WSOM Rulebook

The Mahjong Tiles

  1. The World Series of Mahjong uses a set of 136 tiles. The bonus tiles (Flowers and Seasons) are not used.
  2. The 136 tiles are composed of 34 different designs, with 4 tiles for each design.
  3. The 34 designs are separated into two groups: the number tiles, and the honor tiles.
  4. Number tiles: The number tiles are in three suits: BamboosCharacters and Dots. Each suit has nine designs, numbered 1 to 9. Thus there are a total of 27 different designs of suit tiles, with 4 tiles for each design.
  5. Honor tiles: Honor tiles consist of four Winds: “East”, “South”, “West”, and “North”, plus three Dragons: “White”, “Green”, and “Red”, for a total of seven different designs, with 4 tiles for each design.
  6. Terminal tiles: The “1” and “9” number tiles (total 6 designs) are summarily called terminal tiles, and the “2” to “8” number tiles (total 21 designs) are called middle tiles. In common usage, the term “terminal tiles” is sometimes meant to include the honor tiles, and sometimes not. In these rules, when there is a need for clarity, the terms “terminal number tile” and “terminal and/or honor tile” will be used.

Game Objective

The mahjong competition consists of a number of hands. In a hand, through a process of drawing and discarding, the players compete to be the first to complete a winning hand. The winner of the hand receives points from the other players, but the amount of points earned varies greatly according to the content of the winner’s hand. Therefore, winning high-scoring hands (and preventing the opponents from winning high-scoring hands) is the key to victory. A player’s result and ranking is determined by his total points won and lost over a number of hands.

Play Procedure

When play begins, the four players go through a “selection of seats” procedure to assign their seats and choose the starting East player. After that, the specified number of hands is played. Each hand follows these steps:

  1. Shuffle, break the wall, deal the tiles
  2. Draw and discard
  3. If someone wins the hand, perform scoring for the winning hand.
  4. If the wall is exhausted without anyone winning, the hand is a draw, and all players score zero for the hand.

Sequence, Triplet, Kong, Pair

  1. Sequence: A sequence is three tiles of consecutive numbers in the same suit. Three such tiles in the concealed hand is a “concealed sequence”; an “exposed sequence” is formed by claiming a “chi”.
    Example:
     
  2. Triplet: A triplet is three identical tiles: either three same-numbered tiles in the same suit, or three identical honor tiles. Three such tiles in the concealed hand is a “concealed triplet”; an “exposed triplet” is formed by claiming a “pong” (or a “win on discard”).
    Example:
     
  3. Kong: Four identical tiles can be declared to form a kong. (See the section “Kong” below.) Four identical tiles in the concealed hand are not considered a kong; they constitute only a concealed triplet (plus an extra tile).
    (Since “kong” is a Chinese word, its plural form should be conjugated the Chinese way: just “kong”.)
    Example:
  4. Pair: Two identical tiles are called a pair.
    Example:

Winning Hand

  1. There are two types of winning hands: the Regular Hand and the Irregular Hand.
  2. Regular Hand: The regular hand consists of 4 sets (each set being a sequence, a triplet, or a kong) and a pair (called the “eyes”).
  3. Irregular Hand: There are two of them: “Thirteen Terminals” and “Seven Pairs”.
  4. A hand must conform to either a regular hand or an irregular hand in order to win (go out). All patterns listed in the “Scoring” chapter, except for the irregular hands under category 10, are not definitions of the winning hand. In other words, one cannot win just by meeting the condition of a pattern, without meeting the requirements of a winning hand. (Such will be considered a “false win”.)

Dice Count

In the “picking seats” and “breaking the wall” procedures below, the “dice count” is needed. The count is taken counter-clockwise around the table, starting with the thrower of the dice as “1”, and finishing with the number which is the sum of the dice. That seat is the result of the dice count. In other words, a dice roll of “5” and “9” gives the dice thrower; “2” “6” and “10” gives his lower seat; “3” “7” and “11” gives his opposite seat; “4” “8” and “12” gives his upper seat.

In each throw of the dice, two six-sided dice (with faces numbered 1 to 6) are used.

Picking Seats

As specified by the Tournament Format, at the beginning of each quarter or half, the four players at the table will pick their seats randomly (and also determine the starting East) according to the following procedure:

  1. The four players sit around the table arbitrarily.
  2. Take one each of the Wind tiles (East, South, West, North). Turn the four tiles face down, shuffle them, and arrange them in a line.
  3. Take an odd number tile and an even number tile, and add them (face up) to the two ends of the line, sandwiching the Wind tiles and making a row of six tiles.
  4. An arbitrary player throws the dice. The player indicated by the dice count throws the dice again. The player indicated by the second dice count will be the one who first takes a Wind tile.
  5. If the second dice throw is an odd number, the Wind tiles will be taken starting from the end with the odd number tile; if it is an even number, the Wind tiles will be taken starting from the end with the even number tile. Starting from the player indicated by the second dice count and going counter-clockwise, each player in order takes a Wind tile.
  6. The player who gets the “East” tile is the starting East player, and takes the seat at the table indicated as “East”. The player with the “South” tile takes his lower (right) seat; the player with the “West” tile takes his opposite seat; the player with the “North” tile takes his upper (left) seat.

The Dealer and the Seat Wind

  1. In a hand, each seat (player) belongs to a certain Wind direction: East, South, West, and North (in counter-clockwise order).
  2. Seat Wind: The Wind tile which corresponds to one’s seat direction is one’s Seat Wind. The other winds are called “Non-Seat Winds”. “Seat Wind” is a category 3 (Honor Tiles) pattern, and is worth points. When the deal passes (see below), the Seat Wind rotates accordingly. (Note: Each player’s Seat Wind is determined solely according to the passing of the deal, and is never affected by the dice thrown when “breaking the wall”.)
  3. Dealer: The East player is sometimes also called the “dealer”. The other players are called “non-East players”.
  4. Cycle: The tournament is played in cycles, each cycle being four hands. In the first hand in a cycle, the player who has picked the East seat becomes the starting East (unless otherwise specified), who is the dealer for the first hand.
  5. Passing the deal: After a hand is completed, the South player in the previous hand becomes the new East player in the next hand. In this way, in a cycle each player has one chance to become the dealer.
  6. In the World Series of Mahjong Rules, the “Prevailing Wind” (Round Wind) is not recognized. Also, the deal always passes (East never repeats the deal). The dealer has the advantage that he plays first in the hand, but enjoys no additional privileges in scoring.

Breaking the Wall

The following “single cast” (of the dice) procedure is used for automatic mahjong tables. (In case hand-shuffling is needed, please follow the judge’s instructions.)

  1. East throws the dice. The player indicated by the dice count is the “wall breaker”. Also, the thrown number is the “break count”.
  2. From the wall in front of the wall breaker, count a number of stacks off the right end (in a clockwise direction) equal to the break count. These stacks should be shifted away slightly, and their (left) end becomes the “kong box”. The stacks to the left of the split become the live wall.
  3. Notice that tiles are taken off the live wall in a clockwise direction, which is different from the counter-clockwise direction of play.

(Note: Each player’s Seat Wind is determined solely according to the passing of the deal, and is never affected by the dice thrown when “breaking the wall”.)

The Deal

After breaking the wall, the players will be dealt their initial hands.

  1. East starts by taking two stacks (four tiles) from the live wall. Then South, West and North, in order, each takes two stacks.
  2. The above is repeated two more times, so that each player now has 12 tiles.
  3. East now takes the first and fifth tiles from the live wall. Then South, West and North, in order, takes one tile each.
  4. At this point, East should have 14 tiles, and every non-East player should have 13 tiles. The deal is complete, and East commences play.
  5. Until the deal is finished and the players have confirmed that they have received the right number of tiles, one should not look at their tiles or feel their bottom surfaces. Otherwise, one may be penalized for making a mistake in the deal. (This rule is to prevent someone from deliberately claiming a misdeal after seeing that his tiles are not good.)

The Play

  1. East starts the hand by discarding a tile.
  2. The players then, in turn, draw a tile from the live wall, and then discards a tile.
  3. The above sequence is interrupted when someone claims a discard.
  4. Play continues until either someone wins the hand, or the hand ends in a draw with the wall being exhausted.

Claiming a Discard

  1. A discarded tile may be claimed by another player to complete a winning hand or a set.
  2. Only the last discarded tile may ever be claimed. Once the next player has drawn and discarded, the previous discard may no longer be claimed.
  3. When one claims a discard to complete a set, the entire set must be displayed as exposed. One may not take the discard into his concealed hand.
  4. There are four types of claims: win, chi, pong, kong (big exposed kong). These will be detailed below.

Winning the Hand

  1. Calling: A hand which is one tile from completion of a winning hand is a calling hand, and it is said to be calling for the tiles which will complete the hand.
  2. Self-draw Win: If a player completes his winning hand by drawing a tile from the wall, this is called a self-draw win. (“Win on Kong” is naturally a self-draw win.) The winner should announce “fu” or “tsumo”.
  3. Win on Discard: If an opponent discards a tile one is calling for, one can announce “fu” and claim the discard to complete his hand. This is called a win on discard, and the player who discarded the winning tile is called the discarder. (“Robbing a Kong” is considered a win on discard.)
  4. In principle, one can win in all cases as long as he has completed a winning hand. While there is the “Rule of Same-Turn Immunity” in the “Scoring System” chapter, the World Series of Mahjong does not adopt any “sacred discard” rule or such which prohibits the player from winning with a completed winning hand in certain cases (“penalty tiles” excepted). Similarly, there are no such prohibition rules for Pong or other claims.

Pong

  1. If an opponent discards a tile which matches a pair in one’s hand, one may announce “pung” and claim the discard to form an exposed triplet with the pair.
  2. The three tiles which compose the exposed triplet must be revealed and displayed as a set to the upper left of one’s concealed hand. (The set should be placed in clear view of all the players, and should not be placed back at the corner of the table.) One of the tiles should be rotated 90 degrees (to a horizontal position) to indicate which player made the discard: if the upper seat discarded, rotate the left tile; if the opposite seat discarded, rotate the middle tile; if the lower seat discarded, rotate the right tile. The three tiles in the exposed triplet are thereafter locked in the set, and cannot be taken into the concealed hand or rearranged (except be extended into a “small exposed kong”).
  3. After claiming a pung, the player discards a tile. Then his lower seat takes his turn and draws a tile.

Chi

  1. If one’s upper seat discards a tile which can complete a sequence with two tiles in one’s hand, one may announce “chi” and claim the discard to form an exposed sequence with those two tiles. Unlike “pong” or “win”, one may “chi” only a tile discarded by one’s upper seat.
  2. The three tiles which compose the exposed sequence must be revealed and displayed as a set to the upper left of one’s concealed hand. The three tiles should be arranged in numerical sequence from left to right, and the claimed tile should be rotated 90 degrees (to a horizontal position) to indicate that it is the tile discarded by the upper seat. (Unless it is the smallest-numbered tile in the set, the rotated tile should not be put on the left end of the set, which disrupts the numerical order.) The three tiles in the exposed sequence are thereafter locked in the set, and cannot be taken into the concealed hand or rearranged.
  3. After claiming a chi, the player discards a tile. Then his lower seat takes his turn and draws a tile.
  4. After announcing “chi”, it is permissible (but not recommended) to first discard a tile, and then to reveal the exposed sequence. The “chi” procedure is considered complete only when both steps are finished; until then, the clocking runs against the claimant. The other players should wait for him to display the exposed sequence before drawing a tile or claiming the discard (except for winning).

Kong

  1. Four identical tiles can be declared to form a kong. There are three kings of kong declarations: “concealed kong”, “small exposed kong” and “big exposed kong”. The claimant should announce “kong”.
  2. Concealed Kong: If a player has four identical tiles in his concealed hand, he may declare and form a concealed kong with them. One may declare a kong on one’s own turn, after having drawn a tile from the wall (or immediately after the deal for East, or after drawing a supplement tile), but not immediately after claiming chi or pong. The player first reveals the four tiles to show that they are indeed identical. Then he displays them as a set to the upper left of his concealed hand. The two middle tiles should be placed face up, while the tiles at both ends be turned face down (to indicate a concealed kong). Then he draws a supplement tile.
  3. Small Exposed Kong: If a player has a tile in his concealed hand which matches his own exposed triplet, he may declare and form a small exposed kong with them. One may declare a small exposed kong under the same timing as a concealed kong: on one’s own turn, after having drawn a tile from the wall (or after drawing a supplement tile). After announcing “kong”, the player reveals the hand tile and adds it to one end (not adjacent to a horizontal tile) of his exposed triplet to form an exposed kong. (Alternatively, one may add the tile horizontally atop the horizontal tile, so that the two horizontal tiles are lined up together side by side.) Then he draws a supplement tile. Note that one must announce “kong” before revealing his hand tile. Otherwise the judge may rule it as a discarded tile, in which case the lower seat may claim it for “chi”.
  4. Big Exposed Kong: If an opponent discards a tile which matches one’s concealed triplet in hand, one may announce “kong” and claim the discard to form an exposed kong with the concealed triplet. The four tiles which compose the exposed kong must be revealed and displayed as a set in front of one’s concealed hand (in the space between the concealed hand and the wall). One of the tiles should be rotated 90 degrees (to a horizontal position) to indicate which player made the discard: if the upper seat discarded, rotate the left tile; if the opposite seat discarded, rotate one of the middle tiles; if the lower seat discarded, rotate the right tile. Afterwards, the player draws a supplement tile.
  5. If an opponent discards a tile which matches one’s exposed triplet, one may not declare a kong with the discard.
  6. Once a kong is declared with four identical tiles, these four tiles are thereafter locked in the set, and cannot be taken into the concealed hand or rearranged.
  7. Supplement Tile: After declaring a kong, one should take a supplement tile from the “kong box”. (Because a kong uses up 4 tiles for a set which is normally 3 tiles, the hand becomes one tile short and needs to be replenished.) After taking a supplement tile, the player discards a tile. Then his lower seat takes his turn and draws a tile.
    The player must first reveal the four tiles which constitute his kong to be confirmed by the other players before drawing a supplement tile. Drawing a supplement tile before revealing the kong is prohibited, and may be ruled as a “long hand”.
  8. Winning on the supplement tile is called “Win on Kong”. “Win on Kong” is considered a self-draw win.

Robbing a Kong

  1. When an opponent declares a “small exposed kong”, and one is calling for the tile which is being declared as a kong, one can announce “fu” and claim the declared tile to complete his hand. This is called “Robbing a Kong”. Robbing a Kong is considered winning on discard, and the player who tried to declare the kong is the discarder.
  2. “Robbing a Kong” is a category 9 pattern, and is worth points.
  3. Only a small exposed kong can be robbed. A concealed kong cannot be robbed, with no exceptions. Against a big exposed kong, the “win” claim takes precedence according to the “Precedence of Claims” rules, and the “kong” claim is cancelled.
  4. A player can announce “fu” and rob the kong as soon as the opponent adds his tile to the exposed triplet; one needs not (and should not) wait for the opponent to draw a supplement tile before robbing a kong. If a player wants to discard a tile without declaring a kong, he should place the tile cleanly in the designated position in the river, and not ambiguously in the area of his exposed tiles.

Precedence of Claims

  1. When two or more players want to claim the same discarded tile, the below order of precedence is observed. The claim with the highest precedence alone gets the discard, and the other claims are cancelled.
  2. The order of precedence, from high to low, is as follows:
    • 1a. win by the discarder’s lower seat
    • 1b. win by the discarder’s opposite seat
    • 1c. win by the discarder’s upper seat
    • 2. pung, kong (big exposed kong)
    • 3. chi

When two players announce “win” together, the single winner is determined as above; this is called interception. Note that there are no exceptions to this rule.

The Dead Wall and the Seabed Tile

  1. Dead Wall: The last 14 tiles in the wall are called the “Dead Wall”, and are not played.
  2. Late in a hand, any player may request that the “wall breaker” pushes the 14-tile Dead Wall slightly to the left, separate from the live wall, so that it is easier to tell how many tiles are left to play. If, due to a supplement tile having been taken, a lone tile stands as “half a stack” in the kong box, the 7th stack from the end should be broken up, with the lower tile in the stack placed with the Deal Wall, and the upper tile in the stack placed at the end of the live wall, as the seabed tile.
  3. Seabed tile: The last tile in the wall before the Dead Wall (i.e. the 15th last tile in the wall) is called the seabed tile. The player who draws the seabed tile may not declare a kong, and must discard a tile unless one is winning. This discard is called the riverbed tile.
  4. Riverbed tile: The riverbed tile may not be claimed for chi, pong or kong; it may only be claimed for a win.
  5. Winning on the seabed tile or the riverbed tile are worth points.
  6. No Win: If no one wins on the riverbed tile, the hand is a draw, and all players score zero for the hand. The deal (East) always passes after each hand.

WSOM Mahjong Scoring System

13 tiles to play, 14 tiles to Mahjong

Limit

Compound Limit Hand: 320 points
If the hand contains multiple patterns which totals to 320 points or more, it will only score as 320 points, with the exception below:

Single Limit Hand: 480 points
If a single pattern scores 400 or 480 points, then the hand will score 400 or 480 points respectively.

Calculating the value of hands:
In WSOM the only scoring unit is the point system by an additive rule. The final score of the hand is simply the sum earned by its composing patterns. Possible conversions to monetary values are not a rule-specific issue, but – if necessary – must be negotiated by the players before the game is started.

With the exception of 5, only one hand from one set (e.g. all of 4A, 4B, 4C) can be counted, and counted only once.

1 All Sequences: 5

Concealed Hand: 5

No exposed sets. Concealed Kong okay. Winning on discard okay.

No Terminals: 5

4A Mixed One-Suit: 40

4B Pure One-Suit: 80

4C Nine Gates: 480


Winning on any one of

Value Honor (番牌) : 10 per set

A triplet/kong of Seat Wind or Dragons

6A Small Three Dragons: 40

6B Big Three Dragons: 130

6C Small Three Winds: 30

6D Big Three Winds: 120

6E Small Four Winds: 320

6F Big Four Winds: 400

6G All Honors (字一色) : 320

All Triplets: 30

8A Two Concealed Triplets: 5

8BThree Concealed Triplets: 30

8C Four Concealed Triplet: 125

9A One Kong: 5

9B Two Kong: 20

9C Three Kong: 120

9D Four Kong: 480

10A Two Identical Sequences: 10

10B Two Identical Sequences Twice: 60

10C Three Identical Sequences: 120

10D Four Identical Sequences: 480

11A Three Similar Sequences: 35

11B Small Three Similar Triplets: 30

11C Three Similar Triplets: 120

12A Nine-Tile Straight: 40

12B Three Consecutive Triplets: 100

12C Four Consecutive Triplets: 200

13A Mixed Lesser Terminals: 40

13B Pure Lesser Terminals: 50

13C Mixed Greater Terminals: 100

13D Pure Greater Terminals: 400

14A Final Draw: 10

Self-draw win on the last tile in the wall

14B Final Discard: 10

Winning on the final discarded tile. .

15A Win on Kong: 10

Self-draw win on a supplement tile after a Kong.

15B Robbing a Kong: 10

Winning off a player’s Kong upgraded from a melded triplet.

16A Blessing of Heaven: 155

East winning with his initial 14-tile hand. Does not count if East has made a concealed kong.

16B Blessing of Earth: 155

A non-East player calling with his initial 13-tile hand, and winning on East’s very first discard.
Does not count if East has made a concealed kong.

17 Thirteen Terminals: 160

18 Seven Pairs: 30

Calculating the total score

All winning patterns are added, and then multiplied by 3. The winner wins this amount.

If the hand was won by self-draw, the losing players split this amount equally 3 ways.

If the hand was won by a discard, and the winning patterns sum to 25 or less, the losing players split this amount equally 3 ways.

If the hand was won by a discard, and the winning patterns sum to more than 25 points, the two non-discarded players each lose 25 points, and the discarded player loses the rest.

Example: Winning player seat wind is North

Concealed:

Melded:

Player wins:

Mixed One-Suit: 40

All Triplets: 30

Three Consecutive Triplets: 100

No points for Pung of East as it is not the seat wind.

Total: 170 points

If the winning player self-draws, then he or she wins 170 x 3 = 510 points, while the other three players split -170.

If the winning player wins on a discard, then the discarded player loses 460 points while the other two players each lose 25.