Mahjong Rules
Mahjong is a tile-based game of skill, strategy, and calculation for four players. While often compared to Western card games like rummy, it has a distinct structure and greater strategic depth. The objective is to build a complete hand—typically four sets and a pair—before opponents.
Unlike games with a single ruleset, competitive mahjong uses several codified systems. Regional variations exist, but internationally, Japanese riichi mahjong and Mahjong Competition Rules (MCR) are primary standards. Both are used in high-level events, including championships sanctioned by the European Mahjong Association. Understanding their common mechanics is essential to appreciating this classic mind sport.
This overview covers fundamental four-player competitive mahjong rules, focusing on common principles and highlighting distinguishing features of riichi and MCR, which govern most organized tournaments.
Equipment and Setup
A mahjong set contains tiles. A standard competitive set has 136 tiles, divided into suits and honors. The three suits (Characters, Circles, Bamboo) are numbered one through nine, with four identical copies of each (27 suited tiles).
Honor tiles include four Wind tiles (East, South, West, North) and three Dragon tiles (Red, Green, White), each with four copies. Japanese riichi uses this 136-tile composition. MCR adds eight bonus tiles (four Flowers, four Seasons) which provide bonus points but don’t form sets.
Players are assigned a seat wind (East, South, West, North); East is the dealer. Tiles are shuffled face-down and built into four two-tier “walls.” The dealer starts with 14 tiles, others with 13. Play proceeds counter-clockwise.
The Objective of the Game
The goal is to be the first to assemble a complete 14-tile hand: four sets and one pair. This is the standard winning hand structure, though rare non-standard hands exist.
A valid hand requires a pair and four sets. Sets are:
- Pung: Three identical tiles (e.g., three Red Dragons).
- Kong: Four identical tiles. Functions as a set but requires drawing an extra replacement tile to maintain 14 tiles.
- Chow: A sequential run of three tiles in the same suit (e.g., 4, 5, 6 of Bamboo). Honor tiles cannot form a chow.
A pair is two identical tiles. The first player to form this structure and legally declare a win ends the hand.
Gameplay and Turn Structure
Play starts with the dealer (East) discarding a tile. The turn passes right (South). A basic turn involves drawing one tile from the wall, then discarding one face-up. This continues around the table.
Game interaction comes from claiming discards. When a player discards, others may claim it to complete a set, interrupting turn order. The claim is verbal (“Chow,” “Pung,” “Kong,” or winning call), and the set is exposed.
- A Chow can only be claimed from the player to your left.
- A Pung or Kong can be claimed from any player’s discard; play skips to the claiming player.
- A winning tile can be claimed from any player’s discard (winning by “ron”).
A player can also win by drawing their final tile from the wall (self-drawn win, or “tsumo”). After a win, the hand is scored, and points exchanged.
Key Rules of Japanese Riichi
Japanese riichi mahjong features distinct rules promoting defensive play. An essential requirement is a yaku, a specific scoring pattern. A hand is invalid without at least one yaku, preventing wins with random hands and enforcing strategic goals. Incorrectly declaring a win without a yaku incurs a penalty.
The iconic “riichi” declaration is a yaku. A player with a fully concealed hand, one tile from completion (tenpai), can declare “riichi.” They place a 1,000-point stick as a deposit and discard sideways. Once in riichi, they cannot change their hand, automatically discarding any drawn tile that doesn’t complete it. Winning after declaring riichi earns the riichi yaku.
Riichi also includes dora, bonus tiles adding value but not counting as a yaku. Dora is determined by an indicator tile on the wall (e.g., 2-of-Circles indicator makes 3-of-Circles dora). A hand with many dora is worthless without a yaku.
A critical defensive rule is furiten: if any potential winning tiles are in a player’s discard pile, that player cannot win on another’s discard. This prevents passing up wins for more valuable ones, adding strategy. For more, see the complete mahjong strategy guide.
| Common Yaku | Description |
|---|---|
| Riichi | A declaration that a concealed hand is one tile from completion. |
| Tanyao (All Simples) | A hand containing no terminal (1 or 9) or honor tiles. |
| Yakuhai (Value Pung) | A pung or kong of Dragon tiles, the seat wind, or the round wind. |
| Pinfu | A concealed hand made entirely of chows with a valueless pair, won on a two-sided wait. |
Key Rules of Mahjong Competition Rules (MCR)
Mahjong Competition Rules (MCR), also known as Chinese Official or International Standard, unify international play. Used in events like the SportAccord World Mind Games, its cumulative scoring encourages aggressive, open play compared to riichi.
MCR’s central principle is an 8-point minimum for a winning hand. Points are calculated from 81 scoring patterns (fan). There’s no yaku gateway; if components total 8+ points, it’s a valid win.
MCR uses a 144-tile set, including eight Flower and Season bonus tiles. When drawn, a bonus tile is set aside, and a replacement drawn. Each bonus tile adds one point to the final score. Additive scoring and fewer penalties for open hands lead to more pung and chow calls, resulting in faster games.
Ending a Hand
A hand ends when a player declares a valid win or the wall runs out. Upon winning, the hand’s value is calculated, and points exchanged. For a discard win (ron), the discarding player typically pays the full value. For a self-drawn win (tsumo), other players split the payment.
If all drawable tiles are used (except the dead wall) and no one wins, it’s an exhaustive draw (ryuukyoku). Players may reveal hands to show if they were one tile from winning (tenpai). Rules may dictate a small point exchange between tenpai and non-tenpai players before the deal passes.
Strict penalties (chombo) are enforced for major infractions like invalid wins, incorrect tile counts, or revealing wall sections, resulting in significant point deductions paid to other players.
Mahjong vs. Solitaire Puzzles
Many first encounter “mahjong” via computer games like Mahjong Solitaire or Shanghai. These are single-player tile-matching puzzles where players clear layouts by finding and removing identical, unblocked pairs.
These solitaire games use mahjong tiles but share no rules, objectives, or gameplay with the four-player game. They are pattern-recognition puzzles, not strategic mind sports. While familiarizing players with tile designs, they differ entirely from the competitive game. For daily pattern training, a daily logic puzzle offers a different challenge.
Real mahjong is a dynamic contest of calculation, risk assessment, and psychology, ranking it among the world’s great mind sports.
Frequently Asked Questions
How many tiles are in a mahjong set?
Japanese riichi mahjong uses 136 tiles (suits 1-9, Winds, Dragons). Mahjong Competition Rules (MCR) and many Chinese variants use 144 tiles, adding eight bonus Flowers and Seasons. American mahjong includes even more tiles, such as Jokers.
What is the difference between a Pung and a Chow?
A Pung is three identical tiles (e.g., three 5-of-Bamboo). A Chow is a sequential run of three tiles in the same suit (e.g., 2, 3, 4 of Circles). Pungs can be claimed from any player’s discard, while Chows can only be claimed from the player to your immediate left.
Is mahjong a game of luck or skill?
Mahjong combines luck and skill. Tile draws introduce randomness in a single hand. However, over a match, skill dominates. Expert players consistently outperform novices through superior strategy, probability calculation, defensive play, and reading opponents. Long-term success is determined by skill.
What does “riichi” mean in Japanese mahjong?
Riichi is a formal declaration that a player’s concealed hand is one tile from completion (tenpai). The player places a 1,000-point stick and cannot change their hand. This high-risk move adds significant value if they win. The declaration itself is a “yaku,” an essential scoring element for winning in Japanese rules.
Can I claim any discarded tile I want?
No, claims are restricted. You can claim a discard from any opponent to complete a Pung (triplet) or a Kong (quad). However, to complete a Chow (sequence), you may only claim the discard from the player directly to your left. A winning tile can be claimed from any player.
What is MCR mahjong?
MCR, or Mahjong Competition Rules (Chinese Official), is an international standard. It uses a cumulative scoring system based on 81 patterns (fan), requiring a minimum of 8 points to win. MCR promotes a more open and aggressive style of play compared to the defensive Japanese riichi ruleset.
What happens if nobody wins a hand?
If the drawable tiles run out before a win, the hand is an exhaustive draw (ryuukyoku). Players may reveal hands to show if they were “tenpai” (one tile from winning). A small point transfer often occurs between tenpai and non-tenpai players before the deal passes.
Are the rules the same everywhere in the world?
No, mahjong has countless regional and house variations. Rules differ significantly in scoring, valid hands, and legal plays. However, for international competitive play, two major systems are standardized: Japanese riichi and Mahjong Competition Rules (MCR). Most international tournaments use these well-defined rulesets.
Is Mahjong Solitaire the same as real mahjong?
No, they are entirely different games sharing only the tile set. Real mahjong is a complex four-player mind sport involving skill and strategy. Mahjong Solitaire, a single-player matching puzzle on apps, clears tile layouts by finding identical, unblocked pairs. It has no connection to competitive mahjong gameplay.