|English||Small three dragons|
|Value||2 han (Consider as 4 han)|
The hand requires two out of the four tile groups to be composed of dragon triplets, while the pair is always of the third type. That leaves two tile groups to be based off of any tile composition. Often enough but not always, such a hand may be tenpai for daisangen.
Shousangen requires yakuhai, from the two groups of dragon tiles. Note that while normally a yaku is not counted if it is guaranteed by another yaku in the hand, shousangen does not guarantee a particular yakuhai and so it is counted separately. Out of the regular four tile groups for a hand, two are dedicated for dragon tiles. So, this yaku has no room for the likes of ittsu, ryanpeikou, sanshoku, and sanshoku doukou, as well as chiitoitsu because the later does not allow any mentsu. Each of those four yaku require at least three tile groups for their specific requirements. Naturally, pinfu, tanyao, junchan, and chinitsu are incompatible because of the dragon tiles.
In general, this yaku is noted as 2 han. However, it is impossible for this yaku to score without two instances of yakuhai from the two groups of sangenpai. In combination, this yaku will never produce a hand worth less than 4 han. Even with both sangenpai groups called open, that is a combination of 8 fu; and then there's 2 more fu from the sangenpai pair of the third type. The hand will almost always score at least mangan.
The lowest scoring shousangen is valued at 4 han 30 fu. The requirements to do so, assuming no additional yaku, are:
- The hand must be won by ron, as a tsumo would score 2 fu.
- The wait must be either a ryanmen or shanpon wait, as any other wait would score 2 fu.
- Both of the other groups must be shuntsu of different suits. If either was a koutsu, it would score at least 2 fu.
- Both of the yakuhai groups must be open, as they would score additional fu if closed. Note that as this is for the purposes of counting fu, if a group is completed by ron, it counts as being open.
- Neither of the yakuhai groups may be kantsu, as they would score additional fu as kantsu.
Two examples scoring exactly 4 han 30 fu on a ron:
- Shousangen in Japanese Wikipedia