You have one beat — roughly the time it takes the next player to reach for the wall — to claim a discarded tile. Speak in that window and it is yours. Miss it and the tile is gone, and no amount of "I was going to say something" brings it back.
Why the window is that short
Every turn in American mahjong runs the same loop: a player discards, the next player draws from the wall, racks, then discards. There is no queue of pending claims and no ruling to appeal to. A discard is either live or spent, and the moment that separates the two is the next draw.
That is why the rule is written in terms of an action rather than a count of seconds. The standard wording is: speak before the next player draws from the wall. Not before they rearrange their rack, not before they decide what to throw — before they take a tile off the wall. Once that tile is in their hand, your claim is void.
This is tighter than most beginners expect. Coming from games where a discard sits in the middle until somebody objects, they pause, weigh it up, and lose the tile by half a second.
What you are allowed to call it for
A live discard may be claimed for exactly four things:
- a pung (three of a kind)
- a kong (four of a kind)
- a quint or sextet (five or six of a kind, on the lines that ask for them)
- Mah Jongg, the tile that completes the whole hand
Notice what is absent. There is no call for a pair, and no call for a sequence. American mahjong has no chows at all: if your line wants 3-4-5 in one suit, you must draw all three yourself. Watching the 3-bam sail past is not a missed claim, it is just bad luck. Pairs work the same way, with one exception — the tile that completes your winning pair can come off a discard, because at that point you are not calling a pair, you are calling Mah Jongg.
The full turn loop is laid out on the game flow page.
A hand that turns on one beat
You are about three tiles from finishing a line. In your rack: a pair of 5-dots, a half-built group for a second line, and a few tiles you have not placed yet. A pung of 5-dots would complete half your hand, but exposing it commits you permanently to that line. Your line is marked X, so exposing is legal — irreversible, but legal.
The player opposite names "5 dot" and pushes it into the middle of the table.
You have perhaps two seconds. The real question is whether you want to lock the line now or keep your options open. That is a genuine strategic decision and it deserves thought — but not now. Now is the moment to speak. If you want it, say "Pung" before anyone touches the wall.
You can recover from the strategic mistake later in the hand. You cannot recover from the timing mistake at all.
So you call it, expose the three 5-dots, and discard. Two rounds later the fourth 5-dot appears; you call "Kong", expose four, and take a replacement tile from the wall. The hand pays. Had you spent those two seconds deciding, the tile would already be racked by someone else and you would still be three tiles away.
Three mistakes that cost hands
Waiting until you are sure. Beginners treat a call as a formal declaration, so they verify their rack first. The window closes during the verification. Read your hand before the discard is named, so the decision is already loaded.
Calling a run. Every year someone tries to claim a discard to finish a sequence, because they have played a variant that allows it. There are no chows in the American game. If your line needs a run, you draw it — see the card page for how runs are written.
Calling quietly. A mumble is not a call. Say the word: "Pung", "Kong", "Mah Jongg". Loud enough for the table, and before the draw.
And the expensive one: calling Mah Jongg on a tile that does not actually finish a line. The call is binding. If the hand does not match a line on the card the moment you lay it down, it is dead on the spot — no take-back, no partial credit. Details in dead hands.
Two edge cases worth knowing. If two players want the same discard, a call for Mah Jongg outranks a call for a pung or kong; between two identical claims, priority goes to the next player in turn order. And a joker exchange still has to happen on your own turn, after you have your tile — calling a discard does not let you reach across early. Both are covered in the rulings collection and on the jokers page.
One sentence worth keeping: the discard is not yours until you say so out loud, and it stops being available the instant the next hand touches the wall.