Riichi Mahjong Rules
There is no single "standard" riichi ruleset. Different organizations and platforms maintain their own versions. Below are the two main international tournament standards and a comparison of the most popular tournament rulesets.
World Riichi Championship rules. Developed by the WRC committee. Used at World Championships and many international tournaments. Feature a stricter approach to table etiquette rules.
Rules of the Russian riichi mahjong community. Based on EMA RCR with added akadora, abortive draws, and kazoe yakuman. Include detailed etiquette rules and are adapted to modern realities: electronic assistants, online tournaments, and streaming.
European Mahjong Association rules. Used for EMA-accredited tournaments and rankings. Latest edition — 2025, effective from January 1, 2026.
The most popular online mahjong rules (Tenhou, Mahjong Soul) and most Japanese jansou use red fives (akadora). Tournament rules typically do not include them.
Ruleset Comparison Table
| WRC | EMA RCR | Tenhou | Mahjong Soul | M-League | |
|---|---|---|---|---|---|
| Red fives (aka) | No | No | Yes (3) | Yes (3) | Yes (3) |
| Uma | 15/5/−5/−15 | 15/5/−5/−15 | 20/10/−10/−20 | 15/5/−5/−15 | 30/10/−10/−30 |
| Oka | No | No | 20 000 | No | 20 000 |
| Starting points | 30 000 | 30 000 | 25 000 | 25 000 | 25 000 |
| Kuikae (swap call) | Banned | Banned | Banned | Banned | Banned |
| Double ron | No (atamahane) | Yes | Yes | Yes | No (atamahane) |
| Triple ron | No (atamahane) | Yes | Abortive draw | Yes | No (atamahane) |
| Multiple yakuman | Yes | No | Yes | Yes | Yes |
| Kazoe yakuman (13+ han) | Yes (yonbaiman) | No (sanbaiman) | Yes | Yes | No (sanbaiman) |
| Kiriage mangan | Yes | Yes | No | No | Yes |
| Nagashi mangan | No | No | Yes | Yes | No |
| Timer | No | No | 5+10s | 5+20s | No |
This is a simplified overview. For a comprehensive comparison by Japanese pro Ooyama Neko, see: Riichi Rules Around the World — ooyamaneko.net