Expert Star Battle answer — September 16, 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. Clump analysis (Region 1): candidate clumps can only just supply the remaining stars (row 4, column 2).
3. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 9, column 4).
4. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 9, column 2).
5. Triple analysis (Region 1 + Region 9 + Column 1): every legal combination of their stars rules these cells out (row 9, column 3).
6. Deep 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).
7. Deep lookahead: Placing star here leads to contradiction - stars at R5C5 and R6C4 would touch (row 3, column 5).
8. Deep lookahead: Placing star here leads to contradiction - stars at R1C9 and R1C10 would touch (row 4, column 4).
9. Deep lookahead: Placing star here leads to contradiction - stars at R3C9 and R4C10 would touch (row 5, column 2).
10. Triple analysis (Region 1 + Region 9 + Column 1): every legal combination of their stars rules these cells out (row 5, column 4).
11. Deep lookahead: Placing star here leads to contradiction - Region 9 would only have room for 0 of the 1 star it still needs (row 6, column 5).
12. Deep lookahead: Placing star here leads to contradiction - rows 8-10 can only hold 6 stars but the regions there would be forced to place 7 (row 6, column 9).
13. Deep lookahead: Placing star here leads to contradiction - Column 3 would end up with more than 2 stars (row 7, column 1).
14. Deep lookahead: Placing star here leads to contradiction - Row 9 would only have room for 0 of the 1 star it still needs (row 3, column 3).
15. Deep lookahead: Placing star here leads to contradiction - stars at R5C5 and R6C4 would touch (row 2, column 5).
16. Lookahead: Placing star here leads to contradiction - row 1 can only hold 2 stars but the regions there would be forced to place 3 (row 3, column 9).
17. Deep lookahead: Placing star here leads to contradiction - stars at R8C6 and R9C6 would touch (row 1, column 5).
18. Joint analysis (Region 5 + Column 5): every legal combination of their stars rules these cells out (row 9, column 6).
19. Deep lookahead: Placing star here leads to contradiction - Region 2 would end up with more than 2 stars (row 1, column 7).
20. Deep lookahead: Placing star here leads to contradiction - Row 5 would only have room for 0 of the 1 star it still needs (row 2, column 7).
21. Deep lookahead: Placing star here leads to contradiction - Row 9 would only have room for 0 of the 1 star it still needs (row 6, column 8).
22. Deep lookahead: Placing star here leads to contradiction - Column 6 would only have room for 1 of the 2 stars it still needs (row 7, column 7).
23. Deep lookahead: Placing star here leads to contradiction - column 3 can only hold 2 stars but the regions there would be forced to place 3 (row 8, column 3).
24. Deep lookahead: Placing star here leads to contradiction - stars at R5C7 and R6C7 would touch (row 8, column 8).
25. Deep lookahead: Placing star here leads to contradiction - rows 8-10 can only hold 6 stars but the regions there would be forced to place 7 (row 8, column 9).
26. Deep lookahead: Placing star here leads to contradiction - Region 9 would only have room for 0 of the 1 star it still needs (row 10, column 4).
27. Deep lookahead: Placing star here leads to contradiction - Row 2 would only have room for 0 of the 1 star it still needs (row 9, column 10).
28. Deep lookahead: Placing star here leads to contradiction - stars at R7C9 and R8C10 would touch (row 5, column 8).
29. Deep lookahead: Placing star here leads to contradiction - Region 7 would end up with more than 2 stars (row 2, column 9).
30. Deep lookahead: Placing star here leads to contradiction - Row 8 would only have room for 0 of the 1 star it still needs (row 3, column 2).
31. Deep lookahead: Placing star here leads to contradiction - Row 9 would only have room for 1 of the 2 stars it still needs (row 3, column 4).
32. Crowding (Column 4): a star here would leave too little room for its 2 remaining stars (row 7, column 3).
33. Composite container (columns 4-10): Regions 2, 5, 6, 7 and 10 are confined here, so the leftover cells owe exactly 4 of the band's 14 stars - a star on these cells would crowd them out (row 4, column 6).
34. Triple analysis (Region 1 + Region 3 + Column 1): every legal combination of their stars rules these cells out (row 1, column 3).
35. Deep lookahead: Placing star here leads to contradiction - Row 2 would only have room for 0 of the 1 star it still needs (row 1, column 1).
36. Deep lookahead: Placing star here leads to contradiction - Column 7 would end up with more than 2 stars (row 1, column 4).
37. Three candidates with two adjacent: Isolated candidate must hold a star (row 3, column 7).
38. Mark 6 cells adjacent to stars as X (row 2, column 6).
39. Region completion: 1 star needed, 1 candidate (row 1, column 6).
40. Squeeze (rows 2-3): the band's clumps can only just fit its stars (row 1, column 2).
41. Clump analysis (Region 3): each clump must supply its full share of stars (row 2, column 4).
42. Squeeze (columns 8-9): the band's clumps can only just fit its stars (row 4, column 10).
43. Lookahead: Placing star here leads to contradiction - column 10 can only hold 2 stars but the regions there would be forced to place 3 (row 10, column 10).
44. Crowding (Column 10): a star here would leave too little room for its 2 remaining stars (row 7, column 9).
45. Squeeze (columns 8-9): each clump in the band must supply its full share of stars (row 7, column 8).
46. Mark 2 cells adjacent to stars as X (row 6, column 7).
47. 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 5).
48. Crowding (Row 9): a star here would leave too little room for its 2 remaining stars (row 10, column 8).
49. Lookahead: Placing star here leads to contradiction - Region 7 would end up with more than 2 stars (row 10, column 9).
50. Lookahead: This cell must be a star - eliminating it leads to contradiction (Region 5 would only have room for 0 of the 1 star it still needs) (row 10, column 5).
51. Mark 1 cell adjacent to stars as X (row 10, column 6).
52. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 10, column 7).
53. Deep lookahead: Placing star here leads to contradiction - stars at R6C1 and R7C2 would touch (row 1, column 9).
54. Row completion: 1 star needed, 1 candidate (row 1, column 8).
55. Column 8 complete: Mark 1 remaining cell as X (row 9, column 8).
56. Region completion: 1 star needed, 1 candidate (row 9, column 7).
57. Mark 1 cell adjacent to stars as X (row 8, column 6).
58. Column 7 complete: Mark 1 remaining cell as X (row 5, column 7).
59. Two-option rule: Cell adjacent to both candidates (row 7, column 4).
60. Clump analysis (Column 9): candidate clumps can only just supply the remaining stars (row 9, column 1).
61. Row completion: 1 star needed, 1 candidate (row 9, column 9).
62. Mark 1 cell adjacent to stars as X (row 8, column 10).
63. Clump analysis (Row 8): candidate clumps can only just supply the remaining stars (row 7, column 2).
64. Three candidates with two adjacent: Isolated candidate must hold a star (row 6, column 3).
65. Mark 2 cells adjacent to stars as X (row 5, column 3).
66. Region completion: 1 star needed, 1 candidate (row 5, column 5).
67. Mark 3 cells adjacent to stars as X (row 4, column 5).
68. Region completion: 2 stars needed, 2 candidates (row 4, column 9).
69. Mark 2 cells adjacent to stars as X (row 3, column 10).
70. Region completion: 1 star needed, 1 candidate (row 2, column 10).
71. Region completion: 1 star needed, 1 candidate (row 7, column 6).
72. Mark 1 cell adjacent to stars as X (row 8, column 5).
73. Region completion: 1 star needed, 1 candidate (row 8, column 4).
74. Row 2 complete: Mark 2 remaining cells as X (row 2, column 1).
75. Region completion: 1 star needed, 1 candidate (row 3, column 1).
76. Row completion: 1 star needed, 1 candidate (row 4, column 3).
77. Row completion: 1 star needed, 1 candidate (row 5, column 1).
78. Mark 1 cell adjacent to stars as X (row 6, column 1).
79. Row completion: 1 star needed, 1 candidate (row 6, column 10).
80. Mark 1 cell adjacent to stars as X (row 7, column 10).
81. Column 1 complete: Mark 2 remaining cells as X (row 8, column 1).
82. Row completion: 1 star needed, 1 candidate (row 8, column 2).
83. Column completion: 1 star needed, 1 candidate (row 10, column 2).
84. Mark 1 cell adjacent to stars as X (row 10, column 3).
85. Solved! Every row, column, and region has its two stars, none touching.