Can a fifth person play American Mahjong?
Four people play the hand, but a fifth can sit in as the Bettor. After the Charleston and before East's first discard, the Bettor picks the player most likely to win, keeps that choice private, and then says nothing at all until the hand is over. They collect or they pay exactly as the player they chose does.
Answered by Prim. Last reviewed 2026-09-21.
The fifth seat has a real job
Four hands are dealt and four people play them. That does not change. What the rules allow is a fifth person who takes no tiles, holds no rack, and instead stakes the outcome on somebody else's hand. She is called the Bettor, and she is a genuine participant with money on the table, not a spectator being kept busy.
A bet on a wall game is allowed too. If the Bettor looks at four unpromising racks and decides nobody is finishing, she may back that instead.
When the bet is placed, and how
The window is narrow and specific: after the Charleston is complete and before East makes the first discard. The Bettor walks the table, sees what everyone is holding at the moment the passing ends, and chooses.
The choice is written down or marked with a betting disk, and it is not announced. Nobody learns who was backed until the hand is settled. It also cannot be changed. A Bettor who watches her choice go quiet while another player lays down a third exposure has to sit with it, which is rather the point.
Silence is the whole discipline
From the moment the bet is placed until the hand ends, the Bettor says nothing. Not about the play, not about a tile, and not about a mistake she can plainly see being made. She has been to every rack. She knows more than anyone seated, and she is the one person who must act as though she knows nothing.
Interfering with play cancels the bet outright. That is the safeguard, and it is what keeps a fifth person from becoming a fifth opinion. If you cannot watch a player miss a call without making a face, the fifth seat is not for you.
How the money moves
If the player who was backed self-picks her winning tile, the winner and the Bettor each receive double from everyone. If she wins on a discard, only the discarder pays double and the rest pay single, and the winner shares with the Bettor. The League's recommendation is that all the money goes to the winner first and she then splits it, which keeps the arithmetic in one pair of hands.
A Bettor who chose wrong pays the winner exactly what her chosen player pays. She is tied to that player completely, in both directions. And a correct bet on a wall game collects the lowest value printed on the card from each player.
The simpler alternative, and a word before you start
Betting is not the only way to seat five. Many groups simply rotate: four play, the extra person sits out, and after a player has been East she steps out for the next hand so everyone cycles through. It is easier to explain, it costs nothing, and nobody has to hold their tongue for twenty minutes.
Whichever you choose, settle it before play begins. The Bettor is a social tradition more than a fixture of every game, and it is not usually part of tournament play. A table that agrees on it in advance never has to argue about it afterward.
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