Ryuuiisou
Ryuuiisou 「緑一色」 is one of the standard yakuman hands. Composed of literally "all green" tiles, this yakuman is obtained when every tile in a winning hand consists only of: 2, 3, 4, 6, 8 of souzu and/or the green dragon tiles.
| Type | Yakuman |
|---|---|
| Kanji | 緑一色 |
| English | All green |
| Value | Yakuman |
| Speed | Very slow |
| Difficulty | Very hard |
Tile diagram
Winning tile: or
Open
Winning tile: or
This example is only possible under the common ruling of optional hatsu.
Value
This hand is a yakuman hand which automatically awards 32000 points to a non-dealer winner, or 48000 points to a dealer winner.
Formation
This yakuman is literally all green, as all the tiles are composed of green tiles. No markings of other color are applied to these tiles, hence its designation as all green. With this yakuman, only six tile types are available:
With the usual four melds and a pair pattern, at least five out of the six tile types are needed to complete this yakuman. Because 2-3-4 can be used in sequences, this yakuman is easier than chinroutou (which requires all triplets). Because there are only six unique tile types, this yakuman is impossible to obtain in chiitoitsu form.
Furiten
Waiting for: 
- or
This hand may regularly be subject to furiten, especially around the range of 1, 2, 3, 4, and 5 sou. While it is necessary to discard 1 sou and 5 sou to build this yakuman, these discarded tiles may lead to a tenpai hand with furiten. That may be particularly true for above example.
Variation
Some rules require hatsu (green dragon) in the hand, among them JPML A. The more common rule allows, but does not require, hatsu within the hand.
External links
- Ryuuiisou in Japanese Wikipedia
- 【麻雀】武中進の緑一色【役満】 (YouTube)
- Ryuuiisou at Nihon Pro Mahjong.