One tile in each colored region, one per row and column — and never touching another tile.
One tile in each colored region, one per row and column — and never touching another tile.
Every board is split into colored regions. Stand one real mahjong tile in each region — and exactly one tile in every row and every column. Two tiles may never sit next to each other, not even on the diagonal. There is always exactly one arrangement that fits.
On a phone: tap a square to stand a tile; press and hold to mark it as empty. On a computer: left-click to stand a tile — if it's the wrong square the tile shakes, you lose one of your three hearts, and the game tells you. Right-click to pencil-mark a square as definitely empty, which costs nothing and just helps you keep track.
The tiles are pure decoration. A region may show dots, bams, craks, winds, dragons, a flower or a joker, but none of that changes the rules — it only changes the view.