What Is PIE in American Mahjong?

PIE stands for “Purse Is Empty.” It is a table-agreed house rule: each player sets aside a fixed purse at the start of the session, pays losses out of that purse, and stops paying once it is empty.

The basic idea

American Mahjong is often played for small stakes — a winning hand might be worth 25¢ or 50¢ under the card values. PIE puts a ceiling on the evening: before play begins, everyone agrees on a purse amount (say, $5). Every time you lose a round, the amount you owe comes out of your purse. When your purse hits zero, you are “busted” — you stop paying for the rest of the session, but you keep playing.

The point is social, not financial: nobody goes home having lost more than the agreed limit, and nobody has to do awkward mid-game math. One person can track every purse on a phone with the Mahjong Pie calculator while everyone else just plays.

Common PIE limits

Each table sets its own limit. One 2026 teaching source says $5 is common, with $10 or $20 used for higher-stakes play. Confirm the amount with your group before the first tile is drawn — the “right” number is whatever everyone is comfortable losing.

What happens when a purse runs out (“bust”)

A bust often happens mid-round: a player owes 25¢ but has only 10¢ left. Tables handle the shortfall in one of two ways:

• Forgive it. The player pays what is left, the remaining 15¢ is forgiven, and the purse sits at zero.
• Track it as debt. The unpaid 15¢ is recorded against the player and comes off their future winnings first.

Getting back in the game

A busted player is not out of the game. When they win a hand, the winnings refill their purse, and they can start paying again. Tables differ on the mechanics:

• Automatic resume: as soon as the purse has money again, the player pays normally.
• Manual restoration: the player stays busted until the table explicitly restores them.

The optional Bettor

Many groups add a fifth participant, the Bettor, who does not play but bets on each round. The convention this calculator follows: the Bettor picks one player before the round. A correct pick earns half of what the winner actually collected from the other players (rounded down to the cent), shared by the winner. A wrong pick pays the winner whatever the picked player actually paid. Drawn hands are not tracked for the Bettor. See the worked examples for exact numbers.

PIE and the NMJL

PIE is consistently described in mahjong teaching sources as a table-agreed house rule, not an official regulation. Our research did not find a current first-party statement from the National Mah Jongg League confirming its status either way — so treat the details above as common customs, and always confirm the rules at your own table.

Playing without money

Prefer pure scorekeeping? Set the starting PIE to $0. Purse, bust, debt, and top-up logic switch off, and each player’s cumulative net can go negative — a clean way to track a casual night.