Hard Star Battle answer — August 10, 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: This position would block too many candidates (row 5, column 9).
3. Blocking rule: This position would block too many candidates (row 8, column 6).
4. Clump analysis (Region 1): candidate clumps can only just supply the remaining stars (row 9, column 5).
5. Blocking rule: This position would block too many candidates (row 7, column 6).
6. Three candidates with two adjacent: Isolated candidate must hold a star (row 8, column 7).
7. Mark 5 cells adjacent to stars as X (row 7, column 7).
8. Two-option rule: Cell adjacent to both candidates (row 7, column 4).
9. Two-option rule: Cell adjacent to both candidates (row 8, column 4).
10. Clump analysis (Region 1): candidate clumps can only just supply the remaining stars (row 10, column 1).
11. Blocking rule: This position would block too many candidates (row 8, column 2).
12. Blocking rule: This position would block too many candidates (row 8, column 3).
13. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 3).
14. Mark 4 cells adjacent to stars as X (row 6, column 2).
15. Clump analysis (Region 3): candidate clumps can only just supply the remaining stars (row 5, column 8).
16. Squeeze (columns 8-9): the band's clumps can only just fit its stars (row 8, column 10).
17. Undercounting: 7 regions fit in cols 4-10, eliminate 7 outside candidates (row 4, column 6).
18. Crowding (Row 5): a star here would leave too little room for its 2 remaining stars (row 4, column 2).
19. Crowding (Column 6): a star here would leave too little room for its 2 remaining stars (row 2, column 5).
20. Squeeze (rows 5-6): the band's clumps can only just fit its stars (row 5, column 2).
21. Region completion: 1 star needed, 1 candidate (row 9, column 2).
22. Row completion: 1 star needed, 1 candidate (row 9, column 9).
23. Mark 1 cell adjacent to stars as X (row 8, column 9).
24. Row completion: 1 star needed, 1 candidate (row 8, column 5).
25. Mark 1 cell adjacent to stars as X (row 7, column 5).
26. Row completion: 1 star needed, 1 candidate (row 7, column 10).
27. Mark 2 cells adjacent to stars as X (row 6, column 9).
28. Region complete: Mark 1 remaining cells as X (row 6, column 7).
29. Row completion: 2 stars needed, 2 candidates (row 6, column 1).
30. Mark 1 cell adjacent to stars as X (row 5, column 1).
31. Region completion: 1 star needed, 1 candidate (row 5, column 3).
32. Row completion: 1 star needed, 1 candidate (row 5, column 10).
33. Mark 2 cells adjacent to stars as X (row 4, column 9).
34. Region completion: 1 star needed, 1 candidate (row 6, column 8).
35. Column 10 complete: Mark 3 remaining cells as X (row 1, column 10).
36. Blocking rule: This position would block too many candidates (row 1, column 8).
37. Blocking rule: This position would block too many candidates (row 2, column 8).
38. Three candidates with two adjacent: Isolated candidate must hold a star (row 1, column 7).
39. Mark 2 cells adjacent to stars as X (row 1, column 6).
40. Column completion: 2 stars needed, 2 candidates (row 3, column 6).
41. Mark 4 cells adjacent to stars as X (row 3, column 5).
42. Row completion: 2 stars needed, 2 candidates (row 4, column 1).
43. Mark 2 cells adjacent to stars as X (row 3, column 1).
44. Row completion: 1 star needed, 1 candidate (row 4, column 8).
45. Mark 2 cells adjacent to stars as X (row 3, column 8).
46. Row completion: 1 star needed, 1 candidate (row 3, column 4).
47. Mark 1 cell adjacent to stars as X (row 2, column 4).
48. Column 1 complete: Mark 2 remaining cells as X (row 1, column 1).
49. Row completion: 2 stars needed, 2 candidates (row 2, column 2).
50. Mark 1 cell adjacent to stars as X (row 1, column 2).
51. Row completion: 1 star needed, 1 candidate (row 2, column 9).
52. Mark 1 cell adjacent to stars as X (row 1, column 9).
53. Column completion: 1 star needed, 1 candidate (row 10, column 6).
54. Mark 2 cells adjacent to stars as X (row 10, column 5).
55. Region completion: 1 star needed, 1 candidate (row 10, column 4).
56. Column 4 complete: Mark 1 remaining cells as X (row 1, column 4).
57. Region completion: 1 star needed, 1 candidate (row 1, column 5).
58. Solved! Every row, column, and region has its two stars, none touching.