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