Expert Star Battle answer — August 25, 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 3).
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 5, column 7).
4. 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 9).
5. Clump analysis (Region 2): candidate clumps can only just supply the remaining stars (row 9, column 3).
6. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 4, column 9).
7. Clump analysis (Region 8): candidate clumps can only just supply the remaining stars (row 4, column 6).
8. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 1, column 10).
9. Three candidates with two adjacent: Isolated candidate must hold a star (row 8, column 9).
10. Mark 4 cells adjacent to stars as X (row 7, column 8).
11. Three candidates in a column: Middle cell can't hold a star (row 5, column 10).
12. Region completion: 2 stars needed, 2 candidates (row 4, column 10).
13. Mark 1 cell adjacent to stars as X (row 3, column 9).
14. Region completion: 1 star needed, 1 candidate (row 6, column 10).
15. Generalized counting (rows 7-10): region star limits exclude these cells (row 4, column 5).
16. 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 6).
17. Generalized counting (columns 8-9): region star limits exclude these cells (row 1, column 8).
18. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 2, column 6).
19. Generalized counting (columns 7-9): region star limits exclude these cells (row 1, column 7).
20. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 2, column 3).
21. Composite container (columns 1-6): Regions 2, 3, 6, 7 and 9 are confined here, so the leftover cells owe exactly 2 of the band's 12 stars - a star on these cells would crowd them out (row 4, column 7).
22. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 6).
23. Composite container (rows 1-4): Regions 4, 6 and 9 are confined here, so the leftover cells owe exactly 1 of the band's 8 stars - a star on these cells would crowd them out (row 3, column 2).
24. Composite container (columns 1-7): Regions 1, 2, 3, 6, 7 and 9 are confined here, so the leftover cells owe exactly 1 of the band's 14 stars - a star on these cells would crowd them out (row 2, column 8).
25. Quad analysis (Region 2 + Column 5 + Row 7 + Region 7): every legal combination of their stars rules these cells out (row 2, column 4).
26. Joint analysis (Region 6 + Row 1): every legal combination of their stars rules these cells out (row 1, column 2).
27. Deep lookahead: Placing star here leads to contradiction - Region 2 would only have room for 1 of the 2 stars it still needs (row 1, column 4).
28. Clump analysis (Region 6): each clump must supply its full share of stars (row 1, column 3).
29. Mark 1 cell adjacent to stars as X (row 2, column 2).
30. Squeeze (columns 4-5): the band's clumps can only just fit its stars (row 1, column 6).
31. Quad analysis (Row 3 + Region 9 + Column 4 + Column 5): every legal combination of their stars rules these cells out (row 1, column 9).
32. Deep lookahead: Placing star here leads to contradiction - Row 3 would only have room for 0 of the 1 star it still needs (row 3, column 5).
33. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 4, column 3).
34. Squeeze (columns 4-5): the band's clumps can only just fit its stars (row 3, column 3).
35. Squeeze (rows 2-3): the band's clumps can only just fit its stars (row 4, column 8).
36. Region completion: 1 star needed, 1 candidate (row 10, column 8).
37. Mark 1 cell adjacent to stars as X (row 9, column 7).
38. Column completion: 1 star needed, 1 candidate (row 2, column 9).
39. 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 6).
40. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 5).
41. Mark 2 cells adjacent to stars as X (row 7, column 4).
42. Two last candidates (column 6): Eliminate 2 cells adjacent to both (row 9, column 5).
43. Clump analysis (Column 4): candidate clumps can only just supply the remaining stars (row 10, column 3).
44. Two last candidates (column 3): Eliminate 1 cell adjacent to both (row 6, column 2).
45. Squeeze (rows 3-4): the band's clumps can only just fit its stars (row 2, column 7).
46. Region completion: 1 star needed, 1 candidate (row 3, column 7).
47. Squeeze (rows 8-9): each clump in the band must supply its full share of stars (row 9, column 4).
48. Mark 1 cell adjacent to stars as X (row 10, column 4).
49. Squeeze (columns 2-3): the band's clumps can only just fit its stars (row 9, column 1).
50. Generalized counting (columns 1-1): region star limits exclude these cells (row 7, column 1).
51. Squeeze (rows 8-9): the band's clumps can only just fit its stars (row 7, column 3).
52. Column completion: 1 star needed, 1 candidate (row 5, column 3).
53. Mark 3 cells adjacent to stars as X (row 4, column 2).
54. Row completion: 1 star needed, 1 candidate (row 4, column 1).
55. Mark 2 cells adjacent to stars as X (row 3, column 1).
56. Region complete: Mark 1 remaining cell as X (row 6, column 1).
57. Row completion: 1 star needed, 1 candidate (row 3, column 4).
58. Mark 1 cell adjacent to stars as X (row 2, column 5).
59. Region completion: 1 star needed, 1 candidate (row 1, column 5).
60. Row 1 complete: Mark 1 remaining cell as X (row 1, column 1).
61. Region completion: 1 star needed, 1 candidate (row 2, column 1).
62. Row 5 complete: Mark 1 remaining cell as X (row 5, column 8).
63. Region completion: 1 star needed, 1 candidate (row 6, column 8).
64. Mark 1 cell adjacent to stars as X (row 7, column 7).
65. Region completion: 1 star needed, 1 candidate (row 8, column 7).
66. Mark 1 cell adjacent to stars as X (row 9, column 6).
67. Row completion: 1 star needed, 1 candidate (row 7, column 2).
68. Mark 1 cell adjacent to stars as X (row 8, column 2).
69. Region completion: 1 star needed, 1 candidate (row 9, column 2).
70. Mark 1 cell adjacent to stars as X (row 10, column 2).
71. Region completion: 1 star needed, 1 candidate (row 10, column 6).
72. Solved! Every row, column, and region has its two stars, none touching.