PLAYING GUIDE
Plan the blank as well as the tile
Only a tile directly above, below, left or right of the blank can move into it. The goal is ascending reading order with the blank last. To bring a tile closer to its destination, first decide where the blank needs to stand.
Build a stable section
Solve one part of the board, then route other tiles through the remaining space. Repeatedly breaking a completed area creates more work. A useful practice is to finish the top row, then reduce the unsolved area while keeping that row intact.
Use cycles to move around a block
When a wanted tile cannot move directly toward its position, move nearby tiles around a small loop. This changes access without requiring an illegal diagonal slide. Take several planned moves at a time, checking the result before starting another loop.
A scramble is not a dead end
This implementation scrambles by legal moves from the solved board. It does not create an arbitrary tile arrangement that might be unreachable. If stuck, restart the same board to test another sequence before asking for a new scramble.
Updated 26 September 2026 · Our editorial method