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