American Mahjong Table Dispute Cheat Sheet & Arbiter Manual (2026)

Authoritative tournament rulings for immediate conflict resolution during American Mahjong game nights.

Pillar 1: Joker Legality & Substitution Protocols

Under official National Mah Jongg League (NMJL) rules, Jokers are powerful wildcards with rigorous boundaries:

Permitted Uses: Jokers may substitute for any tile in a Pung (3 matching tiles), Kong (4 matching tiles), Quint (5 matching tiles), or Sextet (6 matching tiles).
Prohibited Uses: Jokers may NEVER represent singles, pairs, or year dates (such as 2-0-2-6). Placing a Joker in a pair results in an immediate dead hand.
Exchange Rules: On your turn, after you have drawn a tile from the wall, you may replace an exposed Joker on another player's rack with the exact matching natural tile from your concealed hand. You cannot swap a Joker before drawing or during someone else's turn.
Dead Hand Jokers: Jokers exposed on the rack of a player whose hand has been declared dead are permanently frozen and cannot be exchanged.

Pillar 2: Dead Hand Declarations & Penalties

A hand is legitimate declared dead only under specific violations:

Tile Count Errors: The player holds fewer than 13 tiles or more than 14 tiles (13 when not their turn, 14 after drawing).
Illegal Melds Exposed: Exposing a combination not valid on the 2026 card, or exposing a pair with a Joker.
Mathematical Impossibility: All remaining tiles needed for an exposed hand are accounted for in discards or other racks.

Penalty for False Accusation: If a player declares another player's hand dead erroneously, and the accused player demonstrates legality, the accused player continues playing. If the accuser exposed their own tiles during the dispute, the accuser's hand is declared dead instead.

Pillar 3: Simultaneous Discard Claims & Timing Window

When multiple players attempt to claim the same discarded tile simultaneously:

Mahjong Hierarchy: A call for Mahjong takes absolute precedence over any call for an exposed set (Pung, Kong, Quint), regardless of table position.
Turn Order Priority: If two players call for an exposed set (and neither is calling for Mahjong), the player closest to the discarder's right in normal clockwise rotation wins the tile.
Window of Opportunity: The right to call a discarded tile permanently closes the moment the next player in turn draws a tile from the wall and places it into their rack, or completes their discard.

Pillar 4: Charleston Passing & Blind Passing

Key disputes during the pre-game passing phase:

Blind Pass (Steal): On the 3rd pass of each Charleston (First Charleston: Pass Left; Second Charleston: Pass Right), a player who does not wish to part with 3 tiles from their hand may blind pass 1, 2, or 3 received tiles directly to their target without looking at them.
Stopping the 2nd Charleston: Proceeding to the Second Charleston requires unanimous consent of all 4 players. Any single player who says "STOP" cancels the Second Charleston, advancing play immediately to the Courtesy Pass.
Courtesy Pass Protocol: Across players may agree to pass 0, 1, 2, or 3 tiles. The lower number requested by either player always governs the exchange.