What is Kuisagari 1 Han?
Kuisagari is the rule that certain yaku lose 1 han when you call tiles (pon, chi, or open kan). The reduction is uniformly 1 han across all affected yaku, but the resulting han value splits into two groups: yaku that become exactly 1 han when open, and yaku that stay at 2 han or higher.
Yaku That Become 1 Han When Called (2 → 1)
| Yaku | Concealed | Open | Description |
|---|---|---|---|
| Sanshoku Doujun | 2 han | 1 han | Same sequence in all three suits |
| Ittsu (Ikkitsuukan) | 2 han | 1 han | 1-2-3, 4-5-6, 7-8-9 in one suit |
| Chanta (Honchantaiyao) | 2 han | 1 han | Every set contains terminal/honor |
Yaku That Drop 1 Han but Stay at 2+ Han
These also follow the kuisagari rule but remain valuable when open:
| Yaku | Concealed | Open |
|---|---|---|
| Honitsu | 3 han | 2 han |
| Junchan | 3 han | 2 han |
| Chinitsu | 6 han | 5 han |
Yaku Without Kuisagari (No Reduction)
Easy to confuse — these yaku keep their full value when called:
| Yaku | Han | Why no reduction |
|---|---|---|
| Yakuhai | 1 | Designed for calling |
| Tanyao | 1 | With kuitan rule |
| Toitoi | 2 | Built around calling |
| Sanankou | 2 | Defined by concealed triplets |
| Sankantsu | 2 | Requires kans |
| Shousangen | 2 | Yakuhai-based |
| All yakuman | 13 | Yakuman ignore kuisagari |
Why the Reduction is Exactly 1 Han
When you call tiles:
- Your hand is partially revealed to opponents
- Your tenpai speed increases significantly
The rules subtract 1 han to balance these advantages against the difficulty of staying concealed. The reduction is uniformly 1 han to keep the design symmetric.
Ankan vs Minkan
Ankan (concealed kan) is treated as concealed — kuisagari does not apply.
Sanshoku doujun + ankan → still 2 han (treated as concealed)Minkan (open kan) — both daiminkan and shouminkan — counts as calling, so kuisagari applies.
When to Call (for Yaku That Become 1 Han)
A yaku that drops to 1 han needs dora or other yaku to become a meaningful hand.
Good times to call:
- 2+ dora in hand (open sanshoku + 2 dora = 3 han)
- Combines with another yaku (open ittsu + tanyao = 2 han)
- Dealer round, prioritizing hand renchan
- Late rounds, prioritizing winning over points
Stay concealed when:
- Riichi + ippatsu + uradora potential
- No dora, no other yaku — would be just the bare yaku
- Early in the round with hand-shape options
Related Terms
- Kuisagari (general) — the broader rule
- Fuuro (Calling) — calling tiles overall
- Menzen (Concealed) — concealed hand state
- Kuitan — open tanyao rule
- Han — the unit of yaku value
Summary
Three yaku — Sanshoku Doujun, Ittsu, and Chanta — drop to 1 han when called. Honitsu, Junchan, and Chinitsu also lose 1 han but remain at 2+ han. Group these separately when memorizing to avoid confusion.
When deciding whether to call, weigh the 1-han loss against the speed boost and the dora/other-yaku you can stack on top.
