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FAQ #20. Commonly Misunderstood Rules of Asian Forms of Mah-Jongg

Including Western (British/Australian) rules, Hong Kong rules, Taiwanese, Shanghai rules, Chinese Classical, CMCR, Japanese, etc.

Sets of tiles concealed within your hand are your "happy secret." Mahjong isn't Rummy - the goal isn't to get rid of the tiles in your hand, it's to build a complete hand (hopefully without letting on to other players how complete your hand is). While you have to expose a completed set when taking a discard, you do not have to expose a complete set that's concealed in the hand. If you have a complete chow or pung in your hand, you don't WANT to expose it for all to see. So when you have a complete chow or pung in your hand, keep it hidden in your hand as your happy secret.

Calling a discard for exposure. You can take a discard to make a chow only when it is thrown by the player at your left. That means it's your turn, and you can start your turn by taking the discard.
BUT... To make a pung or kong, or to declare mah-jongg, you can take anyone's discard (even when it isn't your turn).

Winning on a discard. When you are ready for mah-jongg, you can win by discard no matter what the tile is used for (chow, pair, pung, single). That portion of the set completed by that tile might have to be scored lower, but the win is valid (even if the hand is supposed to be concealed, unless the hand specifically must be won by self-pick).

Punging restarts the order of play. When someone other than next-in-line after the discarder claims a discard to make a pung, the regular order of play is interrupted. Let's say Player A discards. It's Player B's turn next... unless Player C or Player D calls "pung." After the punger has discarded, play order resumes from the punger (not from the discarder of the punged tile).

A kong is a special "exalted" pung. But it's still a pung for tile count reasons. You can think of the kong as a pung wearing a fourth tile on its head like a crown. Although you see four tiles, it's still considered a pung. Sort of. The typical hand is "four groups and a pair" - fourteen tiles in all. A "group" is usually "three tiles." So when a group is a kong (four tiles), then it messes up the tile count. ." Four groups and a pair is fifteen tiles if one group is four tiles instead of three. If your hand has four groups, and one of the groups is four tiles, say because you just picked a fourth from the wall and exposed a kong, you don't have a tile to discard because now you have "four groups and a single." With me so far? So to preserve the hand's integrity, a replacement tile must be taken from the back end of the wall, just as is done with flowers (unless your rulebook defines a "kong box" separate from the "flower wall").

This is a kong - four of a kind. All four of a single tile = "kong." It counts as a special sort of pung.

- When you have four identical tiles concealed within the hand, you have the option of melding them, declaring the four to be a kong that counts as concealed, so you can take a replacement tile. Different rulesets have different norms for how a concealed kong is to be displayed (all face-down, or the two end tiles face-down, for instance).
- When you have three identical tiles concealed within the hand, and an opponent discards the fourth, you may claim it (the same as you would pung a discard) and expose the completed kong.
- When you have an exposed pung and you pick the fourth tile from the wall, you have the option of promoting your exposed pung to an exposed kong. (You may not take the discard to add to your exposed pung.)
In all cases of kong declaration, a replacement must be taken from the back end of the wall.


An easy-to-read intro for beginners and an excellent reference for expert players, The Red Dragon & The West Wind is a complete guide to official Chinese and American mah-jongg. Look for it on Amazon or Barnes & Noble. Available in print or electronic editions. You'll also want to download the errata for latest updated info.

Speaking of flowers... Flowers don't count as part of the hand's tile count. When counting your tiles (either to see if you need to pick or to discard, or to check if your hand is dead or not), count only your exposed groupings and your concealed tiles - don't count the flowers. And if you have a kong (a pung with a bonus fourth tile), count that as three tiles (not four).

Can I make a 3456 chow, four numbers instead of the usual three? No, you cannot. A chow is "three consecutive numbers in a row," end of story. A four-number sequence pattern is very useful strategically (in building the hand), but it's not an exposable set, and there's no place for those four tiles in a complete four-sets-and-a-pair hand.

You cannot do this in a finished mahjong hand. This is not a chow, and it is not a kong.
Three in a row = "chow." Four of a kind = "kong." There is no such thing as a run of four in any form of mah-jongg.
Rummy, yes. Mah-Jongg, no. But this combination is powerful in the early phase of a hand, the building phase.

Can I chow ESW or ESWN or WGR? No, you cannot make a chow from three different dragons or three different winds or three consecutively numbered flowers. There is no such thing. A chow is made from numbered suit tiles only. Three of them.

Conflicting claims for exposure. When one player claims a discard for chow, and one claims it for a pung, then the pung call overrides the chow call.

Conflicting claims, one for exposure and one for the win. When one player claims a discard for exposure, and one claims it for mah-jongg, the player who needs it for mah-jongg takes priority.

Conflicting claims for mah-jongg. When two players claim a tile for mah-jongg, as long as both claims were spoken within a reasonably short period of time, the player whose turn would be next in order of play (counterclockwise from discarder) is the one who gets the tile. It's not a race; the player who verbalized the claim first does not necessarily get the tile. There are exceptions to every rule: Some forms of mah-jongg (such as Japanese) allow both players to win. And some forms (such as HKOS) may allow a claim for a high-scoring hand or special hand to take precedence over another winner's claim.

Seat winds in Chinese mah-jongg are not like a map. Going counterclockwise around the table, players' winds are East, South, West, North.

In Chinese mah-jongg, seat winds do not correspond to the expected compass directions on a map (East, North, West, South) as if looking down on the table from the heavens. They were never intended to!

Exposed vs. Concealed.
Q: I know that some hands are permitted to be exposed and some must be concealed, but what do the terms "exposed" and "concealed" mean exactly?
A: Concealed means "all concealed, win by discard permitted." And Exposed means "there is at least one exposure (meld)."
So, if a player is displaying one or more melded exposures, which kind of hand is the player holding...? Exposed. If a player says mah-jongg without having previously melded any exposures, which kind of hand did the player have...? Concealed.

No player may ever take a discard and put it into the concealed hand. The price for taking a discard is that you must complete a set with it, and you must expose that completed set (without ever putting that taken discard into the concealed portion of your hand).

Only the most recent discard is available for taking (and only while the Window Of Opportunity is still open). Once another player has picked a tile from the wall and used it, that "old" discard is considered "covered" by the new discard. In card games, when one discards a card, one places it on a pile, right? Well, we can't do that with mah-jongg tiles because the tiles are so thick -- the increasingly tall stack of tiles would quickly become unstable and fall over. In forms of mah-jongg in which discards are simply placed randomly on the discard floor, a player has to simply keep an eye on the table and know which discard is the most recent one.

The Window Of Opportunity to claim a discard.
Q: If the next player has already picked a tile from the wall and someone else wants to claim the most recent discard, does the player have to put the tile back on the wall?
A: In Asian variants, it depends on how much time has passed. Let's say Player A discards. Player B starts their turn, but Player C says "pung." If Player B has picked from the wall (even if it has been seen or put into the hand) but Player C's claim is spoken within 3 seconds from the time the tile was discarded, then Player B needs to put it back and allow Player C's call to be fulfilled.
But if more than 3 seconds have passed since the tile was discarded, then the call is deemed to be too late.
Note: The 3-second rule is the official rule in Majiang Competition Rules. 3 seconds is a reasonable window in other Asian forms* of mah-jongg as well. For more on the Window Of Opportunity, scroll down.
* The 3-second rule does not apply to American/NMJL rules.

A wall tile was seen; now what? Or sometiles were knocked off the wall; now what? When a wall tile is accidentally exposed, it's just too darn bad, but it goes right back where it was. Once the wall is built, whenever something happens to the wall, best efforts must be made to preserve the original order of tiles in the wall, regardless of how much information was revealed to any players.

Why are there numbers on the flowers?
The numbers correspond to seat positions of the players. East is seat 1; South is 2; West is 3; North is 4. If you use flowers (I didn't want to go into flowers because they add a complexity to the rules), then your score is doubled if you have a flower with your seat number on it. Your seat number changes as the deal moves around the table, so you have to keep track of your position relative to the current East. Not all Asian variants use the flower tiles. There are no flowers in Japanese riichi/dora majan. Hong Kong players usually leave the flowers out of play.

Is it "die" or "dice"? "Dice" is the plural of "die." In mah-jongg we don't roll just one die, we roll two dice - or more than two, depending on the variant you're playing.

What is the rule when somebody wants to claim a discarded tile for exposure after the next person has already picked a tile from the wall?

Your question is about what I call the "window of opportunity" rule. The "window of opportunity" is that brief moment in time during which a player may claim a discard. When does the window of opportunity open, and when does it close? NOTE: Most rulebooks of Asian forms of mah-jongg do not include this level of detail. Thus the principle described below, adapted somewhat from American mah-jongg, is not enforceable if the players have a different way of doing things. American mah-jongg and Chinese Majiang Competition Rules have detailed written rules, but many forms do not. That said, the following is still good food for thought, for players of all variants. - Tom

Opening the Window of Opportunity
The window opens the instant a discarded tile is either named (if your group announces tiles when discarding) or it touches the table top, whichever happens first. The tile is now "down," and is available for claiming by another player. (And the discarder can no longer change his mind and take it back.)

Next Player Picks From the Wall
The next player (the player to the right of the discarder) now reaches (ideally allowing other players a reasonable moment in which to claim the live discard), takes the next tile from the end of the wall, and looks at it. He cannot change his mind and put the tile back, but the window of opportunity is still open on the most recent discard. His taking and looking at the picked tile did NOT close the window of opportunity on the live discard - anybody can still call it!

Closing the Window of Opportunity
Any other player can claim the current discard right up until one of the following events occurs:
      The current player puts the picked tile among the other concealed tiles in his hand;
      Three seconds have passed since the tile was discarded;
      The current player discards his picked tile;
      The current player declares mah-jongg with his newly picked tile.
Once any of the above has occurred, the window of opportunity CLOSES on the discarded tile we've been discussing. It's now too late for another player to claim that tile for exposure or for mah-jongg.

One Window Closes, Another Window Opens
When a player picks and discards, that old discarded tile is now "dead," and is considered "covered" by the new discarded tile.

I recommend that all tables have a copy of a good rulebook. See FAQ 3 for a list of books on numerous types of mah-jongg, and see FAQ 2b if you need to identify which type you play.

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An easy-to-read intro for beginners and an excellent reference for expert players, The Red Dragon & The West Wind is a complete guide to official Chinese and American mah-jongg. Look for it on Amazon or Barnes & Noble. Available in print or electronic editions. You'll also want to download the errata for latest updated info.

© 2004-2024 Tom Sloper. All rights reserved. May not be re-published without written permission of the author.