American mahjong rules: the official line and the house variations

The set and the deal

A standard set has 152 tiles: three suits of 1 through 9 (four copies each), four of each wind, four of each dragon, eight flowers and eight jokers.

Each player builds a wall 19 tiles long and 2 high. Everyone takes four tiles at a time for three rounds, then East, the dealer, takes two more (the first and third top tiles) and the others one each: East holds 14, everyone else 13. East discards first. Play passes to the right; walls push out to the left.

The Charleston

1. 1Right
2. 2Across
3. 3Left

The Charleston is the passing of tiles between the deal and the first discard. The first Charleston is required: three tiles to your right, three across, three to your left, exactly three each time, and once a round starts it must finish. Any player may stop things after those three compulsory passes, no reason required. If nobody stops it, the second Charleston mirrors the first: left, across, right.

Afterward you and the player opposite may trade up to three tiles in the courtesy pass. If your numbers differ, the smaller one rules.

Blind passes are legal on exactly two passes, the first left (the last pass of the first Charleston) and the last right (the final pass of the second): take one to three tiles from the pass coming to you, unseen, and send them on, topping up from your rack. Jokers never travel in any pass, blind or courtesy included.

At some tables, casual groups allow passing jokers or skip the Charleston entirely for speed. That’s fun at home and illegal everywhere else.

Turns and the claim window

On your turn, draw one tile from the wall and discard one face up, naming it out loud. A discard stays claimable until the next player racks their drawn tile (places it on their rack), discards, or begins a joker exchange. Picking a tile up and looking at it does not close the window; racking it does. In a dead heat between a call and a rack, the caller wins and the picked tile goes back to the wall. All older discards are dead.

A misnamed discard cannot be claimed until it is named correctly, and the discarder must rename it, not take it back. If someone declares mahjong on the wrong name, the misnamer alone pays four times the hand’s value.

At some tables, especially beginner tables, play pauses before racking so newer players get a fair look at each discard. Standard play does not wait: you rack the tile you picked and do your thinking afterward.

Calling discards

You may claim a discard only to win or to complete a pung, kong or quint (three, four or five identical tiles), which immediately goes face up on your rack as an exposure. Pairs and singles can never be called, with one exception: any tile that completes your mahjong may be claimed, even for a pair.

Jokers can fill any or all of the called group’s other tiles; no natural tile is required. When two players want the same discard, mahjong beats an exposure no matter who spoke first. Two mahjong claims go to the player nearest in turn after the discarder.

Jokers

Jokers stand in only within groups of three or more identical tiles: pungs, kongs, quints. They never go in pairs or as singles, and never inside a year like 2026 or the NEWS winds. A discarded joker is dead and cannot be claimed by anyone.

The exchange: on your own turn, after your 14th tile is in hand and before you discard, you may swap a natural tile for the joker it represents in any exposure on the table, including your own rack’s. The exchange cannot be refused, and there is no limit per turn. If it completes your hand, the win pays as self-picked, the same as drawing your winning tile from the wall.

At some tables you will hear that a call needs at least one natural tile, or that a player can decline your exchange. Both are myths, though plenty of experienced players still teach them.

Concealed hands

Lines marked C on the card, for concealed, must be built entirely from the wall. You make no calls and no exposures, with one exception: the winning 14th tile may be claimed from any discard. Joker exchanges are still allowed along the way.

Dead hands

A hand goes dead when it holds the wrong number of tiles, makes an exposure that matches no line on the card, can no longer match any line given its exposures, or has its concealed tiles improperly revealed.

You cannot declare your own hand dead; another player must call it, judging only by what’s visible. A dead player stops picking and discarding but stays seated and still pays the winner, and jokers in their valid exposures remain exchangeable. A wrong dead call costs the challenger.

At some tables, social groups never call hands dead at all and just play on. That’s kinder and slower, and fine as long as everyone knows it’s a house choice.

Scoring and payments

The card prices every hand. Win off a discard and the thrower pays double the value while the other two pay face value. Win from the wall (a self-pick), or complete your hand through a joker exchange, and everyone pays double. A jokerless hand doubles its value first (except a singles and pairs hand, which can never hold a joker), and the doubles stack: a jokerless self-pick collects four times the printed value from each player.

A wall game, when the tiles run out with no winner, pays nothing. Reshuffle, and the deal moves right.

At some tables, quarters games ante into a pot on wall games for the next winner, and some make a player who feeds an opponent with three exposures pay for the whole table. Points across games are a tournament thing; most home tables just count wins.

The famous house rules

Two famous ones live outside the rulebook entirely. Blanks are spare tiles that some sets ship with, played as swappable wilds: a blank trades for any tile in the discards. Southern tables love them and traditionalists loathe them, and they are never legal under National Mah Jongg League rules.

The bettor is a fifth player who may wager on one of the four hands before the Charleston and win or lose with it. It’s an official league option most tables have never used.