Mahjong solitaire rules and terms, explained

In one paragraph: mahjong solitaire is a single-player puzzle played with mahjong-style tiles arranged in a stacked layout. A tile is free when no tile sits on top of it and at least one of its long sides, left or right, is open. You remove free tiles two at a time when they match, and you win by clearing the whole board. It shares tiles with mahjong but nothing else: there are no opponents, hands or melds.

The free-tile rule

Every version of the game uses the same two tests. A tile is blocked if any tile overlaps it from the layer above, even partially. A tile is also blocked if it has neighbours touching it on both the left and the right on its own layer. A tile that passes both tests is free and can be selected. Tiles that are half-offset from their neighbours still count as touching, which is why some rows look open but are not.

In Meow-Jong this is exactly what the code checks: no tile within one cell on the layer above, and not flanked on both sides. The grid is 34 by 20 half-tile cells and 5 layers deep, so a tile can sit a half-step off its neighbours in either direction.

Matching

Two free tiles match when they show the same face. Traditional sets have 144 tiles: 34 faces that appear four times each (the three suits plus winds and dragons), plus four flowers and four seasons. Flowers match any flower and seasons match any season, even though the pictures differ. Many modern games drop the flower and season exception. Meow-Jong uses 44 cat pictures and the strict rule: a cat only matches the identical cat.

Layouts

A layout is the shape the tiles are stacked in before the deal. The best-known is the Turtle (also called the Shanghai or Dragon layout): 144 tiles in five layers, widest at the bottom with a single tile on top. Games add many others, from animals and letters to abstract shapes. The number of tiles per layout varies with the shape; Meow-Jong's boards run from 28 to 160 tiles. Fewer tiles do not always mean an easier board. Tall, narrow stacks are harder than wide, flat ones because each column hides the tiles beneath it.

Dealing, and why a random deal can be impossible

After the layout is chosen, the faces are dealt onto the positions. If faces are assigned purely at random, nothing stops the deal from hiding a face's only partners where they can never both be free at once. The simplest dead case is four identical tiles stacked in one column: the top one is free, but the one beneath it is never free while its partner is sitting on it. More common are subtle cases where every available move leads to a position with no matches left.

There are two standard remedies. Reverse dealing builds the board by repeatedly choosing two free positions, giving them a matching face, and removing them, until the layout is empty; playing those pairs back in order is a guaranteed solution. Reshuffle re-deals the remaining tiles when you are stuck. Meow-Jong deals in reverse and offers reshuffle, hint and undo. For how often purely random deals are solvable, measured on real layouts, see Is mahjong solitaire always solvable?

Getting stuck on a solvable board

A solvable deal still lets you make losing moves. If three copies of a face are free and you match the wrong two, the fourth may end up with no reachable partner. Our measurements show that random, hint-free play gets stuck on a large share of solvable deals, which is why undo and hint exist.

Strategy that actually helps

Work on the tallest stacks and the longest rows first; they hide the most tiles.
Prefer a match that frees more tiles over one that frees none.
When all four copies of a face are free, take both pairs; it can never hurt.
When only three copies are free, look at where the fourth is before choosing which two to match.
Use undo rather than reshuffle when a mistake is recent; a reshuffle throws away the board's structure.

Terms

Term	Meaning
Free tile (open tile)	A tile with nothing on top and an open left or right side.
Layout (board)	The arrangement of tile positions before the deal.
Deal	The assignment of faces to positions. Random or reverse-constructed.
Turtle	The classic 144-tile, five-layer layout.
Flowers and seasons	Two groups of four distinct tiles that match within the group in traditional sets.
Reshuffle	Re-dealing the remaining tiles when no match is available.
Shanghai	Activision's 1986 game that popularised the genre; also used as a name for the game itself.

A very short history

The computer version is usually traced to Brodie Lockard, who wrote a mahjong solitaire program on the PLATO system in 1981 and later worked with Activision on Shanghai (1986), the game that made the Turtle layout famous. Microsoft shipped its own version with Windows Vista in 2007 as Mahjong Titans, which is where many people first met the puzzle. The genre is sometimes called "mahjong" on its own, which causes the confusion with the four-player game. Background: Mahjong solitaire on Wikipedia.

About the authors: these pages are written by EPWH LLC, the publisher of Meow-Jong, a cat-themed mahjong solitaire for Steam (Windows, macOS, Linux) and iOS. Edition details reviewed October 11, 2026. Review statistics below retain their original observation date.

Mahjong solitaire rules and terms.