How to play
- Goal
- Cover the whole board with non-overlapping squares; every printed number equals its square's side length, and four different squares never meet at one point.
- How it ends
- The chart is won when every cell belongs to a valid square; 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 a grid-aligned square; a number gives its square’s side length, never its area.
- A square may hold zero, one or several clues. All clues in the same square must equal its side length.
- Four different squares cannot meet at one point. T junctions and equal-size neighbours are allowed.
- Tap opposite corners or drag to draw a square. Tap the same cell twice for a one-cell square. Erase removes a whole square; Undo repairs a placement.
Controls
| Mouse / touch | Choose opposite corners or drag between them; tap the same cell twice for a one-cell square |
|---|---|
| Arrows + Enter / Space | Move the cursor and choose or confirm a corner |
| Delete | Erase the whole square under the cursor |
| Z / Y | Undo / Redo |
| Escape | Cancel a draft, close a dialog or return to the atlas |
| Controller | D-pad moves; A chooses or confirms; X erases; B cancels or returns; shoulders Undo/Redo; Start tools; Back rules |
Tips for Square Jam
- Count the side A 3×3 square needs clues of 3, not 9. Every clue inside must match.
- Keep blank candidates An unnumbered square is legal and may be necessary to cover the floor.
- Inspect meeting points Three regions may meet at a T junction; four separate squares may not.
Questions about this game
Must every square contain a number?
No. Squares may contain no clue, one clue or several equal clues.
Can neighbouring squares have equal sizes?
Yes. Their side lengths may be equal; only a four-square meeting point is forbidden.
Can a square contain different numbers?
No. Every printed number inside equals that square’s side length.
Can replay improve my first time?
No. Your first completed time is retained; replay is practice.
All 24 charts are open. Progress and the original clock survive reload; a resumed completed time is saved only in this browser. Every chart includes an unnumbered square and repeated matching clues.
Watch how to play
About Square Jam
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