Expert Star Battle answer — July 29, 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 5, column 4).
3. Blocking rule: This position would block too many candidates (row 5, column 5).
4. Three candidates with two adjacent: Isolated candidate must hold a star (row 4, column 4).
5. Mark 6 cells adjacent to stars as X (row 3, column 3).
6. Two-option rule: Cell adjacent to both candidates (row 7, column 4).
7. Two-option rule: Cell adjacent to both candidates (row 7, column 5).
8. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 8, column 7).
9. Clump analysis (Region 8): candidate clumps can only just supply the remaining stars (row 1, column 4).
10. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 1, column 9).
11. Crowding (Region 3): a star here would leave too little room for its 2 remaining stars (row 2, column 7).
12. Composite container (columns 1-3): Region 5 is confined here, so the leftover cells owe exactly 4 of the band's 6 stars - a star on these cells would crowd them out (row 9, column 2).
13. Triple analysis (Region 10 + Region 1 + Row 6): every legal combination of their stars rules these cells out (row 6, column 8).
14. Triple analysis (Column 1 + Column 2 + Region 5): every legal combination of their stars rules these cells out (row 7, column 3).
15. Deep lookahead: Placing star here leads to contradiction - Column 3 would only have room for 0 of the 1 star it still needs (row 1, column 2).
16. Deep lookahead: Placing star here leads to contradiction - stars at R9C1 and R10C1 would touch (row 1, column 6).
17. 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 2).
18. Deep lookahead: Placing star here leads to contradiction - stars at R9C1 and R10C1 would touch (row 2, column 4).
19. Three candidates with two adjacent: Isolated candidate must hold a star (row 2, column 5).
20. Mark 2 cells adjacent to stars as X (row 2, column 6).
21. Deep lookahead: Placing star here leads to contradiction - Row 2 would only have room for 0 of the 1 star it still needs (row 4, column 7).
22. Deep lookahead: Placing star here leads to contradiction - Row 6 would only have room for 1 of the 2 stars it still needs (row 4, column 8).
23. Composite container (columns 1-8): Regions 2, 3, 5, 6, 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).
24. Joint analysis (Column 7 + Column 6): every legal combination of their stars rules these cells out (row 2, column 8).
25. Deep lookahead: Placing star here leads to contradiction - columns 9-10 can only hold 4 stars but the regions there would be forced to place 5 (row 5, column 7).
26. Deep lookahead: Placing star here leads to contradiction - Region 6 would only have room for 0 of the 1 star it still needs (row 5, column 9).
27. Quad analysis (Region 7 + Column 9 + Row 7 + Region 1): every legal combination of their stars rules these cells out (row 10, column 8).
28. Deep lookahead: Placing star here leads to contradiction - stars at R9C7 and R10C7 would touch (row 5, column 10).
29. Joint analysis (Region 10 + Row 5): every legal combination of their stars rules these cells out (row 6, column 3).
30. Crowding (Column 3): a star here would leave too little room for its 2 remaining stars (row 9, column 4).
31. Deep lookahead: Placing star here leads to contradiction - stars at R8C6 and R9C7 would touch (row 6, column 5).
32. Region completion: 1 star needed, 1 candidate (row 6, column 4).
33. Column 4 complete: Mark 2 remaining cells as X (row 8, column 4).
34. Clump analysis (Column 5): candidate clumps can only just supply the remaining stars (row 9, column 6).
35. Triple analysis (Region 7 + Row 9 + Region 6): every legal combination of their stars rules these cells out (row 9, column 9).
36. Deep lookahead: Placing star here leads to contradiction - stars at R6C6 and R7C6 would touch (row 3, column 7).
37. Composite container (columns 1-8): Regions 2, 3, 5, 6 and 8 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 9).
38. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 8).
39. Generalized counting (rows 4-5): region star limits exclude these cells (row 4, column 10).
40. Blocking rule: This position would block too many candidates (row 2, column 10).
41. Three candidates with two adjacent: Isolated candidate must hold a star (row 1, column 10).
42. Two last candidates (row 2): Eliminate 1 cell adjacent to both (row 3, column 2).
43. Joint analysis (Column 7 + Column 6): every legal combination of their stars rules these cells out (row 1, column 8).
44. Row completion: 1 star needed, 1 candidate (row 1, column 7).
45. Quad analysis (Column 7 + Column 8 + Row 9 + Region 6): every legal combination of their stars rules these cells out (row 8, column 6).
46. 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 1).
47. Row completion: 1 star needed, 1 candidate (row 2, column 3).
48. Region complete: Mark 1 remaining cells as X (row 3, column 8).
49. Clump analysis (Row 3): each clump must supply its full share of stars (row 3, column 1).
50. Mark 1 cell adjacent to stars as X (row 4, column 2).
51. Region completion: 1 star needed, 1 candidate (row 5, column 2).
52. Mark 2 cells adjacent to stars as X (row 6, column 1).
53. Row completion: 1 star needed, 1 candidate (row 4, column 6).
54. Mark 1 cell adjacent to stars as X (row 5, column 6).
55. Clump analysis (Column 8): candidate clumps can only just supply the remaining stars (row 8, column 9).
56. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 8, column 2).
57. Squeeze (columns 8-9): the band's clumps can only just fit its stars (row 3, column 10).
58. Region completion: 1 star needed, 1 candidate (row 3, column 9).
59. 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 1).
60. Quad analysis (Row 6 + Column 10 + Region 1 + Row 7): every legal combination of their stars rules these cells out (row 8, column 10).
61. Squeeze (rows 8-9): the band's clumps can only just fit its stars (row 7, column 1).
62. Three candidates with two adjacent: Isolated candidate must hold a star (row 8, column 3).
63. Mark 2 cells adjacent to stars as X (row 7, column 2).
64. Region completion: 1 star needed, 1 candidate (row 8, column 1).
65. Mark 1 cell adjacent to stars as X (row 9, column 1).
66. Region completion: 1 star needed, 1 candidate (row 10, column 2).
67. Row 8 complete: Mark 2 remaining cells as X (row 8, column 5).
68. Column completion: 1 star needed, 1 candidate (row 9, column 5).
69. Mark 1 cell adjacent to stars as X (row 10, column 6).
70. Two last candidates (row 9): Eliminate 1 cell adjacent to both (row 10, column 7).
71. Region completion: 1 star needed, 1 candidate (row 7, column 6).
72. Mark 2 cells adjacent to stars as X (row 6, column 6).
73. Row completion: 1 star needed, 1 candidate (row 6, column 10).
74. Mark 2 cells adjacent to stars as X (row 7, column 9).
75. Region completion: 1 star needed, 1 candidate (row 7, column 8).
76. Column completion: 1 star needed, 1 candidate (row 9, column 7).
77. Mark 1 cell adjacent to stars as X (row 9, column 8).
78. Column completion: 1 star needed, 1 candidate (row 10, column 9).
79. Mark 1 cell adjacent to stars as X (row 10, column 10).
80. Solved! Every row, column, and region has its two stars, none touching.