Nobody plays exactly the same game. The official rules cover how to play a hand, not the dozen small questions a Tuesday table runs into by nine o'clock. Here is what is worth settling out loud, and what the named variations actually mean.
Get the free score sheet It has a row at the top to write your rules in.
The National Mah Jongg League publishes a new card every April, with rules that are thorough about anything that decides a hand: how many tiles you hold, what you may call, when a hand is dead, what the winner is paid. Tournaments and online play follow them to the letter.
A house rule, also called a table rule, is anything your own group decided instead of the official answer.
How it works
Already know these? Skip straight to the checklist below.
The stack of face-down tiles each player draws from during play. When it runs out with no winner, that's called a wall game: nobody scores, and you deal again.
The winds (North, East, South, West) and dragons (Red, Green, White), as opposed to the numbered suit tiles (bams, cracks, dots).
Three mandatory rounds of passing tiles before play begins, required by the official rules. Some tables add an optional fourth pass, the courtesy pass, see the vocabulary section below.
A hand turns exposed once you've called a tile from another player and set it face up on the table. It stays concealed if every tile came from your own draws, which pays more on most hands.
A wild tile that can stand in for almost any tile on most hands, except in the singles and pairs section of the card, where jokers aren't allowed at all.
Most of these take ten seconds to agree on and save an argument later. Where the official rules already have an answer, it is noted. The app's casual mode doesn't always match that official math exactly, though, some of these are flatter, simpler approximations on purpose.
Play the app's official NMJL scoring mode instead, and most of these aren't decisions at all, just how the card scores every hand.
The official rules are written around players paying each other, usually in coins or chips. Many casual groups skip that entirely and keep points only.
Worth saying out loud because it changes everything below it. If nothing is being paid, the point values are just a way of keeping score, and you can pick round numbers that are easy to add.
Officially the value printed next to that hand on the current year's card, which changes depending on which hand you win.
In the app's casual mode it's one flat number for every win, set once and used all season, often 2 points. Decide whether each point is worth actual money as you play, or whether points are just for keeping score with a pot at the end.
Want the card's real values instead, changing hand to hand? That's what the app's official NMJL scoring mode is built for, you type in each hand's printed value as you log it.
Officially yes. The discarder gives the winner double points, while the other two give the winner the hand's face value.
For house rules, "paying" isn't really the point when there's often no money on the table. Three common ways to play it:
In the app's casual mode all three are yours to pick, right in the rules setup: points vanish, points move to the winner, or no penalty at all.
Officially all three players give the winner double points when the winner draws the tile from the wall rather than taking a discard.
In the app's casual mode that version isn't an option, a flat bonus is the only one available, worth one extra point by default. The decision for your table is simply whether to turn it on or off.
Officially a jokerless hand outside the singles and pairs section pays double, and four times the value if it was also self picked.
In the app's casual mode a flat bonus is the only option here too, one extra point by default. Two decisions for your table: turn it on or off, and if it's on, whether a singles and pairs hand still counts, since it never uses jokers in the first place and reasonable people disagree about that one.
The app already tracks a nightly winner and season standings at the same time, automatically, so this isn't really a night-or-season choice. What's worth settling is the season's length: a month, a few months, the whole year.
We recommend keeping both. A nightly winner gives every night its own small win, and the season total gives the whole thing some stakes.
None of these are National Mah Jongg League rules, and none of them have one settled definition. New to the game? Skip all of them for now, play with no special wall status and a plain Charleston, and come back once you're curious. If a new table says they play one, ask which version.
Once play reaches the final wall, no discard may be called for any reason. The hand finishes on draws alone unless somebody is already set.
Some groups add a penalty on top: a player who discards the winning tile during the hot wall pays for the whole table.
Ask: does the penalty version apply, and where exactly does the last wall start?
The gentler sibling. During the final wall you may still call a discard, but only to declare mahjong. You cannot call one to make an exposure.
Ask: hot or cold, because the two names get swapped often enough that hearing one is not the same as knowing which you are playing.
An extra hand that is not on the card: seven pairs. Groups that play it generally require you to declare it before the first Charleston pass and turn your card face down, and bar jokers and flowers from the hand. Four of a kind counts as two pairs.
It is contentious. Plenty of experienced players will not play it, on the grounds that it changes what the game is.
Ask: what does it pay, and what happens if you pick up a joker after declaring?
An optional fourth pass in the Charleston, usually one to three tiles, agreed on before the hand starts.
Not in the official rules and not something the app sets, purely a table call. Skip it and pass three times only if your table would rather.
Ask: is a fourth pass happening tonight, and how many tiles?
This one has two meanings in circulation, which is exactly why it belongs on a page like this.
In one, at the end of the first Charleston everyone puts their unwanted tiles face down in the middle, they get mixed together, and each player draws back as many as they put in.
In the other, mush is simply another name for the courtesy pass across the table.
Ask which one, every time.
The name comes up on lists of common table rules, and we still do not have one clean definition of how it is scored or played. Tom Sloper, whose column is cited below, wrote in to say the same rule also goes by "Picking ahead," "Playing with a future tile," and "Playing with fourteen tiles," which points toward some kind of tile held or drawn ahead of your normal turn. That is a real lead, not a full definition, so we are still not going to guess at the mechanics.
If your table plays it, under any of these names, we would like to know how. See the note below.
The official positions above come from the National Mah Jongg League rules as they are commonly documented. The descriptions of hot and cold wall follow Tom Sloper's long running mahjong column, which is the closest thing this game has to a reference desk, and he is also the source for the alternate names for Throw and pick above. Atomic is described as the groups who play it describe it.
Beyond that, the honest answer is that American mahjong house rules are an oral tradition. They travel by table, not by book, and the same name means different things two towns apart. If your group plays something worth writing down, send it to hello@themahjreport.com and we will add it, with credit to your table if you want it.
The free printable score sheet has a row across the top for exactly this: what a mahjong pays, what each bonus pays, settled once at the start of the night instead of relitigated every hand. Print a stack and keep them with the tiles.
Get the score sheetThe Mahj Report is a scoring app for casual American mahjong. Set what a mahjong pays and what each bonus pays, or switch to official NMJL scoring and use the League card's own values. It keeps the running total, crowns a winner every game night, and settles the season title. Not affiliated with the National Mah Jongg League.
Download on the App Store