Expert Star Battle answer — October 3, 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 1, column 9).
3. Blocking rule: This position would block too many candidates (row 2, column 9).
4. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 1, column 7).
5. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 9, column 9).
6. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 9, column 5).
7. Clump analysis (Region 10): candidate clumps can only just supply the remaining stars (row 2, column 2).
8. Generalized counting (columns 1-1): region star limits exclude these cells (row 9, column 1).
9. Composite container (rows 1-6): Regions 2, 3, 6, 8 and 10 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 5, column 2).
10. Composite container (columns 1-8): Regions 1, 3, 4, 5, 8 and 10 are confined here, so the leftover cells owe exactly 4 of the band's 16 stars - a star on these cells would crowd them out (row 6, column 7).
11. Lookahead: Placing star here leads to contradiction - column 1 can only hold 2 stars but the regions there would be forced to place 3 (row 2, column 3).
12. Lookahead: Placing star here leads to contradiction - column 1 can only hold 2 stars but the regions there would be forced to place 3 (row 3, column 3).
13. Composite container (rows 3-10): Regions 1, 2, 3, 4, 5, 7 and 9 are confined here, so the leftover cells owe exactly 2 of the band's 16 stars - a star on these cells would crowd them out (row 3, column 6).
14. Lookahead: Placing star here leads to contradiction - row 10 can only hold 2 stars but the regions there would be forced to place 3 (row 8, column 9).
15. Triple analysis (Region 9 + Region 5 + Row 10): every legal combination of their stars rules these cells out (row 8, column 7).
16. Quad analysis (Region 7 + Region 9 + Column 7 + Region 5): every legal combination of their stars rules these cells out (row 4, column 8).
17. Deep lookahead: Placing star here leads to contradiction - Region 8 would only have room for 1 of the 2 stars it still needs (row 1, column 1).
18. Clump analysis (Region 10): candidate clumps can only just supply the remaining stars (row 3, column 2).
19. Lookahead: Placing star here leads to contradiction - column 1 can only hold 2 stars but the regions there would be forced to place 3 (row 5, column 3).
20. Deep lookahead: Placing star here leads to contradiction - rows 5-6 must hold 4 stars but the regions there could only supply 3 (row 1, column 6).
21. Quad analysis (Region 7 + Column 7 + Column 6 + Row 7): every legal combination of their stars rules these cells out (row 7, column 5).
22. Deep lookahead: Placing star here leads to contradiction - row 5 must hold 2 stars but the regions there could only supply 1 (row 2, column 6).
23. Squeeze (columns 6-7): the band's clumps can only just fit its stars (row 3, column 8).
24. Deep lookahead: Placing star here leads to contradiction - stars at R9C8 and R10C7 would touch (row 1, column 10).
25. Three candidates with two adjacent: Isolated candidate must hold a star (row 2, column 10).
26. Mark 2 cells adjacent to stars as X (row 3, column 9).
27. Joint analysis (Column 10 + Region 9): every legal combination of their stars rules these cells out (row 9, column 8).
28. Generalized counting (rows 10-10): region star limits exclude these cells (row 10, column 2).
29. Lookahead: Placing star here leads to contradiction - row 10 can only hold 2 stars but the regions there would be forced to place 3 (row 10, column 10).
30. Triple analysis (Column 9 + Region 7 + Region 2): every legal combination of their stars rules these cells out (row 6, column 6).
31. Squeeze (columns 6-7): the band's clumps can only just fit its stars (row 4, column 7).
32. Region completion: 1 star needed, 1 candidate (row 1, column 8).
33. Clump analysis (Region 10): candidate clumps can only just supply the remaining stars (row 1, column 4).
34. Crowding (Region 8): a star here would leave too little room for its 2 remaining stars (row 3, column 4).
35. Squeeze (rows 2-3): the band's clumps can only just fit its stars (row 4, column 5).
36. Clump analysis (Region 8): each clump must supply its full share of stars (row 3, column 7).
37. Squeeze (columns 5-6): the band's clumps can only just fit its stars (row 2, column 4).
38. Generalized counting (columns 2-5): region star limits exclude these cells (row 5, column 6).
39. Clump analysis (Column 6): candidate clumps can only just supply the remaining stars (row 7, column 7).
40. Column completion: 1 star needed, 1 candidate (row 5, column 7).
41. Mark 1 cell adjacent to stars as X (row 5, column 8).
42. Clump analysis (Column 5): candidate clumps can only just supply the remaining stars (row 5, column 4).
43. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 4, column 10).
44. Clump analysis (Region 7): each clump must supply its full share of stars (row 7, column 6).
45. Mark 2 cells adjacent to stars as X (row 6, column 5).
46. Three candidates with two adjacent: Isolated candidate must hold a star (row 6, column 2).
47. Mark 6 cells adjacent to stars as X (row 5, column 1).
48. Row completion: 1 star needed, 1 candidate (row 6, column 9).
49. Mark 3 cells adjacent to stars as X (row 5, column 9).
50. Region complete: Mark 1 remaining cells as X (row 4, column 9).
51. Region completion: 1 star needed, 1 candidate (row 8, column 8).
52. Row completion: 1 star needed, 1 candidate (row 5, column 5).
53. Mark 1 cell adjacent to stars as X (row 4, column 4).
54. Row completion: 1 star needed, 1 candidate (row 7, column 4).
55. Mark 2 cells adjacent to stars as X (row 8, column 3).
56. Column 8 complete: Mark 1 remaining cells as X (row 10, column 8).
57. Column completion: 1 star needed, 1 candidate (row 10, column 9).
58. Mark 1 cell adjacent to stars as X (row 9, column 10).
59. Region completion: 1 star needed, 1 candidate (row 8, column 10).
60. Row 8 complete: Mark 2 remaining cells as X (row 8, column 1).
61. Three candidates in a row: Middle cell can't hold a star (row 4, column 2).
62. Region completion: 2 stars needed, 2 candidates (row 4, column 1).
63. Mark 1 cell adjacent to stars as X (row 3, column 1).
64. Region completion: 1 star needed, 1 candidate (row 4, column 3).
65. Row completion: 1 star needed, 1 candidate (row 3, column 5).
66. Mark 1 cell adjacent to stars as X (row 2, column 5).
67. Row completion: 1 star needed, 1 candidate (row 2, column 1).
68. Mark 1 cell adjacent to stars as X (row 1, column 2).
69. Region completion: 1 star needed, 1 candidate (row 1, column 3).
70. Column completion: 1 star needed, 1 candidate (row 9, column 2).
71. Mark 1 cell adjacent to stars as X (row 9, column 3).
72. Region complete: Mark 1 remaining cells as X (row 9, column 4).
73. Row completion: 1 star needed, 1 candidate (row 9, column 6).
74. Mark 1 cell adjacent to stars as X (row 10, column 6).
75. Region completion: 1 star needed, 1 candidate (row 10, column 4).
76. Solved! Every row, column, and region has its two stars, none touching.