Curriculum · 15 / 50
Triplet yaku: toitoi, sanankou, and shousangen
Learn the five yaku built from triplets and quads, including the decisive rule for a triplet completed by ron.
The principle
Toitoi is worth 2 han for four triplets or quads and a pair, whether open or closed. Sanankou is also worth 2 han, but requires three genuinely concealed triplets or quads.
Rule and example
A triplet completed by ron is considered open. A hand with two concealed triplets that wins by ron on a shanpon wait therefore does not score sanankou. Ron that only completes the pair leaves the existing triplets concealed.
What changes
Sanshoku doukou combines the same numbered triplet in all three suits. Sankantsu requires three quads. Each is worth 2 han, whether the groups are open or concealed.
Mistake to avoid
Shousangen combines two dragon groups with a pair of the third dragon. It is worth 2 han, plus the two yakuhai produced by those dragon groups, for at least 4 han before other bonuses.
Rules references
- Tenhou rulesReference profile used for game mechanics and scoring.
- WRC Rules 2025International rules compared whenever their options differ from Tenhou.