Hard Star Battle answer — November 1, 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 9, column 7).
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 10, column 7).
4. Clump analysis (Region 1): candidate clumps can only just supply the remaining stars (row 9, column 5).
5. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 7, column 9).
6. Clump analysis (Region 8): candidate clumps can only just supply the remaining stars (row 3, column 9).
7. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 4, column 6).
8. Clump analysis (Region 10): candidate clumps can only just supply the remaining stars (row 2, column 7).
9. Undercounting: 6 regions fit in rows 1-6, eliminate 4 outside candidates (row 6, column 5).
10. Undercounting: 2 regions fit in cols 9-10, eliminate 4 outside candidates (row 1, column 9).
11. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 2, column 8).
12. Three candidates with two adjacent: Isolated candidate must hold a star (row 3, column 8).
13. Mark 4 cells adjacent to stars as X (row 3, column 7).
14. Clump analysis (Column 9): candidate clumps can only just supply the remaining stars (row 5, column 8).
15. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 5, column 6).
16. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 7).
17. Two-option rule: Cell adjacent to both candidates (row 4, column 4).
18. Two-option rule: Cell adjacent to both candidates (row 5, column 4).
19. Clump analysis (Column 9): each clump must supply its full share of stars (row 8, column 9).
20. Mark 6 cells adjacent to stars as X (row 7, column 8).
21. Region completion: 1 star needed, 1 candidate (row 10, column 10).
22. Three candidates with two adjacent: Isolated candidate must hold a star (row 10, column 8).
23. Row 10 complete: Mark 5 remaining cells as X (row 10, column 1).
24. Region completion: 1 star needed, 1 candidate (row 9, column 6).
25. Mark 3 cells adjacent to stars as X (row 8, column 5).
26. Column 8 complete: Mark 1 remaining cell as X (row 1, column 8).
27. Region completion: 1 star needed, 1 candidate (row 1, column 7).
28. Mark 2 cells adjacent to stars as X (row 1, column 6).
29. Column 7 complete: Mark 1 remaining cell as X (row 7, column 7).
30. 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 3).
31. 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 3).
32. Clump analysis (Row 2): candidate clumps can only just supply the remaining stars (row 1, column 2).
33. Clump analysis (Row 7): candidate clumps can only just supply the remaining stars (row 8, column 1).
34. Two last candidates (row 8): Eliminate 1 cell adjacent to both (row 7, column 3).
35. Clump analysis (Region 3): candidate clumps can only just supply the remaining stars (row 3, column 1).
36. Column completion: 1 star needed, 1 candidate (row 4, column 10).
37. Mark 1 cell adjacent to stars as X (row 5, column 9).
38. Region completion: 1 star needed, 1 candidate (row 6, column 9).
39. Squeeze (rows 1-2): the band's clumps can only just fit its stars (row 2, column 2).
40. Clump analysis (Column 1): candidate clumps can only just supply the remaining stars (row 6, column 2).
41. Clump analysis (Column 2): candidate clumps can only just supply the remaining stars (row 4, column 3).
42. Clump analysis (Column 4): candidate clumps can only just supply the remaining stars (row 6, column 3).
43. Three candidates in a column: Middle cell can't hold a star (row 2, column 3).
44. Row completion: 2 stars needed, 2 candidates (row 2, column 1).
45. Mark 1 cell adjacent to stars as X (row 1, column 1).
46. Region completion: 1 star needed, 1 candidate (row 1, column 3).
47. Row 1 complete: Mark 1 remaining cell as X (row 1, column 5).
48. Row completion: 1 star needed, 1 candidate (row 2, column 5).
49. Mark 2 cells adjacent to stars as X (row 3, column 5).
50. Region completion: 1 star needed, 1 candidate (row 3, column 3).
51. Mark 1 cell adjacent to stars as X (row 4, column 2).
52. Row completion: 1 star needed, 1 candidate (row 4, column 5).
53. Mark 1 cell adjacent to stars as X (row 5, column 5).
54. Row completion: 1 star needed, 1 candidate (row 5, column 2).
55. Mark 1 cell adjacent to stars as X (row 6, column 1).
56. Region completion: 1 star needed, 1 candidate (row 6, column 4).
57. Mark 1 cell adjacent to stars as X (row 7, column 4).
58. Region completion: 2 stars needed, 2 candidates (row 7, column 1).
59. Mark 1 cell adjacent to stars as X (row 8, column 2).
60. Region completion: 1 star needed, 1 candidate (row 7, column 6).
61. Row completion: 1 star needed, 1 candidate (row 8, column 4).
62. Mark 1 cell adjacent to stars as X (row 9, column 4).
63. Region completion: 1 star needed, 1 candidate (row 9, column 2).
64. Solved! Every row, column, and region has its two stars, none touching.