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