Mahjong Classic is the tile-matching solitaire built from a mahjong set — not the four-player gambling game, but the single-player puzzle where 144 tiles are stacked into a layout and you remove them two at a time. A tile can only be taken if it is 'free': nothing on top of it, and at least one of its left or right edges clear.
The skill is entirely in the order. Matching the first pair you see is how a layout locks up with four identical tiles stacked on each other and no legal move left. Play with the stacks in mind and the same layout that felt impossible unravels.
Remove matching pairs of free tiles. A tile is free when nothing sits on top of it and either its left or right side is open. Clear all 144 tiles to win.
No. Traditional mahjong is a four-player game of drawing and discarding tiles. Mahjong solitaire is a single-player puzzle invented in the 1980s that uses the same tile set.
Not always. Depending on how the tiles fall, a layout can become unwinnable — which is why the order you match in matters so much.