Japanese Mahjong scoring rules are used for Japanese Mahjong, a game for four players common in Japan. The rules were organized in the Taishō to Showa period as the game became popular.
The scoring system uses structural criteria as well as bonuses. Players start with 20,000 to 30,000 points. Scores are counted using sticks of 10,000 points, 5,000 points, 1,000 points and 100 points. A game often ends when all the points of a player are lost, which is a situation called hakoten, dobon, buttobi, etc.
There are two criteria in determining the winning points: han and fu, which correspond to a points table. Han is the unit for the value of yaku, which are particular patterns or conditions of a hand. Fu is the value of melds, waits and "going out".
The payment to the winner of a hand is calculated as follows:
In the case of a draw, points are transferred according to the nōten bappu rule. In the event of a penalty, such as claiming a win with an illegal hand, then points are transferred via the chombo rule.
The total number of han (飜) of all the kinds of yaku (役; winning hand) in the hand is summed up. Each dora (ドラ) increases the han value of a hand. Dora are not regarded as yaku, and no hand can be won without a yaku even if there are some dora tiles.
If there is more than one way to arrange the winning hand, the arrangement with the highest han is used. For example, a hand could be either ryanpeikou (二盃口) or chītoitsu (七対子), but since ryanpeikou is three han where chītoitsu is two han, ryanpeikou should prevail. Some yaku have their han value reduced by one if the hand is not closed.
If a hand has five han or more, it is always counted by mangan (満貫) as a unit and it is not necessary to calculate fu (符) or basic points.
Fu (符) is counted in the order below and then rounded up to the tens. There may be variations of rules for counting it.
[Three han with 70 fu or more] and [four han with 40 fu or more] yield more than mangan and there is no need to calculate basic points.
The list for the third step:
nonterminal or honor tiles  terminal or honor tiles  
minkō (明刻), or minkōtsu (明刻子) (open same three tiles meld, an open triplet) 
2 fu  4 fu 
ankō (暗刻), or ankōtsu (暗刻子) (closed same three tiles meld, a closed triplet) 
4 fu  8 fu 
minkan (明槓), or minkantsu (明槓子) (open same four tiles meld, an open kan) 
8 fu  16 fu 
ankan (暗槓), or ankantsu (暗槓子) (closed same four tiles meld, a closed kan) 
16 fu  32 fu 
shuntsu (順子) (sequential meld, a run) 
0 fu  
toitsu (対子) (two tiles group, the pair) 
2 fu for seat wind tiles, prevailing wind tiles or dragon tiles. 4 fu (or 2 fu in some rules) when the seat wind and prevailing wind match. 0 fu for other tiles 
The list for the fourth step:
ryanmenmachi (両門待ち) (sequential tile waits for both sides) 
0 fu 
kanchanmachi (嵌張待ち) (sequential single tile waits for a middle tile) 
2 fu (waiting for one kind of tile) 
penchanmachi (辺張待ち) (sequential single tile waits for a right or left side (number 3 or 7)) 

tankimachi (単騎待ち) (single tile waits for two pieces meld) 

shanponmachi (双碰待ち) (waits for either of melds of same three tiles) 
0 fu However, a triplet is made, so 2, 4, or 8 fu of melds is added 
The basic points of a hand is calculated as follows:
The actual points given are rounded up to the nearest 100. Even if the values of han and fu are the same, the points received for selfdraw wins often slightly deviate from those received for discard wins because of rounding.
Example 1: The player on the right of the dealer goes out by selfdraw. (The dealer's wind is always East in Japanese rules.) The winner's hand is closed and has a closed triplet (ankō) of Souths. The player also has two Whites as the pair (toitsu) and the winning tile is a White. The yaku are "selfpick" (menzenchintsumohō) and "honor tiles" (yakuhai), and they yield a total of two han. The sum of fu is 20 (fūtei) + 8 (a closed triplet of Souths) + 2 (a pair of Whites) + 2 (pair wait) + 2 (selfdraw) = 34 fu, rounded up to 40 fu.
The basic points are thus 40 x 2^{(2+2)} = 640. The dealer pays the winner 640 x 2 = 1,280, rounded up to 1,300 points. The other two nondealers pay the winner 640, rounded up to 700 points.
Example 2: The same player goes out by the same hand, except this time the winning tile was discarded by the player on the right. The resulting hand has one han of honor tiles. The number of fu is 20 (fūtei) + 10 (ron with a closed hand) + 8 (a closed triplet of Souths) + 2 (the pair of Whites) + 2 (pair wait) = 42 fu, rounded up to 50 fu.
The basic point is thus 50 x 2^{(2+1)} = 400. The discarder pays the winner 400 x 4 = 1,600 points. The other two players pay the winner nothing.
It is possible for a hand to have one han with 102 fu (rounded up to 110 fu) if the rules allow a pair to have four fu when it is made of wind tiles that are both the seat wind and the prevailing wind. Some rules consider that such a pair is still worth two fu, making the hand have exactly 100 fu.
An example of a hand that has one han with 110 fu. , closed , closed , winning by a discard .
The hand has yakuhai of one han with 20 fu of fūtei, 10 fu of menzenkafu, 32 fu of ankan, 32 fu of ankan, four fu of minkō, and four fu of toitsu. East is both the player's seat wind and the round's prevailing wind in this case. This is the largest amount of fu that a hand with one han can have.
Since the method of calculating a winning hand's score in mahjong is quite tedious, many players refer to a scoring table to look up the final score of a hand. Expert and professional players have this table memorized and can thus tell the value of a hand at a glance.
Dealer  Han/Fu  Nondealer  

4 han  3 han  2 han  1 han  1 han  2 han  3 han  4 han  
N/A (2600) 
N/A (1300) 
N/A (700) 
N/A  20 fu  N/A  N/A (400/700) 
N/A (700/1300) 
N/A (1300/2600) 
9600 (3200) 
4800 (1600) 
2400 (N/A) 
N/A  25 fu  N/A  1600 (N/A) 
3200 (800/1600) 
6400 (1600/3200) 
11600 (3900) 
5800 (2000) 
2900 (1000) 
1500 (500) 
30 fu  1000 (300/500) 
2000 (500/1000) 
3900 (1000/2000) 
7700 (2000/3900) 
Mangan  7700 (2600) 
3900 (1300) 
2000 (700) 
40 fu  1300 (400/700) 
2600 (700/1300) 
5200 (1300/2600) 
Mangan 
Mangan  9600 (3200) 
4800 (1600) 
2400 (800) 
50 fu  1600 (400/800) 
3200 (800/1600) 
6400 (1600/3200) 
Mangan 
Mangan  11600 (3900) 
5800 (2000) 
2900 (1000) 
60 fu  2000 (500/1000) 
3900 (1000/2000) 
7700 (2000/3900) 
Mangan 
Mangan  Mangan  6800 (2300) 
3400 (1200) 
70 fu  2300 (600/1200) 
4500 (1200/2300) 
Mangan  Mangan 
To use the table, simply look up the values that correspond to the han and fu counts of the hand. The top numbers in each cell indicate the payout from a player who discards a winning tile. The numbers in brackets indicate the payout for each player in the event the winning tile is selfdrawn. If the winner is the dealer, each player pays the same amount. If the winner is a nondealer, then the other two nondealers pay the smaller number, while the dealer pays the larger number.
The reason why there are no scores in the 1 han 20 fu cell is that such a hand is impossible. The only 20 fu hands are the nopoints hand (pinfu, 平和) where the winning tile is selfdrawn. However, since a nopoints hand must be closed, it makes winning via a selfdrawn tile automatically add 1 han yaku of self pick to the hand. Therefore, a 1 han 20 fu hand cannot exist.
As stated above, a seven pairs hand is worth 25 fu. Since the hand is always closed, it adds 1 han yaku of self pick when won by selfdraw.
When it is clear that a hand reaches basic points of more than 2,000, it is limited to full basic points of 2,000 and called mangan (満貫). A hand of five han or more is always counted as a multiple of mangan. In those cases there is no need to calculate basic points.
One han cannot reach mangan because 110 fu x 2^{(2+1)} = 880 < 2,000. (With one han, 110 fu is the maximum.)
Two han cannot reach mangan because 110 fu x 2^{(2+2)} = 1,760 < 2,000. (With two han, 110 fu is also the maximum.)
When a hand has 120 fu or more, it always has some yaku of three han or more.
Name  Han value  Point value  

Mangan  3 han, 70 fu or more; 4 han, 40 fu or more; 5 han 
1 x mangan  12,000 (dealer) 8,000 (nondealer) 
[Three han with 70 fu or more] is mangan as 70 x 2^{(2+3)} = 2,240 > 2,000. The basic points become 2,000.
[Four han with 40 fu or more] is mangan as 40 x 2^{(2+4)} = 2,560 > 2,000. (In some rules [four han with 30 fu] is regarded as mangan because 30 x 2^{(2+4)} = 1,920 is close to 2,000. [Three han with 60 fu] is the same.) Five han is automatically mangan irrespective of fu since 20 fu x 2^{(2+5)} = 2,560 > 2,000. 

Haneman  6 or 7 han  1.5 x mangan  18,000 (dealer) 12,000 (nondealer) 
A 6 or 7 han hand is considered haneman (跳満, or hanemangan 跳満貫) and the basic points are 3,000. 

Baiman  8−10 han  2 x mangan  24,000 (dealer) 16,000 (nondealer) 
An 8−10 han hand is considered baiman (倍満, or baimangan 倍満貫) and the basic points are 4,000.  
Sanbaiman  11 or 12 han  3 x mangan  36,000 (dealer) 24,000 (nondealer) 
An 11 or 12 han hand is considered sanbaiman (三倍満, or sanbaimangan 三倍満貫) and the basic points are 6,000.  
Kazoeyakuman  13 or more han  4 x mangan  48,000 (dealer) 32,000 (nondealer) 
In most rules, a hand with 13 han or above is considered kazoeyakuman (数え役満; counted yakuman). It has the same scoring as yakuman (役満).  
Yakuman  Limit  4 x mangan  48,000 (dealer) 32,000 (nondealer) 
A yakuman (役満, or yakumangan 役満貫) is awarded to some rare hands which are particularly hard to achieve, like kokushimusō (国士無双; thirteen orphans) or sūankō (四暗刻; four closed melds of the same three tiles). The basic points are 8,000.  
Multiple yakuman  Multiple limit  NA  Multiplied yakuman value 
If the winning hand can be interpreted as combined forms of rare hands, multiple yakuman points are awarded. For example, a hand consisting of four closed quads of wind tiles plus a pair of dragon tiles would be worth six yakuman. 
In plenty of occasions, a hand ends with all tiles drawn and the 14tiles in the dead wall remain. Yet, no player wins the hand. This is the exhaustive draw. In this case, points may be exchanged barring any tenpai hands vs nōten hands. After each exhaustive draw, the counter increases by one.
Tenpai (聴牌) means one tile short of a winning hand. To be tenpai, a hand does not need any particular yaku partly because winning by the last discard is yaku itself. When a hand is not tenpai, the situation is called nōten (ノー聴: nō is English "no" and ten for tenpai).
Players must show their hand to verify that it is tenpai when a hand is a draw and if they declared rīchi or if they declare tenpai. If a hand with rīchi declaration is nōten, a chombo penalty is imposed. In some cases, a player who didn't declare rīchi can declare nōten even when the hand is tenpai to keep their hand concealed.
Players receive or pay points called nōten bappu (ノー聴罰符; fu of penalty for nōten) in the following way, when a hand ends in an exhaustive draw:
In most rules when a dealer's hand is nōten, the dealer changes and the game wind may change. But if it's the last hand of the last round, in some rules, a game does not end if the dealer declares nōten.
When there are counter sticks (honba) on the table, winners get bonus points calculated by multiplying 300 by the number of those counters. Honba (本場) is a unit of continuous dealer wins and draws, and to be exact, hon (本) is a unit of numbers of some bars and so on, and ba (場) means a scene or a situation.
The dealer keeps count of the number of continuous dealer wins and draws by placing point sticks on the table. While point sticks are usually used for scoring, here they are used merely as counters, a visual aid. The initial count is zero. The number of counters increases by one when:
In the case of (1) or (3), the dealer remains the same. In the case of (2), when the dealer cannot declare tenpai, the dealer changes, but the number of counters increases regardless of whether the dealer declares tenpai. In all other cases, namely when only a nondealer wins, the count is reset to zero.
Renchan (連荘) is a situation in which a player successively plays the dealer, and is often only caused by dealer's win or tenpai; therefore, draws are not always renchan. On the other hand, the number of honba always increases when a draw or a dealer's win occurs. If the dealer changes, it is called rinchan (輪荘) instead of renchan, and happens for example by their nōten in the case of a draw.
In a state of n counters (suppose n is a number), when a player wins a hand by selfdraw (tsumo), the player gets a bonus of n x 100 points from each of other three players for a total of n x 300, and when a player wins by claiming a discard (ron, 栄), the player gets a bonus of n x 300 from the discarder.
There is a rule in which players must have two han or more from yaku when the count is five or more, which is called ryanhanshibari (二飜縛り; literally "twohan binding").
There may be some variation of the rules.
Example:
In the optional rule wareme (割れ目, ワレメ; fissure, split), the player in front of whom the wall was split to indicate the end of the dead wall, acquires and pays double the normal points. They are doubled after the points for counters are added. It is often especially called oyaware (親割れ; parent's wareme) when the player is the dealer.
Under the rule of chombo (チョンボ, 錯和 or 冲和), a player pays a penalty of the same amount as mangan to other players in most rules. A nondealer pays 4,000 to East and 2,000 to the other two players, while a dealer pays 4,000 to each. Chombo occurs for any of the following:
Note that false rīchi and invalid kan after rīchi are caught only after draws or winning declarations by players who declared the rīchi.
Any rīchi bets are returned to the players after the end of a chombo hand.
After the game is finished, the points of each of the three players other than the winner is rounded off to the nearest 1,000. The winner's points are the difference between 120,000 (30,000 x 4) and the total of these three players' points. The number of points is divided by 1,000, and 30 is finally subtracted from it. The sum of these final points is always zero. In most cases there are additional points transferred based on the players' final places (uma). (For example: 1st gets +20, 2nd gets +10, 3rd gets 10 and 4th gets 20)
Example: The initial points are 25,000 each. A (winner): 43,600, B: 14,500, C: 15,400, D: 26,500, and rounded off to B:15,000, C:15,000, D:27,000. The number of the winner's points is calculated as follows irrespective of initial points: 120,000 − (15,000 + 15,000 + 27,000) = 63,000 (There sometimes happens the case like this. The result of the winner differs from 64,000 that was counted rounding 43,600 off and adding 4 x 5,000 (difference between 30,000 and initial points)). The final points and place: A:+33 (1st), D:−3 (2nd), C:−15 (3rd), B:−15 (4th). The 1st place is also counted like: (30 − 15) + (30 − 15) + (30 − 27) = +33.