Sources & how this guide is written

Primary references

• The National Mah Jongg League (NMJL) — the governing body founded in New York City in 1937. Publisher of the annual Official Standard Hands and Rules card and the authority on legal hands, joker restrictions and tournament procedure.
• The annual NMJL card — the definitive list of legal winning hands for the year in play, including each hand's printed point value, its concealed or exposed status, and any no-joker restriction.
• Standardized National Mah Jongg Tournament Rules — the codified tournament standard used at organized events across the United States and Canada.
• The American Mah-Jongg Association (AMJA) — the second annual card publisher. Mentioned where the choice of card affects play.
• Published reference works on American mahjong — used to cross-check tile composition, Charleston procedure, scoring convention and the historical record from the 1920s craze onward.

Where to verify it yourself

Every rule stated on this site can be checked against a primary source. These are the references we work from, and every article on the site links back to them:

• National Mah Jongg League (NMJL) — the official card and rulebook. The final authority at any table.
• American Mah Jongg Association — official rules — a readable restatement of NMJL-aligned play: walls and dealing, the Charleston, calling, exposures, joker restrictions, dead hands and the conditions for declaring mah jongg.
• AMA — beginner guide — equipment, tile composition and the object of the game, stated plainly.
• MahjongWiki — joker rules, uses & exchanges — the most detailed public treatment of where a joker may and may not stand, and the exact exchange procedure.
• Mahjong Compare — complete rules guide — calling priority, exposure rules and winning conditions.

Our own deep dives

Where the standard rules meet the situations that actually cause arguments, we work them through in full:

• Rulings & case library — dead hands, the not-viable call, the window in which an exposure can still be corrected, contested discards, and the exact joker exchange procedure.
• The Charleston: a decision manual — pass order, blind passes, the second Charleston, the courtesy pass, and how to read the nine tiles that move before play begins.
• The 2026 NMJL card: what actually changed — the PKPK → PPKK shift, the return of the sextet after twenty years, and what both do to your opening.
• Tournament play — seating, the tightened Charleston, calling discipline, score verification, bonuses/penalties, table rotation, and the major championships under the Standardized National Mah Jongg Tournament Rules.
• Rule variants: NMJL, Wright-Patterson & AMJA — how the three American families differ in tiles, jokers, valid sets, and scoring.
• Defensive play — reading exposures, safe vs. danger tiles, counting jokers, and when to fold.

References behind the tournament, variant & defensive pages

• Standardized National Mah Jongg Tournament Rules (R8) — the codified tournament standard (card on display, zero-tolerance, East/deal, score verification, Charleston, no pick-ahead, blind-pass penalty).
• MahjLife Mini-Tournament Rules — representative bonuses and penalties (self-draw +10, no-joker +20, dead 0, feeding a ready hand −10/−20/−25) and table rotation schemes.
• Crisloid — 2025 Mah Jongg World Championship — Destination Mah Jongg's 10th anniversary championship announcement: Las Vegas, October 24–26, 2025, the Golden Ticket path from NMJL-sanctioned tournaments, and the event's standing as the largest prize purse in American Mah Jongg history.
• American Mah Jongg Association — Destination Mah Jongg events — ongoing listings of Destination Mah Jongg championship and qualifying events, including the recurring Las Vegas championship and associated tournament travel packages.
• MahjLife — Wright-Patterson Mah Jongg — the W-P tradition: 144 tiles, no jokers, chows allowed, emphasis on concealed hands, and the Green Book of special hands.
• Tom Sloper — the AMJA card — the AMJA alternative card: family-named hands, word-spelling hands, jokers allowed in singles/pairs when indicated, higher values, and a callable first-discard joker.
• American Mah-Jongg Association — Rules Companion — a readable restatement of NMJL-aligned legality (tile count, calling, concealed/exposed, jokers, dead hands).
• Mahjong Compare — strategy & defense and BamCrak — defensive play — competitive guidance on exposures, danger tiles, the discarded-joker tell, and folding. (Interpretive, not rulebook.)