American Mahjong PIE FAQ
Fourteen answered questions about PIE (Purse Is Empty): the rules, the money, the edge cases — and how the free calculator handles them.
What is PIE in American Mahjong?
PIE stands for “Purse Is Empty.” Mahjong teaching sources describe it as a table-agreed house rule: players pay losses from a fixed purse and stop paying when it is empty. We did not find a current first-party NMJL statement confirming that status.
How much money should I bring for PIE?
Each table chooses 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 starting.
What does it mean to go bust?
Going bust means your purse is empty. You keep playing but stop paying until winnings refill your purse. If the bust happens mid-round, the table either forgives the shortfall or tracks it as debt — agree on one before play.
My PIE was empty, then I won $1.50 back — do I pay if I lose the next 25¢ round?
That depends on your table. With automatic resume, yes: the player pays 25¢ from the $1.50. With manual restoration, the player stays busted until the table restores them. Public research did not verify either option as a standardized custom.
Do payouts come from my mahjong purse or my personal wallet?
Agree on this before play. This calculator can either forgive any amount above the remaining PIE or track it as debt, but public research did not verify either approach as a standardized custom.
What stops someone from emptying a PIE on purpose to avoid paying?
This is a table-agreement question. If your group wants unpaid amounts recorded, select debt mode. Debt is deducted first from the debtor’s own future winnings; it is not transferred to the earlier winner, and a busted player still incurs debt each round.
How does the optional Bettor work?
The Bettor picks one player before each round. A correct pick receives half of the winner’s actual collections from the other players, rounded down to the cent. A wrong pick pays the winner what the selected player actually paid. Draw bets are not tracked.
Can I use this if we do not play for money?
Yes. Set the starting PIE to $0 for pure scorekeeping. Purse, bust, shortfall, debt, restoration, and top-up logic are disabled, and each participant’s cumulative net may go negative.
Can one person run the calculator for the whole table?
Yes — that is the intended setup. One operator enters winners and amounts on a phone; everyone else just plays.
Do I need to install an app or create an account?
No. It runs in a mobile or desktop browser, with no signup and no download.
Does the calculator move real money?
No. It is record-keeping only: it tracks the amounts your table agrees on. Settle up however your group normally does.
How many players does it support?
Three or four players, with an optional Bettor mode for a fifth participant alongside four players.
I logged the wrong winner. Can I fix it?
Yes. Undo removes the most recent round and restores balances; starting a new game clears everything.
What happens if I refresh the page mid-game?
An unfinished game is autosaved in the browser. Reopening the page offers to resume where you left off or start fresh.
Is this tool affiliated with the National Mah Jongg League?
No. It is an unofficial fan-made tool, not affiliated with or endorsed by the National Mah Jongg League.
Put the answers into practice
The free calculator implements every option above — forgiveness or debt, automatic or manual recovery, the Bettor, and score-only mode.
Open the PIE calculator