, also known as , is a variant of mahjong. Japanese mahjong shares the same basic rules as other mahjong variants, but also features a unique set of rules such as (a wager that one's hand will win without being altered further) and the use of (randomly selected tiles that will score bonus points). The variant is one of a few styles where discarded tiles are ordered rather than placed in a disorganized pile. This is primarily due to the rule, which takes player discards into account. The variant has grown in popularity due to anime, manga, and online platforms.

History In 1909, Nagawa Higosaku brought a Mahjong set to Japan for the first time (or at least there seems to be no earlier record of Mahjong tiles in Japan).. In Japan, the game was first simplified; then, later, additional rules were added to increase the complexity. Mahjong, as of 2010, is the most popular table game in Japan.Pakarnian, John, "Game Boy: Glossary of Japanese Gambling Games", Metropolis, January 22, 2010, p. 15. As of 2008, there were approximately 7.6 million mahjong players and about 8,900 mahjong parlors in the country, and it was estimated that parlors made over 300 billion yen in sales that year.Matsutani, Minoru, "Mah-jongg ancient, progressive", Japan Times, June 15, 2010, p. 3. There are several manga and anime devoted to dramatic and comic situations involving mahjong (see Media),Schodt, Frederik, Manga! Manga! The World of Japanese Comics. Kodansha, 1986, Chapter 5 as well as video games.

In Japan, there are what are known as professional players, usually members of organizations that compete in internal leagues and external events with other professionals and the general public. There are over 2,400 professionals spread across a half-dozen organizations. There is no universal authority for riichi mahjong in Japan: professionals cannot dictate how mahjong parlors or amateur organizations and players operate. There are therefore many small differences in the rules, and each mahjong parlor and league defines their own rules. Likewise, there is no global authority regulating riichi mahjong. Since 2018, there exists a league of select professionals (coming from the other professional mahjong organizations) run by Abema named M.League which presents mahjong as a professional sport. Teams of professionals receive salary as players, compete in ranking and playoffs as teams, and wear team jerseys to enhance the image of mahjong as a sport.

Tiles

Japanese mahjong is usually played with 136 tiles. The tiles are mixed and then arranged into four walls that are each two stacked tiles high and 17 tiles wide. 26 of the stacks are used to build the players' starting hands, 7 stacks are used to form a dead wall, and the remaining 35 stacks form the live wall from which tiles are drawn.

There are 34 different kinds of tiles, with four of each kind. Just like standard mahjong, there are three suits of tiles, (circles), (bamboo) and (characters), and unranked . Honor tiles are further divided between wind tiles and dragon tiles. Some rules may have red number five tiles which work as that earn more value. The flower and season tiles are omitted. Names for suit tiles follow the pattern of [number] + [suit], the numbers being Japanese interpretations of the corresponding Chinese words.

Collectively, the circle, bamboo and character tiles are referred to as . Among them, the 1s and 9s are called , while the rest (2s through 8s) are the . Together, the honor and terminal tiles make up the .

Named as each tile consists of a number of circles.

Named as each tile consists of a number of bamboo sticks (also interpreted as strings) that hold a hundred coins each. The face of the number one tiles is a peafowl.

Named as each tile consists of a number of ten thousands (, , or ; see the lower character on the tile). Originally, this was 10,000 coins made up of 100 strings of 100 coins each (see mahjong tiles). The kanji of number five usually becomes instead of . The modern Japanese standard uses as the suit's suffix, most western languages including English will use instead to avoid confusion with "one". The seven in this suit would thus be called in Japanese, but seven-man (or 7-man) in English.

Named after the four cardinal directions. (East) (South) (West) (North)

, , and . Often, the face of the White dragon tiles is blank white. The kanji of the Green dragon tiles in Japan is usually which is slightly different from since it includes instead of .

General mahjong rules

Many basic rules of mahjong apply to the Japanese variation. Valid collections of three tiles are called groups (), divided into triplets () and sequences (). Players can also form a quad () using four of the same tile.

Making groups by calling (melding) Players can make a meld (open group) by calling for another player's discard. They reveal the meld on the table and then make their own discard. Calling for another player's discard makes the group and the hand open. When a winning tile of a closed hand is a discard, the group including that discard is also considered open, while the hand is still regarded as closed. The calls operate exactly the same as any variation of mahjong, except Japanese terminology is used.

Players can make an open sequential group, a sequence (three consecutive tiles in the same suit), by calling out "" ( or ) using a tile discarded by the player to their left. Players place the meld face up on the table, usually on the right side of their hands, with the discard placed sideways at the leftmost position of the meld to indicate which tile was taken from the left player's discard pile.

Players can make an open identical group, a triplet (three identical tiles in the same suit or honor tiles) by calling out "" ( or ) using a tile discarded by any other player. Players place the meld face up on the table with one of those tiles placed sideways to indicate from whom the discard was taken.

Players can make a meld from four identical tiles in the same suit or four identical honor tiles. After calling a quad, the next adjacent indicator tile is flipped, and players need to draw a supplemental tile from the end of the dead wall. Depending on the rules, the number of tiles in the dead wall is kept at 14 by reserving the last available tile from the wall, or the number decreases at that time. There are three types of quads. Players call out "" ( or ) for all of them.

Closed quad (Ankan or 暗槓): Players can make a closed quad if they have four of the same tile in their hand. They reveal those tiles, then place them to the right side of their hand with two tiles face up and two face down. They then draw another tile from the dead wall. A closed quad does not use another player's discard and does not open their hand. Open quad (Daiminkan or 大明槓): Players can make an open quad using another player's discarded tile if they have three of that same tile in their hand. They reveal the meld on the table with all four tiles face up, with one placed sideways to indicate from whom the discard was taken. Players cannot make this type of quad using an open meld of three tiles. Added open quad: Players can make an (or by adding a self-drawn tile or a tile already in their hand to an open meld of the same three tiles.Wikipedia contributors, "槓," Wikipedia: Japanese-language version, February 24, 2011, 00:40 UTC, retrieved February 24, 2011. The tile is usually added sideways on top of the sideways tile in the open meld.

Precedence order The order of precedence to pick up a discard when two or more players want it is (winning via a discard tile) first, or second, and third. and cannot happen at the same time since there are only four of each tile. Depending on the ruleset being used, these calls may be allowed when the next player has already drawn and seen their next tile. In such cases, that player takes first precedence if they call (winning via self-drawing a tile).

Japanese rules overview While the basic rules to mahjong apply with the Japanese variation, an additional, distinct set of rules are applied.

and

Hand types, or , are specific combinations of tiles or conditions that yield the value of hands. Unlike many variants, a winning hand must have at least one . When scoring, each has its own value, with every approximately doubling the value of a hand up to a limit.

A is a rare with stringent criteria which automatically scores the maximum number of points, ignoring any other scoring patterns. In some variations, multiple can be scored at the same time.

Declaring means declaring a ready hand, and is a kind of . A player may declare a ready hand if their hand needs only one tile to complete a legal hand (), and the player has not claimed another players' discards to make open melds. When declaring , the player must place their 1,000-point stick and place their discarded tile sideways; the hand is then fixed and may not be changed except when forming certain closed quads. After declaring a ready hand, a player can win on any drawn or discarded tile even if their hand has no other .

As a possible house rule, a player can choose to reveal their hand when declaring to win more points if successful, which is called . In that case, the player shows only the tiles that are related to waits, or reveals all the tiles in the hand depending on the rules.Wikipedia contributors, "立直," Wikipedia: Japanese-language version, March 10, 2011, 05:16 UTC, retrieved July 23, 2011. The declaration increases the count allowing the player to score extra points.

Dora are bonus tiles that add value to a winning hand. Every kind of tile can become a bonus tile, allowing its value to increment based on the amount of its corresponding "indicator" tiles. Bonus tiles are not counted as , regardless of the number of tiles present; the player still must form a in order to count.Wikipedia contributors, "ドラ (麻雀)," Wikipedia: Japanese-language version, August 31, 2011, 01:16 UTC.

At the start of a hand, the upper tile from the third stack from the back end of the dead wall is flipped and becomes a bonus tile indicator. A tile of a next succeeding number or color is the bonus tile. For example, if an indicator is a Green dragon (), Red dragons () are counted as a bonus tile by the sequence shown below, in which the Red dragon wraps around to the White dragon ().

The succeeding order of bonus tile is as follows:

→→→→→→→→→

→→→→→→→→→

→→→→→→→→→

→→→→

→→→

The number of bonus tile indicators increases in the following manner: each time a player calls a quad, the next adjacent bonus indicator tile is flipped, starting with the upper tile from the fourth stack from the back end. The indicator is flipped immediately after the quad is called, and after that the player draws a supplemental tile for their hand from the back end of the dead wall. The number of indicators increases in that direction, which becomes five if a single player calls four quads, and that is the largest possible number from the upper tiles in the third to seventh stacks of the dead wall (see four quads).

Additional bonus points can be awarded in the following situations:

: when a player wins with a ready hand declaration, the tiles underneath the bonus tile indicators become additional bonus tile indicators as well. : a variation uses specially marked red number 5 tiles that are also bonus tiles, regardless of whether it is indicated or not. The red 5 tiles also stack with normal bonus tiles if the indicator tile displays a 4. One red 5 tile for each suit is usually used in place of regular five tiles, with some local variants using various amounts (two 5-pin only, two 5-pin and one 5-sō and 5-wan, two of each 5 in all three suits, et cetera). In some variations, tiles of other numbers such as 3 or 7 can be marked red.

Scoring system