Solving tips

Most boards open up once you know where to look.

1. Start with the smallest regions

A region with a single cell is a free stamp. A region with two cells is almost as good: whichever cell is wrong gets ruled out as soon as another stamp lands nearby.

2. A region stuck in one line owns that line

If every open cell of a region sits in the same row, its stamp must be in that row. No other region can put a stamp there, so you can mark the rest of the row. The same works for columns.

3. Count squeezed groups

If two regions can only use the same two rows between them, those rows are spoken for. Any other cell in those rows is out. Three regions inside three rows works the same way. This is the idea behind most hard boards.

4. Work it backwards too

If the open cells of a row all belong to one region, that region's stamp must be in that row, so the region's cells elsewhere are out.

5. Any 2×2 block holds at most one stamp

Two stamps can't touch, so a 2×2 square can never contain more than one. Corners and thin regions hide useful consequences of this.

6. Mark as you go

Use × marks for cells you have ruled out. The dots the game draws show what your stamps already block, but your own marks track the deductions the game can't see for you.

7. Don't guess

Every board has one solution reachable by reasoning. If you feel stuck, re-scan each row, column and region for a spot with only one option left. Still stuck? Open that level's guide.