What is Fortress layout?
The Fortress is a layout of all 144 tiles built as a walled fort seen from above. Walls two tiles high run round a square courtyard. At each corner stands a tower of four tiles stacked three storeys high with one more tile on top, and a keep rises in steps in the middle of the courtyard.
The rules are the standard ones. Take off two matching tiles at a time, as long as both are free: nothing lies on top of them and their left or right side is open. Clear the board to win.
Few tiles are free at the start. The four towers are the deepest stacks on the board, so the tiles at their foot stay hidden until the tower above them has been taken down pair by pair, and the long walls at the top and bottom run from tower to tower, so they open only once the towers beside them start to come down.
Rule changes
| Rule | Standard Mahjong Solitaire | Fortress layout |
|---|---|---|
| Layout | Standard Mahjong SolitaireThe Turtle: a broad block of tiles that rises in steps towards the middle. | Fortress layoutThe Fortress: walls round a courtyard, a tower at each corner and a keep in the middle, 13 tiles across. |
| Layers | Standard Mahjong SolitaireFour layers: 82, 40, 18 and 4 tiles. | Fortress layoutFour layers: 69, 53, 18 and 4 tiles. The towers reach the fourth layer, the walls the second. |
| Free tiles at the start | Standard Mahjong Solitaire32 of the 144 tiles. | Fortress layout30 of the 144 tiles. |
| Other options | Standard Mahjong SolitaireShuffles, a time limit and the random deal can be added in the setup. | Fortress layoutThe same options work on the Fortress: shuffles, a time limit and the random deal. |
History
Mahjong Solitaire began on a computer: Brodie Lockard wrote it for a university computer system in 1981, and a commercial version made it widely known in 1986 with a single layout, the Turtle. Later versions let players choose among layouts named after the shapes they draw.
A widely used version from the late 2000s offered six layouts: Turtle, Dragon, Cat, Fortress, Crab and Spider, each a stylised picture of its subject. The name has stayed in use, but no two programs draw their Fortress alike, and there is no standard Fortress layout. The one here is our own design.