Right vs. wrong at a glance
We use real vector tile faces so they stay sharp when enlarged. Below we show one key difference among the major American families — full rules follow each family’s own authority.
NMJL (standard American) uses 8 jokers — its most distinctive signature — and generally does not allow chows.
Wright-Patterson is a genuinely separate branch: 144 tiles, no jokers, chows allowed. Applying NMJL’s joker rules there is simply wrong.
Rule variants
Most clubs, teachers, and tournaments you will meet play the NMJL standard. Two other families exist: Wright-Patterson, a distinct military-base tradition, and the AMJA, an alternative card within the American family. Knowing the difference saves you from showing up with the wrong rulebook.
| Dimension | NMJL (the standard) | Wright-Patterson | AMJA (alternative card) |
|---|---|---|---|
| Tiles | 152 (108 suits + 16 winds + 12 dragons + 8 flowers + 8 jokers) | 144, no jokers | 152 (8 jokers), played on the AMJA's own card |
| The card | Annual NMJL card; hands listed by number/pattern | "Green Book" booklet of 70–100+ special hands; stable ~6–10 years | Annual AMJA card — an alternate to the NMJL card |
| Jokers | Wild in groups of 3+ ; never in singles or pairs | None in the game | Wild as NMJL ; published AMJA guidance keeps the same singles/pairs restriction, so check whichever code your group adopted |
| Valid sets | Pung, kong, quint, sextet; no chows | Chows (sequences) are valid — closer to Chinese/Cantonese style | Same family as NMJL (no chows) |
| Charleston | Yes — right, across, left, then optional reverse | Yes, but its passes and direction differ from NMJL's | Yes (same family as NMJL) |
| How you win | Match any one line on the current card | Only on a listed special hand from the booklet | Match a line on the AMJA card |
| Concealed play | Marked (C) on the card | Emphasizes concealed hands; rewards subtle play | Marked (C) on the card |
| Discarded joker | Never pickable — a dead tile | n/a (no jokers) | May be called, but only as the first discard of the game |
| Scoring | Winner collects the card value; self-draw / discarder / jokerless doubles | All players earn points; East pays and receives double | Higher values — lowest ~35 points, top hand 100 points |
| Origin | National Mah Jongg League, 1937 | Officers' Wives Club, Wright-Patterson AFB, 1920s | American Mah-Jongg Association, founded 2000 |
NMJL — the standard you will meet most
When a teacher, club, or tournament says "American mahjong" without qualification, they mean NMJL rules: the 152-tile set, the annual card, jokers as group wilds only, the Charleston, and calling discards for pungs, kongs, quints, and sextets. This entire site teaches that standard. Learn it first; the others are easier once you know the base game.
Wright-Patterson — a different tradition
Wright-Patterson (W-P) grew out of the Officers' Wives Club at the Wright-Patterson Air Force Base in the 1920s and still travels with military families. It is played with a standard 144-tile set and no jokers, permits chows (runs) as valid sets , leans on concealed play, and — unlike NMJL — you can only win on one of the many named special hands in its booklet (the "Green Book"). Scoring is also Chinese-style: points accrue for everyone at the table, and East pays and receives double. If you meet W-P, expect a very different rulebook; the NMJL card will not help you.
AMJA — an alternative card, same family
The American Mah-Jongg Association publishes its own annual card as a fun alternative to the NMJL card; many groups play the same mechanics but switch cards. The AMJA card is recognizable at a glance: hands carry witty family names (for example "Don't Get Mad — Get Even" for the evens family), can spell words with tiles (using 1 as "I" and the white dragon as "O"), and assigns higher values than the NMJL card. Its most important rule twist: jokers may appear in singles and pairs — but only on hands that explicitly call for them. (Under pure NMJL rules, jokers are never legal in singles or pairs.)
Home & table variants (not NMJL)
Beyond the three families above, American players have invented plenty of house and table variants — informal ways to adapt the game when you don't have a full table, or playful traditions a group enjoys. None of these appear on the NMJL card, and the exact mechanics vary from household to household. Treat them as fun, not as rules you can rely on at a club or tournament.
Ghost — three players
With only three players, the empty fourth seat becomes a "ghost": a hand is still dealt to it and its turns are auto-played, so the Charleston and the wall work exactly as in a four-player game. A common workaround — not NMJL.
Siamese — two players
A two-person adaptation where each player also runs a second "partner" hand (or dummy hand), keeping the full 152 tiles and a normal Charleston in play. House rules decide how the second hand is handled. Not NMJL.
Heavenly Hand
When East wins on the very first tile drawn, before any discard. Many groups treat it as a lucky event and may toast or award a bonus — but it is not a scored category on the NMJL card. Under strict rules it is simply a normal win.
Bird Bam
The 1-bam tile is nicknamed the "bird" because it pictures a bird rather than a single bamboo. Some home groups have a playful tradition around it (for example a toast when it is the winning tile). Purely social — not a rule, and not on the card.
Which should you learn?
Start with NMJL — it is the common language of clubs, teachers, and tournaments. Explore Wright-Patterson only if you are in military-circle play. Try the AMJA card when your group wants a change of pace without leaving the American family. Where a table or tournament differs from anything here, that table's card and house rules always win.
Why this page exists
Players routinely confuse these three. The comparison above is built from each tradition's own published rule materials, the American Mah-Jongg Association's Rules Companion, and the NMJL standard. The NMJL facts match the rest of this site; the W-P and AMJA columns describe genuinely separate traditions and are labeled as such.