How to Play
Sliding number puzzles have a far more tangled history than they look. The original, the "15 Puzzle" (a 4×4 board with 15 numbered tiles), is believed to have been invented around 1874 by Noyes Palmer Chapman, a postmaster in Canastota, New York, who filed a patent application in March 1880. The puzzle craze it triggered was enormous: it broke out in the US in January 1880 and spread to Europe by April, with contemporary press describing it as an addiction "threatening our free institutions". Notably, famous puzzle designer Sam Loyd claimed from 1891 onward that he had invented it — a claim he repeated for decades until his death in 1911, even though his name was never connected to the puzzle in any coverage from the 1870s-80s. Puzzle historians consider it one of the most successful hoaxes in game history.
This app's Sliding Puzzle uses a smaller 3×3 board (8 numbered tiles plus one blank space) — friendlier for newcomers than the classic 4×4 15 Puzzle, but built on the exact same sliding logic. Tap any tile next to the blank space to slide it, and rearrange until 1 through 8 sit in order. The board is always shuffled by replaying legal moves backward from the solved state, so every puzzle is guaranteed solvable. Your final score is based on how many moves it took — fewer is better.
Tips
The efficient way in is to solve it piece by piece, not by sliding randomly until things line up.
- Solve the top row first (get 1 and 2 into place), then the left column — the rest of the board becomes a much smaller, easier puzzle once that's locked in.
- If placing a tile requires moving one you've already placed correctly, don't just slide it aside carelessly — rotate the blank space around it in a 3-move loop so the already-correct tile ends up back where it belongs.
- Keep the blank space near whatever region you're actively solving instead of letting it wander to the far side of the board.
- Since scoring is based on move count, avoid shuffling correctly-placed tiles back and forth just to think — plan your next few moves before touching the board.