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American Mahjong School

Kongs & replacement tiles

A kong is four identical tiles. Simple idea — but the timing, the replacement draw, and the joker rules around it are where good players quietly pull ahead.

Right vs. wrong at a glance

We use real vector tile faces so they stay sharp when enlarged. Below we show only the tile-count structure of a kong — draw and scoring details follow official NMJL rules.

✓ Right: four identical = kong

Exactly four identical tiles can be declared a kong, after which you draw one replacement tile from the wall.

✗ Wrong: three-plus-one is not a kong

Three identical plus one different is just “a pung and a loose tile” — not a kong, so no replacement draw.

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Kongs & replacement tiles

A kong is a group of four identical tiles. Like a pung, it can be called from a discard or built from your hand — but a kong triggers a replacement draw, and that replacement comes from a specific place on the wall.

The one rule that surprises everyone

You may not call a discard to make a kong in order to win. A kong call means you then draw a replacement tile from the dead wall — you cannot declare Mah Jongg off a kong call. If the 4th tile would complete your hand, you must claim it as the winning tile (Mah Jongg), not as a kong. Calling a kong to go out is an illegal call and can dead your hand.

The three kinds of kong

#TypeHow it happensReplacement?
1Concealed kongYou hold all four tiles in your hand (often by drawing the 4th). Declared without calling a discard.Yes — from the dead wall
2Exposed kongYou call a discard to complete four of a kind (you already hold three like tiles, jokers allowed) .Yes — from the dead wall
3Added kongYou already have an exposed pung, then draw the 4th tile and add it to the group.Yes — from the dead wall
The three kinds of kong
1 · Concealed 2 · Exposed 3 · Added D5 D5 D5 D5 WS WS WS J WS WS WS WS All four drawn into your hand — declared with no call. Made by calling a discard; jokers allowed in the group. A pung exposed, then you draw and add the 4th tile.
Every kong — of any kind — lets you draw one replacement tile from the dead wall.

The replacement tile comes from the dead wall

Whenever you make a kong — any of the three kinds — you draw one replacement tile. In American mahjong under NMJL rules that replacement comes from the dead wall (the back end of the wall reserved for this purpose), not the live wall in front of you. Flowers work the same way: draw a flower, take a replacement from the dead wall. Treat the dead wall as a separate stack — reach to the back, not the live end.

Jokers in a kong

Any number of jokers

All-joker kongs are legal

A kong may be built entirely from jokers. The National Mah Jongg League confirms there is no minimum number of natural tiles required for a pung, kong, quint, or sextet — the group may consist of all jokers .

Before you call

Three like tiles in hand

To claim a discard for an exposed kong, you must already hold three like tiles (jokers may stand in for them) before the 4th is discarded. You cannot call a kong on a group you have not assembled .

Kongs and concealed hands

A concealed hand may include a concealed kong built from your own tiles, but it may not include an exposed kong, because calling the discard would break concealment and dead the hand. Keep any kong in a C hand face-down as a concealed kong.

Common kong mistakes

  • Calling a kong to win. Illegal — claim the tile as Mah Jongg instead. (See Dead hands.)
  • Drawing the replacement from the live wall. Always take it from the dead wall.
  • Exposing a kong in a C hand. Dead hand — keep it concealed.
  • Forgetting the replacement. A kong leaves you with 13 working tiles until you draw the replacement; you must draw before discarding.
  • Exchanging a joker too early. Joker exchange happens on your turn after you pick or call — never before.

Why this page exists

Kong timing and the dead-wall replacement are frequent sources of disputes and accidental dead hands. The details above follow the National Mah Jongg League standard as summarized by MahjLife's Article 4 (“Any number of jokers can be used in big multiples”), the American Mah-Jongg Association's Rules Companion, and the back of the official card. Where your table or tournament differs, the current official card and that table's house rules always win.