Key takeaways
- Japanese Mahjong, or Riichi Mahjong, uses 136 basic tiles without traditional flower tiles.
- A standard win has four melds and one pair, but it must also contain at least one yaku.
- A closed player at tenpai may declare riichi; riichi is a yaku and restricts later hand changes.
- Dora adds han but is not a yaku. A dora-only completed hand cannot win.
- Furiten prevents a discard win while still allowing self-draw, making it central to both attack and defense.
What is Japanese Riichi Mahjong?
Japanese Riichi Mahjong is a 13-tile form built around riichi, yaku, dora, furiten, and fu-han scoring. Four players compete for points, and a decision depends not only on winning a hand but also on dealer status, round wind, placement, and the number of hands remaining.
Professional groups, competitions, and online platforms still use different details. This introduction uses the World Riichi Championship 2025 rules as a verifiable competition reference. Red fives, open tanyao, abortive draws, bankruptcy, and placement bonuses should still be checked at the actual table.
Which tiles are used?
Riichi uses 136 tiles—four copies of 34 types:
| Group | Contents | Tiles |
|---|---|---|
| Characters | 1 through 9 | 36 |
| Circles | 1 through 9 | 36 |
| Bamboo | 1 through 9 | 36 |
| Winds | East, South, West, North | 16 |
| Dragons | White, Green, Red | 12 |
Many rules replace ordinary fives with red fives that count as dora. Their number varies. Fourteen tiles at the end of the wall form the dead wall, which contains replacement tiles and dora indicators.
What completes a win?
A standard hand contains four melds and one pair. Seven Pairs and Thirteen Orphans use special structures. A player normally holds 13 tiles and completes 14 by drawing or claiming an opponent’s discard.
Riichi adds a necessary condition: the hand needs a yaku. A yaku is a recognized winning condition such as Riichi, Fully Concealed Self-Draw, a Value Honor, All Simples, Pinfu, or Pure Straight. Dora without any yaku does not permit a win.
Useful first yaku include:
- Riichi: declare while closed and at tenpai.
- Fully Concealed Self-Draw: win by self-draw without an open call.
- Value Honor: a pung or kong of a dragon, seat wind, or round wind.
- All Simples: use only suited tiles 2 through 8; whether it may be open depends on the rules.
- Pinfu: a closed all-sequence hand with a non-value pair and two-sided wait.
How does riichi work?
A closed player at tenpai can normally declare riichi, identify the declaration discard, and place a 1,000-point stick. Riichi supplies one han and can unlock ippatsu and ura-dora value when the hand wins.
The cost is commitment. After declaring, the player generally discards each draw without changing the hand, and concealed kongs are restricted. Riichi is therefore an exchange: reveal that you are ready and surrender flexibility for value and pressure.
Why is dora not a yaku?
The tile after the dora indicator is the dora. For example, a 4 Characters indicator points to 5 Characters, and a 9 Circles indicator wraps to 1 Circle. Winds cycle East–South–West–North, while dragons cycle White–Green–Red. Red, kan, and ura-dora can add further han.
Each dora normally adds one han, but only to a hand that is already allowed to win. First identify a yaku; count dora second.
What is furiten?
If any tile in the current wait appears among your own discards, you are in discard furiten. You cannot win on another player’s discard, although you may still self-draw. Passing a valid discard win can create temporary same-turn furiten; passing after riichi has a stricter continuing effect.
Furiten applies to the whole set of winning tiles. If a hand waits on 3 and 6 Characters and the player previously discarded either one, the player cannot ron the other. This rule also makes each player’s discard row valuable defensive information.
What is the most common calling mistake?
Chow and pung can reduce shanten or secure a Value Honor, but an open hand cannot riichi and loses closed-only yaku. The classic beginner mistake is calling quickly and discovering at tenpai that the hand has no yaku.
Before calling, check:
- Which yaku is guaranteed after the call?
- Does the call reduce shanten or clearly improve the wait?
- Does the speed compensate for lower value?
- If an opponent declares riichi, how many defensive tiles remain?
A decision order for your first game
- Identify round wind, seat wind, dora, and red-five rules.
- Mark completed melds, pairs, and two-sided blocks.
- Preserve or reduce shanten instead of breaking the hand for one dora.
- Name the post-call yaku before every call.
- At tenpai, list every winning tile and check furiten before comparing riichi and damaten.
- Reassess attack and defense after an opponent’s riichi; pure tile efficiency is no longer the only objective.
Scope and limitations
This introduction is for first-time Riichi players and players transferring from Taiwanese or Cantonese Mahjong. It is not a complete yaku list, fu lesson, or platform regulation. Formal play follows the organizer’s current document; online players should check red fives, open tanyao, dealer repeats, draws, and placement settings.
What can Tingpai Lab train?
Tingpai Lab can train shanten, effective draws, pair choice, and shape preservation in standard hands. In Riichi, add yaku, dora, furiten, value, placement, and defense. A useful process is to identify pure tile-efficiency candidates first, then ask whether each has a yaku, is furiten, and fits the game state.
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