Exposed vs. Concealed Hands in American Mah Jongg

The final letter on a card line changes how you may build it:

• X means exposed. You may call legal discards and display qualifying groups.
• C means concealed. You must build the hand without exposing groups during normal play.

Read the full notation guide in How to Read the American Mah Jongg Card.

What an Exposed Hand Allows

For an X hand, you may call the most recent discard to complete a permitted Pung, Kong, Quint, or other qualifying group. Place the entire group face up on the rack. Those tiles remain part of your 14-tile hand.

Exposed does not mean every tile must be visible before winning. It means the line may include legal exposures. Your uncalled tiles stay concealed on the sloped side of the rack.

What a Concealed Hand Requires

For a C hand, do not call a discard to expose an ordinary group. Build by drawing from the wall. You may generally call the final discarded tile if it completes the entire hand and you immediately declare Mah Jongg.

Calling and exposing a group while pursuing a concealed line can make that line impossible. Learn how that affects play in What Makes a Hand Dead?.

Can a Concealed Hand Use Jokers?

Concealed does not mean “no Jokers.” Under standard play, Jokers may still substitute within eligible groups of three or more identical tiles. They cannot replace required singles or pairs. The hand must remain concealed until it wins.

See How to Use Jokers for legal placements and exchanges.

Common Beginner Misreadings

• Treating X as “same number” instead of Exposed
• Assuming an X hand must expose something
• Calling a tile for a C hand before Mah Jongg
• Believing all concealed hands forbid Jokers
• Hiding a called group instead of displaying it immediately
• Mixing exposed groups from one line with concealed tiles aimed at another

Choose the Right Difficulty

Exposed hands can be easier for early practice because calls provide additional ways to obtain tiles. Concealed hands preserve information but depend more heavily on wall draws. Choose based on your rack and the card—not because one label is always better.

Before calling, revisit Calling a Tile: Pungs, Kongs and Quints. When close to winning, use the checklist in How to Declare Mah Jongg.

A Comfortable Home Setup

Readable faces and sturdy racks help keep exposures visibly separate. Browse American Mahjong tile sets.

Continue Learning

Next: How to Declare Mah Jongg

Rules note: Use the current card and the rules governing your table. Tournament procedures and house corrections may differ.