All green 緑一色 · ryuuiisou
Every tile is green: bamboo 2, 3, 4, 6, 8 and the green dragon only.
| Value | Yakuman |
|---|---|
| How often | very rare |
You rarely plan ryuuiisou from the deal. It usually reveals itself a few turns in, when a bamboo-heavy hand headed for a half flush turns out to be using only the green tiles: bamboo 2, 3, 4, 6, and 8, plus the green dragon, hatsu 發. Since 2-3-4 is the one sequence those numbers allow, every other set must be a triplet, so the hand leans on 234 runs and pons of 6s, 8s, and the dragon.
It counts open or closed, so call freely once you commit. The chase is also cheaper than it looks, because a failed attempt usually still lands as honitsu or a full flush. The classic mistake is treating every bamboo tile as green: 1, 5, 7, and 9 of bamboo all carry red in their design and disqualify the hand. One more check before you chase a version with no dragon at all — some tables require the green dragon, so confirm the table's rule first.
Key points
- The one yakuman defined by tile color rather than structure
- Whether the green dragon is required varies by ruleset — pure-bamboo versions are debated
- Said to have been popularized by American players before returning to Japan
Some rules require the green dragon; others allow all-bamboo green hands. Check the table's ruleset.
Related yaku
- Full flush 清一色 — The entire hand is one suit — the highest-value regular yaku in the game.
- All honors 字一色 — The whole hand is honor tiles — winds and dragons only.
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