declared successfully, no kan dora is revealed. Robbing a Kong is scored as a win on a discard. Robbing a Kong also applies when winning on Thirteen Orphans on a tile used by an opponent for making a concealed kong. A concealed kong can only be robbed in the case of Thirteen Orphans.	Robbing a Kong — Chankan
After a Kong — Rinshan kaihō Winning on a replacement tile after declaring a kong. Counts as self-draw; the two minipoints for winning on self-draw are awarded.	After a Kong — Rinshan kaihō rinshan
Last Tile Draw — Haitei Winning on self-draw on the last tile of the live wall. If the last tile of the wall is a replacement tile drawn after a kong, only After a Kong will be scored. I.e. you cannot score Last Tile Draw and After a Kong together.	Last Tile Draw — Haitei
Last Tile Claim — Hōtei Winning by claiming the discard after the last tile of the wall.	Last Tile Claim — Hōtei
6.5.2Two han yaku	6.5.2Two han yaku
Seven Pairs — Chiitoitsu — [The hand must be closed] Closed hand with seven different pairs. Having two identical pairs invalidates this yaku. Seven Pairs always scores exactly 25 minipoints; extra minipoints for e.g. a pair of dragons are not awarded.	Seven Pairs — Chiitoitsu — [The hand must be closed]
Pure Straight — Ikkitsukan / Ittsū — [Worth only one han if the hand is open] Hand with three consecutive chows in the same suit.	Pure Straight — Ikkitsukan / Ittsū — [Worth only one han if the hand is open]
Mixed Triple Chow — Sanshoku dōjun — [Worth only one han if the hand is open] Hand with three chows of the same numerical sequence, one in each of the three suits.	Mixed Triple Chow — Sanshoku dōjun — [Worth only one han if the hand is open]
Outside Hand — Chanta — [Worth only one han if the hand is open] All groups contain terminals or honours, and the pair is made of terminals or honours. The hand must contain at least one chow.	Outside Hand — Chanta — [Worth only one han if the hand is open]
All Pungs — Toitoi Hand with four pungs / kongs and a pair.	All Pungs — Toitoi
Triple Pung — Sanshoku dōkō Hand with three pungs / kongs of the same number, one in each suit.	Triple Pung — Sanshoku dōkō
Three Concealed Pungs — San'ankō Hand with three concealed pungs / kongs. Note that the entire hand is not required to be closed.	Three Concealed Pungs — San'ankō
Three Kongs — Sankantsu Hand with three kongs.	Three Kongs — Sankantsu
All Terminals and Honours — Honrōtō Hand containing only terminals and honours. Add two han for All Pungs or Seven Pairs. Does not combine with Outside Hand.	All Terminals and Honours — Honrōtō Also scores All Pungs. Also scores Seven Pairs.
Little Three Dragons — Shōsangen Hand with two pungs / kongs of dragons and a pair of dragons. Add the two han for the individual pungs / kongs of dragons.	Little Three Dragons — Shōsangen
6.5.3Three han yaku	6.5.3Three han yaku
Twice Pure Double Chows — Ryanpeikō — [The hand must be closed] Closed hand with four chows forming two distinct Pure Double Chows. Does not combine with Pure Double Chow.	Twice Pure Double Chows — Ryanpeikō — [The hand must be closed]
Half Flush — Hon'itsu — [Worth only two han if the hand is open] Hand with tiles from only one of the three suits, in combination with honours.	Half Flush — Hon'itsu — [Worth only two han if the hand is open]
Terminals in All Groups — Junchan — [Worth only two han if the hand is open] All groups contain terminals, and the pair is made of terminals. The hand must contain at least one chow. Does not combine with Outside Hand.	Terminals in All Groups — Junchan — [Worth only two han if the hand is open]
6.5.4Mangan yaku	6.5.4Mangan yaku
Blessing of Man — Renhō — [The hand must be closed] Winning on a discard in the very first un-interrupted set of turns, before the player has had his first turn. Calls for chow, pung or kong, including concealed kong declarations, interrupt the round, making later Blessing of Man invalid. Riichi declarations do not interrupt the round. Blessing of Man is not cumulative with other yaku and dora.	Blessing of Man — Renhō — [The hand must be closed] Blessing of Man is only scored mangan, while Blessing of Heaven and Blessing of Earth are yakuman hands, because my survey of competition rules around the world shows that Blessing of Heaven and Blessing of Earth are widely used and scored yakuman, while Blessing of Man is a mixed case: some score it yakuman, others give mangan, and other others give nothing. On this point, WRCR is kinda mid-path world's custom. For info, at the time of WRCR's first version, RMU used to score Blessing of Man 4 han cumulative with other yaku and dora, but recently (2014) switched it to nothing.
6.5.5Six han yaku	6.5.5Six han yaku
Full Flush — Chin'itsu — [Worth only five han if the hand is open] Hand composed entirely of tiles from only one of the three suits, without any honours. Does not combine with Half Flush.	Full Flush — Chin'itsu — [Worth only five han if the hand is open]
6.5.6Yakuman yaku	6.5.6Yakuman yaku
Blessing of Heaven — Tenhō — [The hand must be closed] East player winning on his initial dealt tiles. Not valid if the player declares a concealed kong.	Blessing of Heaven — Tenhō — [The hand must be closed]
Blessing of Earth — Chihō — [The hand must be closed] Winning on self-draw in the very first un-interrupted set of turns. Calls for chow, pung or kong, including concealed kong declarations, interrupt the round, making later Blessing of Earth invalid. Riichi declarations do not interrupt the round.	Blessing of Earth — Chihō — [The hand must be closed]
Thirteen Orphans — Kokushi musō — [The hand must be closed] Closed hand with one of each of the thirteen different terminal and honour tiles, plus one extra terminal or honour tile. The hand can be completed on any tile; it does not need to be waiting on thirteen different tiles. As a special case, it's possible to rob a concealed kong to win on Thirteen Orphans.	Thirteen Orphans — Kokushi musō — [The hand must be closed] It does not need to be waiting on thirteen different tiles.
Nine Gates — Chūren pōto — [The hand must be closed] Closed hand consisting of the tiles 1112345678999 in the same suit, plus any one extra tile in the same suit. The hand can be completed on any tile; it does not need to be waiting on nine different tiles.	Nine Gates — Chūren pōto — [The hand must be closed]
Four Concealed Pungs — Sūankō Hand having four concealed pungs and/or kongs. I.e. a closed hand with four concealed pungs, completed by self-draw or by claiming a tile to complete the pair.	Four Concealed Pungs — Sūankō tsumo
Four Kongs — Sūkantsu Hand with four kongs.	Four Kongs — Sūkantsu
All Green — Ryūiisō Hand composed entirely of green tiles. Green tiles are: Green dragon and 2, 3, 4, 6 and 8 of bamboo. The hand is not required to include the Green dragon.	All Green — Ryūiisō The hand is not required to include the Green dragon.
All Terminals — Chinrōtō Hand composed entirely of terminal tiles.	All Terminals — Chinrōtō
All Honours — Tsūiisō Hand composed entirely of honour tiles.	All Honours — Tsūiisō
Big Three Dragons — Daisangen Hand with three pungs and/or kongs of dragons. A player feeding the last pung or kong may be subject to liability payment.	Big Three Dragons — Daisangen
Little Four Winds — Shōsūshi Hand with three pungs and/or kongs of winds and a pair of winds.	Little Four Winds — Shōsūshi
Big Four Winds — Daisūshi Hand with four pungs and/or kongs of winds. A player feeding the last pung or kong may be subject to liability payment.	Big Four Winds — Daisūshi While it makes sense to score Big Four Winds more than Little Four Winds, EMA and Mahjong Montréal (now Club Riichi de Montréal) are the world exceptions about it. According to my survey, every other competition rules score both Little Four Winds and Big Four Winds single yakuman. Also, allowing a double yakuman while not allowing to stack two yakuman makes a clumsy scoring system.