TL;DR: American mahjong has no chows. You cannot call a discard to close three consecutive numbers, and there is no run to lay on the table. The card still has a Consecutive Run section, and it means something else.
If you learned mahjong in China or Japan, or from an app that taught you riichi, the first American table feels like a different game wearing the same tiles. The wall goes up the same way. The rack looks familiar. Then someone discards a 3 of dots while you are holding 1 and 2, and your hand moves before your brain catches up. That is the moment this article is about.
The rule in one line: American mahjong has no chows. You cannot call a discard to finish three consecutive numbers, and there is no run to lay on the table. The card still has a Consecutive Run section, and it means something else.
What a chow is
A chow is a move. You hold two tiles that sit next to each other in the same suit, someone discards the third, you call it and put all three down. Chinese and Japanese mahjong both use it.
A chow would be three different tiles sitting in one group. The groups you can call are all copies of one tile: three 7 bams, four green dragons, or a quint and a sextet once jokers take the extra seats. There is no slot in the structure where three different tiles could go, so the move has nowhere to happen.
The card does print tiles side by side that are not copies. NEWS is one of each wind. A year hand is four singles that spell out 2026. Some singles-and-pairs hands use 123 or 2468. Those are single tiles, not groups, and it is precisely because they are single that no joker can stand in for one.
This is where the confusion usually starts. A printed 123 on the card looks, at a glance, like the run you would call in riichi. It is not a group. It is three single tiles that happen to sit next to each other on the page, and the only discard they can take is the one that completes the hand. Otherwise you draw them, one at a time.
Then what is a Consecutive Run?
Open the card and you will find a section with that name, which is exactly why the short answer confuses people. The section is real. It just is not about laying down a row of tiles.
A Consecutive Run hand asks for groups whose numbers step up with no gap between them: three 1s, then three 2s, then three 3s, then three 4s, and a pair. Four groups and the pair make fourteen tiles, which is the fixed size of every hand in the game. Not every line on the card looks exactly like that. Some mix pungs with pairs, and some run the same three numbers twice in two suits. What they all share is the part that matters here: the number climbs from one group to the next, and it climbs by one.
Every group is still identical tiles. What runs is the sequence of numbers from one group to the next, not a line of tiles on the felt.
So the word is doing two jobs. In Chinese and Japanese play, a run is something you build on the table out of three different tiles. In American play, a run is the shape of the hand, described by the numbers printed on your pungs. Same word, different layer of the game.
| Chow | Consecutive Run | |
|---|---|---|
| What it is | A move you make | The shape of a hand |
| Made of | Three different tiles | Groups of identical tiles |
| Where the numbers run | Inside one group | Across groups |
| Where it comes from | A discard you call | Your own draws |
Why the joker rules give it away
If you want proof that a run is not a group, look at what a joker is allowed to be. A joker stands in for a tile you are missing, but only inside a group of identical tiles: a pung, a kong, a quint, a sextet. It cannot be a single tile. It cannot be half of a pair. It cannot fill the gap between two numbers.
That last restriction looks arbitrary until you see the structure underneath it. There is no group made of consecutive numbers, so there is nothing for a joker to fill. A joker is allowed to be the fourth 7 bam. It is never the 2 that would turn a printed 1 and 3 into a chow.
A joker can still show up in a Consecutive Run hand. It just has to sit inside one of the groups, standing in for one copy of that number. It never stands in for the step between two numbers.
What this changes at the table
Discards matter less to you. Calling only ever gets you identical tiles, and identical tiles are the raw material of pungs, not of a climb. A Consecutive Run hand takes nothing from a call that would move it up a number, so it has to be built one draw at a time. Long stretches go by with your mouth shut.
A called tile tells you less than it would in riichi. If a player exposes 4 dots, the 3 and the 5 are not suddenly dangerous. Japanese mahjong trains you to read those neighbors because a called run uses them. Here an exposure is always copies of one tile, so the tiles on either side of it say almost nothing about what that player still needs.
Pick a direction early. The numbers in these hands have to climb, and the tiles that let them climb are scattered across three suits. The earlier you settle on which climb you are on, the fewer tiles you throw away that you will want back in three turns.
The short version
Chow is a move. Run is a shape. American mahjong took away the move and kept the shape, which is how a card with a Consecutive Run section can also say, truthfully, that there are no chows.
If someone tells you American mahjong has no runs, they are half right, and the half they are wrong about will cost you hands.