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Beginner's Lesson 26

Optional Rules

In this lesson, we will cover a few common optional rules in riichi mahjong.


The first and most prominent rule is the inclusion of “aka dora”. This literally translates to “red dora”, and refers to special dora tiles that are completely red. Generally, when aka dora are included, a 5 from each suit will be replaced with an aka dora. These red 5pin, red 5sou, and red 5man are treated as extra dora tiles. Other than that, they do not differ from their normal counterparts. Additionally, if a 5 would happen to be a normal dora, the corresponding red 5 counts as 2 dora by itself. With aka dora, hand values tend to be much higher, and it is easier to make expensive open hands as well.


The second optional rule is called “kuikae”. This is translated to “swap calling”, and refers to whether or not you are allowed to use calls to swap equivalent tiles. If kuikae is disallowed, then you would not be allowed to discard the other side of a “ryanmen chi”. As an example, if you declare chi on a 4man using a 56man ryanmen from your hand, you would not be allowed to discard 7man from your hand.


Kuikae is mainly allowed in rulesets that remove ippatsu, ura dora, kan dora, and aka dora; these rulesets are only used in some professional mahjong organizations in Japan, so it is usually safe to assume that kuikae is disallowed. Breaking this rule usually results in a dead hand. Also, be aware that in any competitive rulesets, discarding the tile you just called is also against the rules. This is true even in rulesets where kuikae is allowed.


The last optional rule we will cover is called “atamahane”. This is translated to “head bump” and refers to the number of players that can win from another player’s discard. If atamahane is enabled, only 1 player can win their hand. The player who wins is the one whose turn would come first, going around the table in the usual turn order. For example, if the player who is south discards a tile that both the north and east players can win from, only the north player will win their hand. This is because from the discarding player’s perspective, the north player’s turn comes before the east player’s turn. Competitive rulesets use atamahane more commonly than not.


Conversely, if atamahane is not used, then “multiple ron” is allowed. As you might expect, that means that multiple players can win from a single discard, and the discarding player is responsible for paying all of them. In these cases, if one of the players who won is east, then they get renchan as normal. Any extra payments from the honba and riichi sticks on the table usually go to 1 of the winning players, and how this would work is usually follows the same concept as atamahane.


And with that, you have finished all of the lessons in this beginner’s section! You should now have a firm grasp of the basic rules of riichi mahjong. We hope that you enjoy playing this game that we all love.


However, if you want to become a stronger player, feel free to move onto our intermediate section. In it, we will discuss what it means to be an intermediate-level player, the skills necessary to improve at mahjong, and the expected mindset of a competitive player.

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