How to play
- Goal
- Divide the whole board into rectangles, each containing exactly one number equal to the difference between its width and height.
- How it ends
- The chart is won when every cell belongs to a valid rectangle; erase and Undo repair placements without losing progress.
- Record
- Your first unassisted solve of each chart is kept in this browser; verified solves under twenty-four hours compete for fastest-time records. Replays are practice.
- Cover every cell with non-overlapping rectangles or squares.
- Each rectangle contains exactly one clue, equal to the absolute difference between its width and height in cells.
- Zero means a square; a clue is not the area. Select opposite corners or drag to place a rectangle.
- Erase and Undo repair a placement. Your first clock starts on opening; Restart keeps it running, and replay is practice.
Controls
| Mouse / touch | Select two opposite corners, or drag between them; select a single cell twice |
|---|---|
| Arrows + Enter / Space | Move the cursor and choose or confirm a corner |
| Delete | Erase the selected rectangle |
| Z / Y | Undo / Redo |
| Escape | Cancel a draft, close a dialog or return to the atlas |
| Controller | D-pad moves; A chooses corners or confirms; X erases; B cancels or returns; shoulders Undo/Redo; Start tools; Back rules |
Tips for Sashikaku
- Subtract the side lengths A 2 × 3 rectangle needs a clue of 1; its area of 6 is irrelevant.
- Zero makes a square A zero may belong to a 1 × 1 square or a larger square.
- Use neighbouring clues A rectangle can never include two printed numbers, even when they agree.
Questions about this game
Can a rectangle have no number?
No. Every rectangle contains exactly one clue.
Does zero mean an empty cell?
No. Zero is a square clue. Blank cells have no clue.
Can equal rectangles touch?
Yes. There is no restriction on equal neighbours or four-way corners.
Can replay improve my first time?
No. Your first completed time is retained; replay is untimed practice.
All charts are open. Progress saves in this browser; a reloaded attempt finishes locally on its original clock.
Watch how to play
About Sashikaku
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