This is the one-page reference. Each section gives you the rule itself, short and exact, and links to the longer guide if you want the reasoning and the edge cases. It follows the National Mah Jongg League's four-player game as played at clubs and kitchen tables across the US. We teach the structure of the game; the current year's card you buy from the League.
Players, tiles, and the goal
Four players. A full American set has 152 tiles: three suits (craks, bams, dots) numbered one to nine with four of each, four each of the four winds, four each of the three dragons, eight flowers, and eight jokers. The goal is to be first to assemble fourteen tiles that exactly match one of the hands printed on the current year's card.
Setup and the deal
Tiles are shuffled face down, and each player builds a wall nineteen tiles long and two high in front of their rack. East rolls the dice to decide where the wall is broken. Dealing goes in blocks of four to each player three times, then one more tile each, so everyone holds thirteen and East holds fourteen. East does not discard yet; the Charleston comes first.
The Charleston
Before play, players pass tiles in a fixed sequence: three to the right, three across, three to the left. This first Charleston is mandatory. A second Charleston (left, across, right) is optional and only happens if every player agrees. After that, an optional courtesy pass lets you swap up to three tiles with the player across from you, by mutual agreement. Blind passing, sending on tiles you have not looked at, is allowed on the second and third passes of a Charleston, never on the first pass or the courtesy pass. Jokers may not be passed in a Charleston.
Taking turns: draw and discard
Play moves to the right, starting with East, who discards first. On your turn you either draw the next tile from the wall or call the tile just discarded, then you discard one tile face up and name it out loud. A discard is final once it touches the table. You always end your turn holding thirteen tiles counting any exposed sets.
Calling and exposing
You may claim the most recent discard, before the next player draws, to complete a pung (three identical tiles), a kong (four), or a quint (five, jokers required). You may claim a discard for a pair only when that pair completes your winning hand. There is no calling for runs. When you call, you expose the whole completed set face up on your rack, then discard. A call for mahjong beats a call for a set; between two set calls, the player nearer the discarder's right wins.
Jokers
A joker may stand in for any tile inside a pung, kong, or quint. It may never be part of a pair, never a single tile, and never used in a hand line the card marks as jokerless. A joker sitting in any player's exposed set may be redeemed by any player on their turn by handing over the real tile it represents; the joker then goes into that player's rack. Discarded jokers are dead and cannot be called.
Dead hands
A hand is dead when it can no longer legally win: an exposure that matches no card line, an exposure on a hand the card requires to be concealed, or the wrong number of tiles. A dead hand keeps drawing and discarding but cannot declare mahjong. If a player declares mahjong in error, their hand is dead; most groups also have them pay a penalty.
Winning
You win by declaring mahjong when your fourteen tiles exactly match a line on the current card, either by drawing the final tile or by calling it. Concealed hands must be completed without calling any discard except the winning tile. If the wall runs out with no winner, the hand is a wall game and nobody pays.
Scoring and payment
Each card line carries a point value. On a win, all three opponents pay the winner. The standard conventions: if the winner drew the final tile, everyone pays double; if the winner called it from a discard, the player who threw it pays double and the other two pay the base value. Many groups add bonuses for jokerless hands. Settle house rules before the first deal.
Put it into practice
A fresh coached hand every morning, the coach on call for your own tiles, all ten lessons and the 14-day course. $14.99 a month, cancel anytime.
Rules are the easy part to look up. The hard part is looking at thirteen real tiles and knowing which of those hands they are pointing at. That is what our AI coach does, free, on your own tiles.