Hard Star Battle answer — November 5, 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 8, column 3).
5. Mark 6 cells adjacent to stars as X (row 7, column 2).
6. 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 7).
7. Star claim: Region 9 must place a star in row 3; cells touching all its options are eliminated (row 4, column 7).
8. Crowding (Region 3): a star here would leave too little room for its 2 remaining stars (row 7, column 5).
9. Crowding (Region 9): a star here would leave too little room for its 2 remaining stars (row 2, column 6).
10. Undercounting: 2 regions fit in rows 9-10, eliminate 4 outside candidates (row 9, column 1).
11. Region completion: 1 star needed, 1 candidate (row 8, column 1).
12. Mark 1 cell adjacent to stars as X (row 7, column 1).
13. Row 8 complete: Mark 6 remaining cells as X (row 8, 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 5, column 4).
15. Three candidates with two adjacent: Isolated candidate must hold a star (row 6, column 4).
16. Mark 4 cells adjacent to stars as X (row 5, column 3).
17. Region completion: 1 star needed, 1 candidate (row 4, column 5).
18. Mark 6 cells adjacent to stars as X (row 3, column 4).
19. Three candidates with two adjacent: Isolated candidate must hold a star (row 1, column 7).
20. Mark 2 cells adjacent to stars as X (row 1, column 6).
21. Two-option rule: Cell adjacent to both candidates (row 4, column 8).
22. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 6, 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 6, column 7).
24. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 7).
25. Mark 2 cells adjacent to stars as X (row 5, column 8).
26. Column 7 complete: Mark 3 remaining cells as X (row 3, column 7).
27. Region completion: 1 star needed, 1 candidate (row 7, column 6).
28. Region completion: 1 star needed, 1 candidate (row 3, column 8).
29. Mark 3 cells adjacent to stars as X (row 2, column 9).
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 7, column 9).
31. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 8).
32. Mark 1 cell adjacent to stars as X (row 6, column 9).
33. Row 7 complete: Mark 1 remaining cell as X (row 7, column 10).
34. Region completion: 1 star needed, 1 candidate (row 6, column 10).
35. Mark 2 cells adjacent to stars as X (row 5, column 9).
36. Row 6 complete: Mark 2 remaining cells as X (row 6, column 1).
37. Column 8 complete: Mark 1 remaining cell as X (row 10, column 8).
38. Two last candidates (row 5): Eliminate 2 cells adjacent to both (row 4, column 1).
39. Two last candidates (column 6): Eliminate 2 cells adjacent to both (row 9, column 5).
40. Row completion: 2 stars needed, 2 candidates (row 9, column 6).
41. Mark 1 cell adjacent to stars as X (row 10, column 6).
42. Row completion: 1 star needed, 1 candidate (row 9, column 9).
43. Mark 2 cells adjacent to stars as X (row 10, column 9).
44. Region completion: 1 star needed, 1 candidate (row 10, column 4).
45. Mark 1 cell adjacent to stars as X (row 10, column 3).
46. Column 4 complete: Mark 2 remaining cells as X (row 1, column 4).
47. Column completion: 1 star needed, 1 candidate (row 1, column 9).
48. Mark 2 cells adjacent to stars as X (row 1, column 10).
49. Row 1 complete: Mark 4 remaining cells as X (row 1, column 1).
50. Column completion: 1 star needed, 1 candidate (row 2, column 5).
51. Clump analysis (Row 2): candidate clumps can only just supply the remaining stars (row 3, column 2).
52. Clump analysis (Column 3): candidate clumps can only just supply the remaining stars (row 5, column 2).
53. Row completion: 1 star needed, 1 candidate (row 5, column 1).
54. Column 1 complete: Mark 3 remaining cells as X (row 2, column 1).
55. Region completion: 1 star needed, 1 candidate (row 2, column 2).
56. Mark 2 cells adjacent to stars as X (row 2, column 3).
57. Region completion: 1 star needed, 1 candidate (row 4, column 3).
58. Region completion: 1 star needed, 1 candidate (row 10, column 2).
59. Row completion: 1 star needed, 1 candidate (row 3, column 10).
60. Mark 1 cell adjacent to stars as X (row 4, column 10).
61. Solved! Every row, column, and region has its two stars, none touching.