Asterisk Sudoku

Asterisk Sudoku adds a ninth region shaped like a star. Nine specially marked cells, arranged in an asterisk around the centre of the grid, must also contain the digits 1–9 exactly once — on top of the usual rows, columns and boxes. It is a fixed-shape cousin of Hyper Sudoku, with one scattered star instead of four windows.

The rule: the star is a tenth unit

Treat the nine shaded asterisk cells as an extra region: together they must hold 1–9 with no repeats. The shaded cells below form the star.

How to use the star

Because the asterisk cells sit one per box (they never share a box), the star ties all nine boxes together — a digit placed in one asterisk cell is barred from the other eight. Scan the star like any unit: if eight of its cells are known, the ninth is forced, and any digit crowded across several boxes is quickly pinned to its one remaining star cell.

Solving strategy

• Treat the star as a region. Hunt hidden singles within it exactly as you would in a box.
• Use its long reach. The star spans all nine boxes, so it links distant cells the ordinary rules keep apart.
• Finish near-full stars. Eight known asterisk cells give the ninth for free.
• Feed the grid. Each star digit placed behaves like a given for its row, column and box.

Common mistakes

• Forgetting the star is a full unit. All nine asterisk cells need 1–9, not merely "no repeats with their boxes".
• Misplacing the cells. The asterisk sits in a fixed star around the centre — check which cells are marked.
• Scanning the star in isolation. Its power is where it overlaps the boxes and lines.
• Dropping the ordinary rules. Rows, columns and boxes still apply on top of the star.

Can I play it here?

Not yet — Asterisk Sudoku isn't one of the puzzle types SudokuStreak generates for now. But you can learn its rules above, and there's plenty here to sink your teeth into meanwhile:

• Browse all the Sudoku variants we do offer.
• Or print free puzzles from the printable PDF page.