Concealed vs Exposed Hands in American Mahjong

Every NMJL line is either exposed or concealed. That single mark changes how you play the wall. Exposed hands let you call discards for the sets the card allows. Concealed hands stay on your rack until you declare mahjong.

Exposed

You may call the most recent discard to complete a pung or kong that belongs on your line, then place those tiles on the rack facing the table. The table now knows part of your recipe. That is the trade: speed and information.

Concealed

• Do not call discards for sets. Draw from the wall.
• You may still call the discard that completes the entire hand — that is going mahjong.
• Concealed lines often pay more. The card is paying you for silence.

After the Charleston, read the mark before you fall in love with the numbers. A beautiful concealed line is dead if you have already exposed a pung for a different family.

• Read a card line →
• How a hand is won →