How to Play
The board is a square of numbered tiles with one gap. Any tile next to the gap can slide into it, and the gap moves to where the tile was. Your goal is to put the numbers in order, reading left to right and top to bottom, with the gap in the bottom-right corner.
Tap or click a tile to slide it; if it's further along the gap's row or column, every tile between them slides too. You can also swipe toward the gap, or use the arrow keys or W, A, S and D: Left slides the tile on the gap's right into it.
Rules
- A tile can only move into the gap, along its row or column.
- Every tile that moves counts as one move, so sliding three tiles at once is three moves.
- Every shuffle can be solved, and none starts already solved.
- The clock starts when you press Start and stops when the last tile lands.
- The Daily Challenge is a 4×4, the same for everyone. Your first solve of the day counts, ranked by fewest moves, with the faster time breaking a tie.
Tips & Strategy
Solve the top row first, then forget it
Finish the first row and leave it alone; the rest becomes a smaller puzzle. On bigger boards do the left column next, until a 3×3 corner is left. Tiles are tinted by their home row, so you can spot them at a glance.
Park the last two tiles of a row
The end of a row is the tricky part. Bring the last tile under its spot, put the one before it in the corner, then slide the pair in together.
Steer the gap, not the tile
A tile only moves when the gap reaches it. Plan where the gap goes, and walk it around placed tiles rather than through them.
FAQ
Can every puzzle really be solved?
Yes. Half of all layouts can never be solved, so each shuffle is checked with a parity rule first, and an unsolvable one is fixed by swapping two tiles.
Why did one tap add several moves?
Sliding a tile from further along the line moves every tile between it and the gap, and each tile that moves counts. The total is the same however you slide them.
Is there an undo button?
No. Sliding a tile back is the undo, and it costs a move like any other. If a game gets away from you, Same shuffle again restarts it from the beginning.
How is the Daily Challenge checked?
Your moves and their times are sent to our server, which deals the day's puzzle again, replays every move and counts them itself. A new puzzle arrives at midnight UTC.