Hard Star Battle answer — November 21, 2025

Full written solution

Every deduction from the walkthrough above, in order. Each technique is explained in the Star Battle strategy guide.

1. Starting position — the grid is split into regions (bold outlines). Each row, column, and region needs exactly two stars, and no two stars may touch.
2. 3-cell region rule: Middle cell can't hold a star (row 4, column 9).
3. Region completion: 2 stars needed, 2 candidates (row 3, column 9).
4. Mark 4 cells adjacent to stars as X (row 2, column 8).
5. Region completion: 1 star needed, 1 candidate (row 5, column 9).
6. Mark 3 cells adjacent to stars as X (row 5, column 8).
7. Column 9 complete: Mark 4 remaining cells as X (row 1, column 9).
8. Region completion: 2 stars needed, 2 candidates (row 7, column 8).
9. Mark 4 cells adjacent to stars as X (row 6, column 7).
10. Region completion: 1 star needed, 1 candidate (row 9, column 8).
11. Mark 1 cell adjacent to stars as X (row 9, column 7).
12. Column 8 complete: Mark 1 remaining cell as X (row 1, column 8).
13. 3-cell region rule: Middle cell can't hold a star (row 1, column 4).
14. Region completion: 2 stars needed, 2 candidates (row 1, column 3).
15. Mark 4 cells adjacent to stars as X (row 1, column 2).
16. Region completion: 1 star needed, 1 candidate (row 1, column 5).
17. Mark 3 cells adjacent to stars as X (row 1, column 6).
18. Row 1 complete: Mark 2 remaining cells as X (row 1, column 1).
19. Row completion: 2 stars needed, 2 candidates (row 2, column 1).
20. Mark 2 cells adjacent to stars as X (row 3, column 1).
21. Row completion: 1 star needed, 1 candidate (row 2, column 7).
22. Mark 2 cells adjacent to stars as X (row 3, column 6).
23. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 4, column 4).
24. Two last candidates (column 7): Eliminate 2 cells adjacent to both (row 4, column 6).
25. Clump analysis (Column 6): candidate clumps can only just supply the remaining stars (row 6, column 5).
26. Clump analysis (Region 3): candidate clumps can only just supply the remaining stars (row 4, column 3).
27. Region completion: 1 star needed, 1 candidate (row 4, column 7).
28. Mark 1 cell adjacent to stars as X (row 5, column 7).
29. Three candidates with two adjacent: Isolated candidate must hold a star (row 9, column 6).
30. Mark 1 cell adjacent to stars as X (row 8, column 6).
31. Row 9 complete: Mark 4 remaining cells as X (row 9, column 1).
32. Clump analysis (Row 8): candidate clumps can only just supply the remaining stars (row 7, column 1).
33. Row completion: 1 star needed, 1 candidate (row 7, column 6).
34. Mark 1 cell adjacent to stars as X (row 6, column 6).
35. Clump analysis (Row 6): candidate clumps can only just supply the remaining stars (row 5, column 1).
36. Row completion: 1 star needed, 1 candidate (row 5, column 5).
37. Mark 2 cells adjacent to stars as X (row 4, column 5).
38. Column completion: 2 stars needed, 2 candidates (row 3, column 4).
39. Mark 1 cell adjacent to stars as X (row 3, column 3).
40. Column completion: 1 star needed, 1 candidate (row 8, column 4).
41. Mark 1 cell adjacent to stars as X (row 8, column 3).
42. Column completion: 1 star needed, 1 candidate (row 6, column 3).
43. Mark 1 cell adjacent to stars as X (row 6, column 2).
44. Region completion: 1 star needed, 1 candidate (row 6, column 1).
45. Column 1 complete: Mark 2 remaining cells as X (row 4, column 1).
46. Region completion: 1 star needed, 1 candidate (row 4, column 2).
47. Region completion: 1 star needed, 1 candidate (row 8, column 2).
48. Solved! Every row, column, and region has its two stars, none touching.