ToolsJoker Rule Checker
Mahjong Joker Rules Checker
Pick a situation and get a plain-English ruling on whether a Joker move is legal in American Mahjong.
Answer these five questions about the exchange.
Choose a situation to see the ruling.
Based on commonly published National Mah Jongg League rules. Tournaments can be stricter and house rules vary, so confirm with your table. Unofficial fan tool, not affiliated with the National Mah Jongg League.
Joker rules at a glance
| Situation | Allowed? | Note |
|---|---|---|
| Pung, kong, quint or sextet | Yes | Jokers can replace any tile in these groups. |
| Pair | No | Pairs must be natural tiles. |
| Single tile | No | Applies to any hand built from single tiles. |
| Passing in the Charleston | No | Jokers stay on your rack. |
| Discarding a Joker | Yes, but it is dead | No one can call it. |
| Exchanging for an exposed Joker | Yes, on your turn | After you pick and rack, or call and expose. Exact tile only. |
| Exchanging with a discarded tile | No | Discards can only be called for new exposures or to win. |
How Jokers work in American Mahjong
Jokers are wild, with limits. A Joker can stand in for any tile in a group of three or more identical tiles, which means pungs, kongs, quints and sextets. It can never be part of a pair or stand in for a single tile, so hands built from pairs and singles must use natural tiles only.
Jokers can also move around the table. On your turn, once you have picked and racked a tile or called and exposed a discard, you can swap the exact natural tile for a Joker sitting in an exposed group. The Joker joins your rack, and you finish your turn by discarding or declaring Mahjong.
Two things Jokers cannot do: they cannot be passed in the Charleston, and a discarded Joker cannot be called by anyone. For the full picture, read our Joker rules and tips guide, our Charleston guide and our American Mahjong rules. For official rulings, see the National Mah Jongg League.
Joker rule questions
Can you use a Joker in a pair?
No. A Joker can never be part of a pair or stand in for a single tile. Jokers only work in groups of three or more identical tiles: pungs, kongs, quints and sextets.
Can you pass a Joker in the Charleston?
No. Jokers cannot be passed in the Charleston, so if you are dealt one, it stays on your rack. See our guide to the Charleston for what you can pass.
Can you call a discarded Joker?
No. You may discard a Joker, but a discarded Joker is dead. No one can call it for an exposure, an exchange or Mahjong.
When can I exchange a natural tile for a Joker?
Only on your own turn, and only after you have picked a tile and racked it, or called a discard and exposed it. You then swap the exact natural tile the Joker stands for. After the exchange you must discard or declare Mahjong.
Can I use a discarded tile to take a Joker from an exposure?
No. A discarded tile can only be called to make a new exposure or to win. If the tile that matched an exposed Joker was discarded and nobody swapped for it, that chance is gone.
Does winning with a Joker exchange count as a self-pick?
Under standard scoring it does, so every other player pays double. Check your table’s rules, then use the Payout Calculator to work out the amounts.
How many Jokers are in an American Mahjong set?
A standard American set has 152 tiles, including 8 Jokers.
Do these answers apply in tournaments?
They cover the rules most players follow at home and in clubs. Tournaments can be stricter, for example by ruling a hand dead for a procedural mistake. For official rulings, check the National Mah Jongg League’s rulebook and bulletins.
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