Japanese Mahjong: Brief Overview — Background & Rules

Riichi mahjong, more commonly known as Japanese mahjong, is a specific variant of this game. Even though the basic rules are the same, this variation has a unique ruleset which features things like dora, ura-dora, riichi, etc.


Mahjong was brought over to the Japanese Empire in 1924 by Saburo Hirayama, a Japanese soldier. He started the first mahjong club, school, and parlor in Tokyo. In the following years, the game started to noticeably increase in popularity. In the beginning, the game was simplified from the original Chinese ruleset. However, later, additional rules were introduced to increase the depth and complexity of the game.

Today, Japanese mahjong is the most beloved table game in Japan. There are approximately 7.8 million players and around 9,000 mahjong parlors in Japan. Even video arcades have mahjong arcade machines that allow you to play against others over the internet.

There are even professional mahjong players, mostly members of various organizations, which compete in numerous leagues and events with other professionals. There are around 1,000 professional mahjong players in about half a dozen organizations.

The Setup

The standard setup for Japanese mahjong requires 136 mahjong tiles. The said tiles are then shuffled and made into four walls, each 17-tiles wide, and two-stacks high. Twenty-six of these are used to build the starting hands, 35 stacks are used to form the playing wall, and the remaining seven are for a dead wall.

There are 34 types of tiles, four of each kind. Much like Chinese mahjong, there are three suits, pin, sou, and wan, and the unsuited tsu tiles. These tsu tiles are then further split between Wind and Dragon ones. Certain rulesets might contain red number five tiles, which are called dora tiles, and earn more han points. The season and flower tiles are not a part of Japanese mahjong.

General Mahjong Rules

Mahjong Rules

There are plenty of rules in Japanese mahjong that are still the same as in its Chinese counterpart.

Making Melds by Calling

One such example is making melds by calling. This means players are able to claim another player’s discarded tile. They then reveal their newly-formed meld and discard one of their tiles. However, if you claim another player’s discarded tile, this makes both the aforementioned meld as well as your hand open. Furthermore, if a winning tile of a closed hand is from the discard pile, then the meld is considered open, while the hand remains closed. All the calls function the same way as any version of mahjong. However, Japanese terminology is used in place of traditional Chinese.


If a player calls out chi, they can make an open sequential meld, which means using a tile that was discarded by the player who is sitting to their left. Melds are then placed on the table, on the right side, while the discarded tile is positioned sideways at the leftmost part of the meld.


If a player calls out pon, they can then make an open meld of the same three tiles by utilizing a tile discarded by any other players. The placement of the meld needs to be face-up.


There are three different types of quads, and kan is called out for all of them. After calling kan, the nearest dora indicator tile is turned over, and players need to draw a completely new tile from the very end of the dead wall.

  • Closed quad: Using the same four tiles, players can create a closed quad. They then reveal the meld, with two tiles face-down and two face-up. However, closed quads can’t use other players’ discard tiles. Furthermore, declaring a closed quad doesn’t make your hand open.
  • Open quad: An open quad is made by calling out kan and taking another player’s tile from the discard pile and combining it with the same three tiles from your hand. Afterwards, the player reveals the entire meld on the table.
  • Added open quad: Players can create an added open quad by calling out kan. The player then adds a self-drawn tile or a tile which is already in their hand to an open meld of the same three tiles.


Precedence Mahjong

There is a specific precedence order in who gets to pick up a discard when two or more players need the same one. Ron is first in line, then kan or pon, and lastly, chi. Kan and pon are mutually exclusive since there are only four of each type of tile.

Special Japanese Rules

Even though the basic rules of mahjong still apply in the Japanese variation, there is an additional set of special rules.

Yaku and Yakuman

Yaku are special combination of tiles or conditions that grant you the value of the hands. Unlike most variants, a winning hand needs four melds and at least one yaku. Yakus have their own han value, and the han works as a kind of doubler. Yakuman is a value for limit hands that are incredibly difficult to get, and some variants apply multiple yakuman.


If a player calls out riichi, it means he or she is declaring a ready hand, which already is a kind of yaku. A hand can be declared ready if the player only requires one tile to complete a tenpai, and the player has not collected any discard tiles to create open melds. Furthermore, when a player calls out riichi, they can win on a discarded tile even if the hand doesn’t have a yaku since riichi is in itself a yaku. However, if a player calls out riichi, they can’t change their hands anymore unless forming specific closed quads.


Dora is a special bonus tile which piles on han value to a hand. Practically any kind of tile can turn into a dora. Dora tiles add additional han value in the same amount as its corresponding “dora indicator” tiles. Furthermore, dora doesn’t count as a yaku. Therefore, it doesn’t count towards the yaku requirement which is needed for a winning hand.

At the start of a new turn, the third tile from the back of the dead wall on the upper stack is turned around and becomes a dora indicator. Each time a player hands in a quad, the next dora indicator tile in line is turned over, starting from the fourth from the back. Whenever a player declares riichi, the below the dora indicators are turned over after the win and become extra dora indicators, making them the so-called ura-dora (lit. underneath dora).

The Scoring System

In the Japanese mahjong scoring system, there are two main factors: the fu value and the aforementioned han value. Furthermore, if the han value goes over five, then the fu value, while still counted, becomes irrelevant. Winners accrue points based on these values.

Different Types of Winning

Types of Winning Mahjong

There is a difference between winning from a discard and from the wall. When about to win, players call out tsumo (self-drawn) or ron (if picking up from a discard) and not mahjong. If it’s a tsumo win, then the other three players share the burden of paying out the points. For ron, on the other hand, it’s the player who discarded the tile who pays the full number of points.

Due to this, discards are carefully arranged in Japanese mahjong. All players discard in front of themselves in neatly arranged stacks of six. This is to be able to keep track of which discards belongs to which player.

Sacred Discard

Sacred discard, or furiten, is a set of discard rules according to which a winning tile can only be taken from the wall in very specific cases:

Players can’t win on a discarded tile if the same tile is currently in the player’s own discard pile.

If a different player’s discard can create the required winning combination irrespective of yaku.

If the player has declared riichi, then the player is unable to win via a discard if the player has already discarded a winning tile.


There are various penalties for players:

  • Gotsumo: If you invalidly proclaim a winning hand
  • Furiten ron: If you claim a discard which is under the rules of furiten
  • Noten riichi: if you call riichi while having a hand that is not tenpai
  • Tahai: having more than the allowed number of tiles
  • If you crash the wall so that it can’t be reconstructed


As you can see, Riichi mahjong really is an interesting variant of the world-famous game. So if you ever get bored of the more traditional mahjong, maybe you should give this one a shot.

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