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The Mahjong Guide symbolThe Mahjong Guide

Mahjong Calls and Exposures

A call claims the most recent discard and places it into a completed face-up group. Calls are useful because they can finish a needed pung or kong, but every exposure also reveals information and locks part of the hand into one interpretation.

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What a legal exposure requires

One current discard
Only the most recently discarded tile may be claimed.
One complete group
The discard must immediately complete a pung, kong, quint, sextet, or the entire winning hand.
Identical tile identity
All natural tiles in the group must be exact matches.
Compatible card line
The group must fit a real line the player can legally complete.
Permitted exposure status
A concealed hand cannot contain an ordinary exposure.

Legal and illegal reasons to call

Legal

The discard completes a three-or-more identical-tile group shown on the card, or completes mahjong.

Illegal

The discard merely improves the hand, completes only a pair during ordinary play, or is wanted for a possible future combination.

How to make the exposure

  • Call the tile before the next player completes a draw.
  • State the group, such as “three bam” or “north kong.”
  • Take the discard and place the complete group on top of the rack.
  • Arrange all tiles so the group is unambiguous.
  • Discard one tile to complete the turn.

An exposure is public information

Every exposed group tells opponents something about the possible card line, suit structure, and remaining needs. Strong play weighs the speed gained by calling against the information revealed.

Calling questions

Can a discard be called to exchange for a joker?

No. A natural tile used for a joker exchange must come from the player’s hand during the player’s own turn.

Can two players call the same discard?

Priority rules apply. A valid mahjong call outranks an exposure call; otherwise the nearest eligible player in turn order generally has priority.

Can a player expose a pair?

Not during ordinary play. A pair may be completed with a discard only when that discard gives the player mahjong.

Verify a Call Before Touching the Discard

  1. Name the exact group. Know whether the discard completes a pung, kong, quint, sextet, or the full winning hand.
  2. Check the card line. Confirm that the group appears in a real candidate hand and that the line may be exposed.
  3. Check tile identity. Natural tiles in the exposure must be exact matches, not merely related numbers or suits.
  4. Check joker eligibility. Jokers may represent identical tiles in eligible groups but cannot create a pair or single.
  5. Expose the complete group. Place every tile in the group together, then discard to finish the called turn.

Strategically Strong Calls and Weak Calls

Stronger Call

The exposure completes a difficult group, leaves a realistic path to fourteen tiles, and does not reveal more information than the gain justifies.

Weaker Call

The exposure completes an easy group but locks the rack into a brittle line, destroys a useful backup, or exposes a hand that still needs several scarce natural tiles.

Illegal Call

The discard does not complete a full printed group, the line must remain concealed, or the exposure uses a joker where only natural tiles are allowed.

Use calls correctly

Exposed vs. Concealed Mahjong Hands

Exposed vs. Concealed

Know which hands may call.

American Mahjong Dead Hand Rules

Dead Hand Rules

Avoid fatal exposure errors.

American Mahjong Turn Order

Turn Order

Resume play after a call.

Keep reading

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