Hard Star Battle answer — September 18, 2026

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. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 8, column 2).
3. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 9, column 2).
4. Three candidates with two adjacent: Isolated candidate must hold a star (row 9, column 3).
5. Mark 3 cells adjacent to stars as X (row 8, column 3).
6. Clump analysis (Region 2): candidate clumps can only just supply the remaining stars (row 8, column 5).
7. Clump analysis (Region 2): each clump must supply its full share of stars (row 7, column 4).
8. Mark 5 cells adjacent to stars as X (row 6, column 3).
9. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 7, column 7).
10. Clump analysis (Region 4): candidate clumps can only just supply the remaining stars (row 3, column 8).
11. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 6, column 7).
12. 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 8).
13. Clump analysis (Region 8): candidate clumps can only just supply the remaining stars (row 4, column 1).
14. Generalized counting (columns 9-9): region star limits exclude these cells (row 1, column 9).
15. Composite container (rows 1-5): Regions 1, 3, 4 and 7 are confined here, so the leftover cells owe exactly 2 of the band's 10 stars - a star on these cells would crowd them out (row 4, column 9).
16. Three candidates with two adjacent: Isolated candidate must hold a star (row 3, column 9).
17. Mark 1 cell adjacent to stars as X (row 2, column 8).
18. Two-option rule: Cell adjacent to both candidates (row 4, column 6).
19. Two-option rule: Cell adjacent to both candidates (row 5, column 6).
20. Clump analysis (Row 6): candidate clumps can only just supply the remaining stars (row 5, column 1).
21. Three candidates with two adjacent: Isolated candidate must hold a star (row 4, column 2).
22. Mark 5 cells adjacent to stars as X (row 3, column 1).
23. Two last candidates (column 3): Eliminate 4 cells adjacent to both (row 1, column 2).
24. Column completion: 1 star needed, 1 candidate (row 6, column 2).
25. Mark 1 cell adjacent to stars as X (row 6, column 1).
26. Row completion: 1 star needed, 1 candidate (row 6, column 6).
27. Mark 3 cells adjacent to stars as X (row 5, column 5).
28. Region completion: 1 star needed, 1 candidate (row 4, column 7).
29. Mark 2 cells adjacent to stars as X (row 3, column 6).
30. Row 4 complete: Mark 2 remaining cells as X (row 4, column 4).
31. Region completion: 2 stars needed, 2 candidates (row 2, column 7).
32. Mark 4 cells adjacent to stars as X (row 1, column 6).
33. Region completion: 1 star needed, 1 candidate (row 3, column 5).
34. Mark 2 cells adjacent to stars as X (row 2, column 5).
35. Region completion: 2 stars needed, 2 candidates (row 1, column 5).
36. Region completion: 1 star needed, 1 candidate (row 2, column 3).
37. Mark 1 cell adjacent to stars as X (row 1, column 3).
38. Row completion: 1 star needed, 1 candidate (row 1, column 1).
39. Mark 1 cell adjacent to stars as X (row 2, column 1).
40. Region completion: 1 star needed, 1 candidate (row 5, column 4).
41. Row completion: 1 star needed, 1 candidate (row 5, column 9).
42. Column 5 complete: Mark 1 remaining cell as X (row 9, column 5).
43. Column 7 complete: Mark 2 remaining cells as X (row 8, column 7).
44. Region completion: 1 star needed, 1 candidate (row 7, column 8).
45. Mark 3 cells adjacent to stars as X (row 7, column 9).
46. Row completion: 2 stars needed, 2 candidates (row 8, column 1).
47. Mark 1 cell adjacent to stars as X (row 9, column 1).
48. Row completion: 1 star needed, 1 candidate (row 8, column 6).
49. Mark 1 cell adjacent to stars as X (row 9, column 6).
50. Column completion: 1 star needed, 1 candidate (row 9, column 8).
51. Mark 1 cell adjacent to stars as X (row 9, column 9).
52. Solved! Every row, column, and region has its two stars, none touching.