BURYING A TILE IN THE WALL (Article 147)

Commentary: Before a game is played, players mix the tiles and build a wall in front of their rack, resulting in a continuous wall from which to play. Consider this a zen garden not to be disturbed by the players except for picking to start a turn and curtseying the walls so players can reach. If something happens where tiles in the wall are tipped, picked, and seen but not racked or otherwise disturbed, they need to be returned to their original spot to protect the continuity of the game. If someone attempts to alter the wall, they should be disqualified.

Question from a player: Player A picks from the wall and has the tile in her hand when Player B says that she wishes to call the previously discarded tile. Player A puts the tile back in the wall. Player C takes the tile that has been returned to the wall and mixes it up on the wall, saying that it was looked at and that she refuses to pick it up. What happens next?

Answer from NMJL: Once the tile has been called, and a tile has already been picked, not racked by the next player, the picked tile must be returned to the exact position from which it was originally positioned on the wall. Player C, who took the returned tile and placed it somewhere else now has a dead hand. If no one knows where she put the tile, the hand must be thrown in.

Source: NMJL Bulletin (2025)

Other answers from the NMJL:

If a tile from the wall is accidentally overturned, it must be returned to the same position from which it fell. It is not returned to another location in the wall

No.  You cannot place a tile in another/arbitrary position in the wall. You must keep the tile in the position it came from even if that tile has been seen by other players.

Other sources: Mah Jongg Made Easy (2024 page 31 paragraph 9); National Mah Jongg League Bulletin (2021)