This page is no longer maintained, however I leave it here because it still serves some use, if only to me, of the hands and rules I played with in college :) Here is a WayBack copy of a much nicer 'intro' page, that has graphical illustrations on what hands look like as well. Some of the hands seem odd to me, but it will help you understand the game. Another archived page, very well done, is Toudai-Shiki Mah Jong page. He gives example hands of almost all the yaku, quite a long page!
definition: Mah Jong

Mah Jong - Modern Japanese Rules

Hi. This is a very loose page for describing game play, the hands, or yaku, in Mah Jong (or Mah Jongg as it is sometimes spelled). It now includes point tables, and many exceptions and extra rules. These yaku are the ones my Japanese friends play with, and basically represent the commonly used Japanese rule set.

This page assumes a basic knowledge of how to play Mah Jong, as in you have played several hands, but you still have no clue what you are supposed to be doing. I am getting better at this game, but I still am far from being the definitive word on Mah Jong. That would be my sensei, Wada-san :-)
I will list several of the definitions and rules that I use. This doesn't mean these are universally used, however. In fact, in the book I have on Mah Jong, several of the rules we play by directly conflict with rules in it. You will find different rulesets and hands, as well as different terminology, in just about every Asian country. Notably, Hong Kong, Taiwan, and Korea, as well as mainland China, all have different ways of playing, scoring, and talking. Suprising, eh? ;-)
You may want to dress informally when playing Mah Jong, and with short sleeves to avoid knocking over tiles and to keep cool (it can get pretty hot).
Jump straight to the score tables.

Terminology

This terminology is what the Japanese use: most is in Japanese, but several Chinese pronunciations are still kept.
The shorthand (A, P, C) is my own, feel free to use whatever fits your mind.
Thanks to John Mackin for editing this and creating a table (rather than the ugly pre-structure I had here before :)

TILES (pai/hai- tile)
Sangenpai - dragons (Haku - blank, Hatsu - begin/go out, Chum - middle) 
Kaze - winds (Ton - East, Nan - South, Sha - West, Pei - North) 
dora - special tile ($) 

HAND STATUS (yaku - hand)
Jihai - letters
   A - winds & dragons
   P - Pon, 3 of the same tile, getting the third from another player.
   C - Chi, 3 tiles in numeric sequence, getting the third from the player on your left.
Ron - complete yaku; win
Kan - 4 tile wall
Richi - -P, -C, 1 tile to win(1k ante)
menzen - -P, -C (like richi) 
Ippatsu - Ron within 1 turn of richi (can pick yourself). Unless someone P or C your discard tile. 
naku - P or C 
Daburi - get Richi on first turn (+1)
haite/hote - win with the last tile (+1 yaku); haite if you pick yourself, or hote
kyoku - counting hands 
flush - same suit 
3's - 3 of a kind 
tenpai - 1 to finish 
noten - no chance to win 

RULE SETS
Ari-Ari - rule set (="exists")
Nashi-Nashi - rule set (="does not exist")

PLAY STATUS
tapai - too many tiles 
nakenai - negate 
shopai - not enough 
Ryu-Kyo-Ku - no winner
han chan - 2 direction round 
tomato - 2 identical tiles in discard, separated by 1 tile
shinbunshi - like tomato, but 5 tiles
chombo - When you make a mistake that breaks the rules. Usually you end up paying 8k 
maneman - discard same tile as prior player
Furiten - Can't have a tile in your discard pile that can finish hand.
The only thing to do is change your hand, or pick it yourself
Yakitori - If you don't win any hands in 2 rounds, 8k penalty, unless
you are dealer on last hand, then 12k penalty.

Starting the Game

Everyone gets 30,000 points, usually in the following breakdown: 1 10K, 2 5K, 9 1K, and 10 100's.
First, arrange 1 of each kaze, and 1 odd tile, and 1 even tile. Place them face down and mix them.
To start the game, the winner of the last game rolls the dice (or just pick someone :). Counting counter-clockwise, starting from whoever rolled, go to number on the dice. This determines where East is.
The person sitting there rolls the dice. Flip the tiles over, move numbers to opposite ends, depending which end they are close to. From the odd or even end, depending on the number rolled, deal the tiles out counter-clockwise from the number/position rolled. These are your positions. Move to new position based on where East is. All of this was simply to determine who sits where.
To determine who is dealer, the current East rolls. The next person rolls. This roll decides who is the dealer, ie the new East.
You can mix all the tiles before or after figuring this out. Mixing the tiles involves placing them all face down and shoving both hands towards the center of the table, while grinning like a madman listening to all the clattering of tiles, since everyone else is doing the same thing. Try not to shove so forcefully that tiles go flying off the table. If some tiles should happen to flip over, don't worry, just flip them back and continue shuffling a bit. Once you have played a little, you will realize that the sound of tiles being shuffled is one of the most hypnotic, addictive noises .. you will recognize it through walls, out on the street .. it is the Mah Jong call of the wild. All right, enough poetry .. :-)
Oh yeah, once the tiles are mixed and everyone has had enough fun, usually one person who is in a hurry to a)win money b) lose money will start building his wall. Each player should build a wall in front of them 2 tiles high, stacked next to each other. This would come out to about 17 tiles long, but usually one person builds faster than someone else, so the walls aren't necessarily the same length. Don't worry about it.
Now you are ready to start the first hand (this part gets repeated for each hand during the rest of the set, until you change seating positions -- if you do); the dealer (East) rolls the dice: the number rolled determines which player's wall we start picking from, and where on the wall we start. Count number rolled from the right end, and separate the wall at that point. Flip the top tile 3 tiles from the left (from center of table) of the new break in the wall. This is how the dora (wild) is determined. It is the next tile in whatever sequence the flipped tile is in. If in a suit, the next number, wrapping from 9 to 1. If a kaze, the next wind, wrapping from North to East, and if a sangenpai, wrapping from Chum to Haku. The dead wall consists of the seven pairs of tiles before the break (this includes the dora). There must always be 14 tiles in the dead wall, so any removed because of kans must be replaced by going backwards further in the wall. If the original wall runs out, you absorb some from the right end of the wall to the left (again from the center of the table).
Next, you pick your initial hand out of the wall, to the right of the break you made in the wall. East picks 4, then South .... You pick 4 tiles, 4 more, 4 more, then 1. When you're making your hand, you (usually) need 4 sets of 3 tiles and a pair, a total of 14, which includes a tile you draw.

The Deal

A quick description of the deal: the game is divided into 2 or 4 rounds, depending on how long you are going to play and how patient everyone is. Each round has a 'prevailing' wind. The first round starts with East, the next round is South. If you are playing a 4 round game (which my friends don't like to do, because usually after 2 rounds someone is broke), then the 3rd and 4th rounds would be West and North.
Each round lasts until each person has been the dealer and lost the deal. The shortest a round can be is 4 hands (one for each player). A hand is one playing session until someone gets a yaku and wins, or you run out of tiles in the wall and the hand ends. At this point you calculate if the hand is tenpai or noten (winning or losing). See below, if you are noten, you have to pay into the pot, whoever wins next will win the pot as well as payment for their hand.
Here are a couple more rules related to the deal: 

If you are in East round and you are noten, you lose the deal. If in
  South round, keep deal.
If everyone richi's, hand is over.
If everyone discards the same first tile, hand is over.
If you have more than 9 different 1's, 9's and A's, can restart.
For every hand dealer keeps, must place 100 up on table.  Each hand
  is worth 300 more than previous hand (3rd hand has 200 up, worth
  600 more) for whoever wins, not just dealer.  If dealer is noten,
  and has 100+ up, either he (South rnd.) or next dealer (East) adds
  100.
Ryan Shi - if dealer keeps the deal 5 times, everyone must have 2 or
  more yaku to win a hand.
Pa Ren Chan - If dealer wins 7 times, gets yaku man for 8th win.
Nagashi Mangan (8k) - If there are only 1's, 9's and A's in your
  discard, you actually have a yaku at the end of the hand.  No one 
  can have pon'd or chi'd any of your discard tiles either.
Opun Richi - Show hand, leave open, when you richi.  Everyone knows
  what you have!  Only useful if someone else has richi'd; they must
  discard tiles which don't win their hand.  +2 yaku if you pick
  winning tile, Yaku Man if someone tossed what you need!

3 Player Mah Jong

If you find yourself in the sad position that there are only 3 of you around, you may try to play without a 4th (yes, addiction isn't pretty :) There are two methods, I prefer the first: Make four walls, and remove one of them from play. This gets rid of a random quarter of the tiles. The second way is to manually remove one whole suit, but I think this unbalances the game too much. Either way, at least you can play, and that's what an addiction is all about :) We split the payments in thirds instead of quarters, so if the dealer would normally pay half to a winner, he pays 2/3 (twice as much as the other player).

Ron Rules

Just a couple rules about going out. First, we have already described furiten above. Also, if you are waiting for tiles, if you pass up a winning tile (you greedy person, you) then you cannot Ron on another winning tile discarded by someone. You must tsumo , meaning pick the tile yourself. 

Rin Shan Kai Ho - if you kan, then ron on extra picked tile, +1 yaku
Chan Kan - if you can Ron on a tile someone just kan'd, +1 yaku

Yaku

I will also discuss rule sets here. First, the basic, easy yaku that can be combined with anything. Format:
(1)		Tsumo - pick last yourself		-P,-C
		Need luck to pick last tile	"Menzenchin"
On the first line, we have the number of yaku for a hand, the name commonly used for it (slang), and a short witty description by yours truly. On the right are any restrictions. A stands for sangenpai and winds, therefore -A means 'not' A, or no sangenpai or winds. A tilde (~) will mean that it can be used, but there are restrictions or you lose points. In almost all cases, if you Pon or Chi, you will lose some points. The next line continues the description, or sometimes has an example. Also, at the end of the line in double quotes ", there is the official name of the hand.

(1)		Richi (Men) - pick or Ron last tile.	-P,-C
		Any 4 straights or 3's, 1 pair.  Extra dora, dora of
		tile under current dora.
		Note: if you richi, and some one goes out on your discard,
		you don't lose your 1k ante.
		+1 yaku if you Ron within 1 turn.


(1)		Pinfu - 1 pair, 4 straights		~A,-P,-C
		Waiting for straight, with 2 available winning tiles.
		Can't use important Kaze for pair, no sangenpai


(1)		Tanyao - No 1's, 9's, or A		-A,-P,-C
		4 straights or 3's, 1 pair	"Tanyaochu"

Rule Sets

The above yaku are very basic and will usually be involved in any hand one gets. The two rule sets that I have used are Nashi-Nashi and Ari-Ari. The yaku here are written for Nashi-Nashi, the more difficult rule set. In Ari-Ari, there are 2 other neoyaku: Kinke Doku Ritsu - 4 Pon or Chi groups, and Ron on a pair; and Ato Zuke - let's you Pon or Chi anything.
These combine to allow you to complete Tanyao (above) with P or C. This modified Tanyao is called Kuitan. The yaku group of Kinke Doku Ritsu, Ato Zuke, and Kuitan, make up the Ari-Ari rule set, which is just a modification of the original, more difficult Nashi-Nashi set.
On with the yaku:

(1)		Ipeiko - 2 identical straights		-P,-C



(2)		Chan ta - Every combination must	~P,~C
 or (1)		include 1's, 9's, or A		"Chan tai yao"


(2)		San Shiki Dojun - same straight,	~P,~C
 or (1)		3 suits			"San shiki ton shun"


(2)		Ittsu - Straight flush, 1-9		~P,~C
 or (1)						"Ikkitsukan"


(1)		Hon Pai - 3 of your direction(s) or
		or sangenpai.  (2) for unique direction: Ren Fon Pai.
		Must do Sangenpai first or last (for Nashi-Nashi) 


(2)		Toi Toi - 4 3's 1 pair
		May Pon.  See Su An Ko (-P)	"Toi Toi Ho"


(3)		Hon Itsu - flush, 3's or straight's
 or (2)		A, P, and C allowed


(3)		Jun Chan - All containing 1's, 9's	-A
 or (2)		No letters (see Chan ta)


(2)		San an ko - 3 3's.  Can't Pon or Ron	-P
		for any 3's.  Can Chi for straight.  Better to
		Ron on straight.


(2)		San Kan tsu - 3 walls (kan)



(2)		San Ren ko - 3 identical straights or
 or (1)		3's.  Can kan a pon.  Count by 3's, scores
		higher.


(3)		San Shiki doko - 3 same 3's, different
		colors. (See San shiki dojun - straights)


(1)		Chi Toi Tsu - 7 pairs			-P,-C
 =50 pts	Niko-Niko.  Can't have 2 identical pairs.


(2)		Ren Fon Pai - Hon Pai on kaze that is your
		unique direction.  East: ton-ton


(2)		Sho San Gen - 2 sangenpai 3's, 1 pair of
		sangenpai.  Pon and Chi are allowed.


(2)		Hon Ro To - 4 3's of 1's, 9's, or A, and
		a pair of 1, 9, or A


(3)		Ryan Peiko - 2 pairs of identical straights (4)
 or (2)		(harder version of Ipeiko)


(6)		Chin Itsu - flush, no A			~P,~C
 or (5)		Cheaper version, Hon Itsu, includes A

Yaku Man

These are still yaku, but all of these are big point ones, called Yaku Man. These all must include specials, or are very difficult to complete.
Here they are:

32,000		Dai San Gen - 3 3's of sangenpai.  Can
		finish with normal tiles.  *


32,000		Sho Su Shi - 3 3's of Kaze and a pair of
		Kaze.  This means you have all 4 Kaze :-)  *


48,000		Dai Su Shi - 4 3's of Kaze  *
		*pow!*

Note: If whoever gets the * hands pons all 3's, whoever discarded last pon'd tile pays winner (ouch!).

32,000		Su Kan Tsu - 4 kans, any pair



32,000		Tsu I So - All A



32,000		Chin Ro To - All 1's, 9's



32,000		Ryu I So - All Green.  Hatsu, and from
		Bamboo's: 2-4,6,8  (This is an American hand :-)


32,000		Su An Ko - 4 3's.  Must pick all 4 3's	-P,-C
		tanki - x2 if Ron or pick pair.  Only 32k if
		pick last 3.


32,000		Dai Sha Rin - 7 pairs, flush, in order
		*pow!*


32,000		Koku Shi Muso - 1 of each A, and 1's and 9's
		in 3 suits, plus one more of those 13 (to make
		14 tile hand)


48,000		Chu Ren Poto - 3 1's, 3 9's, straight flush   -P, -C
		1 through 9, 1 pair in between (to make 14 tile hand)
		This is the Double Jackpot :-)


32,000		Shi San Puta - Nothing good.  This is good!
		Can't have any tile that could possible make
		straight (4 and 6 is a possible straight), and
		must have exactly 1 pair.
		Note:  if dealer, from tiles dealt, if not dealer,
		call after first tile drawn.


32,000		Ten Ho - have a complete hand dealt to you.
		(4 groups of 3, 1 pair)


32,000		Chi Ho - Complete hand within 1 tile after deal.


32,000		Miyakono Seihoku* - 3 3's,3 8's,3 5's,3 W,3 N, miss 1 tile.
		(Waseda Yakuman) this hand seems VERY minor though.
*Miyakono Seihoku means northwest of the capital (where Waseda Univ. is
located at) -hand donated by Tak (Waseda alum?)


32,000		SouthEast Special* - 2 each of N,S,E,W, and 1 3/straight
		& pair (for normal total).  Extra if meaningful DC street
		address is in remaining tiles (ex 1600, 724, 1260)
*Washington, D.C. local hand, created by me :)

Scoring

A couple scoring tips. First add the number of yaku. Then, depending how you went out, you may have a few extra points (See "Going Out Points"). Next, your groups of 3 of a kind are each worth something (straights are worthless). Look at "Points for Tiles" to determine how many points you get for 3's, as well as your pair if you Ron'd on it.
Add all these extra points, then consult the handy-dandy point/yaku table below to see what the final score is.

Again, a couple rules: 

Sha Nyu - if no one scores over 33,300 after 2 rounds, must play
  another round.
If you didn't Pon or Chi from another player, and you Ron from
  another player, start from 30 pts rather than 20.

Wei-Hwa's site on Toudai-Shiki scoring, Scoring in Japanese Mah Jong [same site linked at top of doc] has an explanation on how the values in the table actually came to be (it involves powers of 2):
For example, say you have 38 base points (what I call "abcissa")                
and three fan (what I call "exponentials").                                   
                                                                        
Then your hand's score is calculated like this:                         
  Round 38 up to the nearest 10 = 40.                                    
  Add two to the number of fan = 5.                                             
  Calculate 40 times 2 times 2 times 2 times 2 times 2 (5 times) = 1280.        
This is how much each player should pay you.  If one of the payers is   
dealer, then the payoff is double.  Therefore, if you're                
dealer, then everyone pays 2560; if not, you'll get 1280 from               
two players and 2560 from the dealer.                                   
                                                                        
Except that we don't have points in units of 10, so round up to 1300 and        
2600.

Going Out Points
How you went out
\
Waiting for ..
 Tsumo Ron
Yan Men - 2,3
2 tiles in straight 		2 0
Kan Chan - 1,3
1 between 		4 2
Pen Chan - 1,2
1 at end 		4 2
Tan Ki - only 1 kind
of tile (pair) 		4 2
Sha Bo - 2 pairs
waiting for either 		2 0

Points for Tiles
Type of tile
\
Tile groupings
 Not 1,9, or A 1,9, or A
Ko Tsu -
3 of a kind 		Open 2 4
Closed 4 8
Kan Tsu -
4 of a kind 		Open 8 16
Closed 16 32
Toi Tsu -
pair 		1,9, no impor-
tant kaze 		0
Important kaze,
sangenpai 		2
Ren Fon Pai -
x2 kaze 		4

Points/Yaku Score Conversion
(First number is for non-dealer, 2nd for dealer)
Yaku
\
Points
 1 2 3 4
20
 1000
1500 		1300
2000 		2600
3900 		5200
7700
30 1000
1500 		2000
2900 		3900
5800 		7700
11600
40 1300
2000 		2600
3900 		5200
7700 		5 yaku
50 1600
2400 		3200
4800 		6400
9600
60 2000
2900 		3900
5800 		7700
11600
70 2300
3400 		4500
6800 		5 yaku
80 2600
4400 		5200
8700

For 5 yaku and up, there is a flat rate:

Yaku	Money	Name
5	8K	mangan
6,7	12K	haneman
8,9,10	16K	bai man (double)
11,12	24K	sanbaiman (triple)
13+	32K	YakuMan
Also, remember that if the dealer wins, he gets 50% more, but if someone else wins by themselves, he pays 50% of loss, instead of 33%. If dealer loses directly to winner, just pays normal.
I hope you can use this page somewhat to aid in your quest to master Mah Jong.
In Aug. 1997 this page was getting approx. 1,000 hits a month, which was fairly respectable. Mar. 2001: up to 3,000 a month. Mar 2003: almost 6,000 hits/mo. Aug 2004: back down to 3,000/mo (page no longer maintained).

Have a nice day!! Last edit: Fri Sep 3 2004
Add EOL notice at top, links to other sites.


Laurent Delfosse