Expert Star Battle answer — September 30, 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 2).
3. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 4, column 3).
4. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 5, column 2).
5. Joint analysis (Region 6 + Row 9): every legal combination of their stars rules these cells out (row 9, column 8).
6. Triple analysis (Region 9 + Region 4 + Column 1): every legal combination of their stars rules these cells out (row 4, column 2).
7. Deep lookahead: Placing star here leads to contradiction - Column 3 would only have room for 0 of the 1 star it still needs (row 2, column 3).
8. Deep lookahead: Placing star here leads to contradiction - stars at R9C3 and R10C3 would touch (row 2, column 4).
9. Deep lookahead: Placing star here leads to contradiction - Row 10 would only have room for 1 of the 2 stars it still needs (row 2, column 5).
10. Region confined to column: Eliminate other column candidates (row 6, column 4).
11. Region confined to column: Eliminate other column candidates (row 7, column 4).
12. Region confined to column: Eliminate other column candidates (row 8, column 4).
13. Region confined to column: Eliminate other column candidates (row 9, column 4).
14. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 8, column 6).
15. Region confined to column: Eliminate other column candidates (row 10, column 4).
16. Deep lookahead: Placing star here leads to contradiction - Column 7 would end up with more than 2 stars (row 3, column 2).
17. Deep lookahead: Placing star here leads to contradiction - stars at R10C7 and R10C8 would touch (row 3, column 6).
18. Deep lookahead: Placing star here leads to contradiction - Row 7 would only have room for 0 of the 1 star it still needs (row 3, column 7).
19. Deep lookahead: Placing star here leads to contradiction - Column 3 would only have room for 0 of the 1 star it still needs (row 3, column 9).
20. Deep lookahead: Placing star here leads to contradiction - Column 3 would only have room for 0 of the 1 star it still needs (row 3, column 10).
21. Deep lookahead: Placing star here leads to contradiction - Region 4 would only have room for 0 of the 1 star it still needs (row 4, column 4).
22. Deep lookahead: Placing star here leads to contradiction - Column 7 would end up with more than 2 stars (row 5, column 3).
23. Triple analysis (Row 4 + Row 5 + Region 5): every legal combination of their stars rules these cells out (row 6, column 5).
24. Deep lookahead: Placing star here leads to contradiction - stars at R5C5 and R6C6 would touch (row 2, column 8).
25. Deep lookahead: Placing star here leads to contradiction - stars at R5C5 and R6C6 would touch (row 2, column 10).
26. Deep lookahead: Placing star here leads to contradiction - Row 2 would only have room for 1 of the 2 stars it still needs (row 1, column 5).
27. Deep lookahead: Placing star here leads to contradiction - Region 4 would end up with more than 2 stars (row 1, column 8).
28. Composite container (columns 1-8): Regions 1, 4, 5, 6, 7 and 9 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 7, column 7).
29. Quad analysis (Region 10 + Row 4 + Region 3 + Column 8): every legal combination of their stars rules these cells out (row 7, column 9).
30. Deep lookahead: Placing star here leads to contradiction - columns 2-3 must hold 4 stars but the regions there could only supply 3 (row 1, column 3).
31. Squeeze (rows 1-2): each clump in the band must supply its full share of stars (row 1, column 4).
32. Deep lookahead: Placing star here leads to contradiction - stars at R2C9 and R3C8 would touch (row 2, column 6).
33. Crowding (Row 2): a star here would leave too little room for its 2 remaining stars (row 3, column 8).
34. Crowding (Region 10): a star here would leave too little room for its 2 remaining stars (row 4, column 6).
35. Composite container (columns 1-8): Regions 1, 4, 5, 6, 7 and 9 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 5, column 7).
36. Deep lookahead: Placing star here leads to contradiction - stars at R9C3 and R10C3 would touch (row 3, column 1).
37. Three candidates in a row: Middle cell can't hold a star (row 3, column 4).
38. Region completion: 1 star needed, 1 candidate (row 5, column 4).
39. Mark 2 cells adjacent to stars as X (row 5, column 5).
40. Row completion: 2 stars needed, 2 candidates (row 3, column 3).
41. Row completion: 1 star needed, 1 candidate (row 3, column 5).
42. Lookahead: Placing star here leads to contradiction - Region 6 would only have room for 1 of the 2 stars it still needs (row 10, column 5).
43. Deep lookahead: Placing star here leads to contradiction - stars at R7C6 and R8C7 would touch (row 4, column 8).
44. Crowding (Column 8): a star here would leave too little room for its 2 remaining stars (row 9, column 7).
45. Lookahead: Placing star here leads to contradiction - column 8 must hold 2 stars but the regions there could only supply 1 (row 10, column 9).
46. Quad analysis (Column 5 + Region 6 + Region 5 + Row 7): every legal combination of their stars rules these cells out (row 8, column 7).
47. Triple analysis (Region 3 + Region 8 + Column 10): every legal combination of their stars rules these cells out (row 4, column 10).
48. Region completion: 1 star needed, 1 candidate (row 4, column 7).
49. Mark 1 cell adjacent to stars as X (row 5, column 6).
50. Composite container (columns 8-10): Regions 3 and 8 are confined here, so the leftover cells owe exactly 2 of the band's 6 stars - a star on these cells would crowd them out (row 10, column 7).
51. Clump analysis (Region 6): each clump must supply its full share of stars (row 10, column 8).
52. Squeeze (columns 6-7): the band's clumps can only just fit its stars (row 9, column 5).
53. Two last candidates (column 5): Eliminate 1 cell adjacent to both (row 7, column 6).
54. Triple analysis (Region 5 + Region 8 + Row 7): every legal combination of their stars rules these cells out (row 8, column 9).
55. Crowding (Column 9): a star here would leave too little room for its 2 remaining stars (row 5, column 10).
56. Joint analysis (Row 5 + Region 5): every legal combination of their stars rules these cells out (row 6, column 8).
57. Deep lookahead: Placing star here leads to contradiction - Row 9 would only have room for 1 of the 2 stars it still needs (row 1, column 1).
58. Deep lookahead: Placing star here leads to contradiction - Row 9 would only have room for 1 of the 2 stars it still needs (row 1, column 7).
59. Deep lookahead: Placing star here leads to contradiction - Row 9 would only have room for 1 of the 2 stars it still needs (row 1, column 9).
60. Deep lookahead: Placing star here leads to contradiction - Region 3 would end up with more than 2 stars (row 1, column 10).
61. Three candidates with two adjacent: Isolated candidate must hold a star (row 2, column 9).
62. Squeeze (rows 4-5): the band's clumps can only just fit its stars (row 6, column 9).
63. Deep lookahead: Placing star here leads to contradiction - Column 3 would only have room for 0 of the 1 star it still needs (row 4, column 9).
64. Row completion: 1 star needed, 1 candidate (row 4, column 1).
65. Mark 1 cell adjacent to stars as X (row 5, column 1).
66. Row completion: 1 star needed, 1 candidate (row 5, column 9).
67. Mark 1 cell adjacent to stars as X (row 6, column 10).
68. Region completion: 1 star needed, 1 candidate (row 7, column 10).
69. Mark 1 cell adjacent to stars as X (row 8, column 10).
70. Clump analysis (Row 6): candidate clumps can only just supply the remaining stars (row 7, column 1).
71. Region confined to column: Eliminate other column candidates (row 2, column 1).
72. Region completion: 1 star needed, 1 candidate (row 1, column 2).
73. Row 1 complete: Mark 1 remaining cells as X (row 1, column 6).
74. Region completion: 1 star needed, 1 candidate (row 2, column 7).
75. Column 7 complete: Mark 1 remaining cells as X (row 6, column 7).
76. Three candidates with two adjacent: Isolated candidate must hold a star (row 6, column 2).
77. Mark 2 cells adjacent to stars as X (row 6, column 1).
78. Region completion: 1 star needed, 1 candidate (row 8, column 1).
79. Mark 3 cells adjacent to stars as X (row 8, column 2).
80. Row completion: 1 star needed, 1 candidate (row 6, column 6).
81. Mark 1 cell adjacent to stars as X (row 7, column 5).
82. Row completion: 1 star needed, 1 candidate (row 7, column 8).
83. Mark 1 cell adjacent to stars as X (row 8, column 8).
84. Column 1 complete: Mark 1 remaining cells as X (row 10, column 1).
85. Column 2 complete: Mark 1 remaining cells as X (row 10, column 2).
86. Column completion: 1 star needed, 1 candidate (row 8, column 5).
87. Mark 1 cell adjacent to stars as X (row 9, column 6).
88. Row 8 complete: Mark 1 remaining cells as X (row 8, column 3).
89. Row completion: 2 stars needed, 2 candidates (row 9, column 3).
90. Mark 1 cell adjacent to stars as X (row 10, column 3).
91. Region completion: 1 star needed, 1 candidate (row 10, column 6).
92. Row completion: 1 star needed, 1 candidate (row 9, column 10).
93. Mark 1 cell adjacent to stars as X (row 10, column 10).
94. Solved! Every row, column, and region has its two stars, none touching.