Expert Star Battle answer — July 18, 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 6): candidate clumps can only just supply the remaining stars (row 1, column 9).
3. Blocking rule: This position would block too many candidates (row 2, column 7).
4. Composite container (columns 1-7): Regions 1, 2, 3, 7, 8 and 10 are confined here, so the leftover cells owe exactly 2 of the band's 14 stars - a star on these cells would crowd them out (row 2, column 6).
5. Deep lookahead: Placing star here leads to contradiction - stars at R9C9 and R10C9 would touch (row 3, column 5).
6. Deep lookahead: Placing star here leads to contradiction - column 8 can only hold 2 stars but the regions there would be forced to place 3 (row 3, column 6).
7. Deep lookahead: Placing star here leads to contradiction - stars at R9C9 and R10C9 would touch (row 4, column 2).
8. Clump analysis (Region 10): candidate clumps can only just supply the remaining stars (row 5, column 4).
9. Deep lookahead: Placing star here leads to contradiction - column 8 can only hold 2 stars but the regions there would be forced to place 3 (row 4, column 8).
10. Clump analysis (Region 4): candidate clumps can only just supply the remaining stars (row 6, column 9).
11. Deep 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 5, column 2).
12. Deep lookahead: Placing star here leads to contradiction - stars at R9C9 and R10C9 would touch (row 6, column 1).
13. Deep lookahead: Placing star here leads to contradiction - Region 10 would end up with more than 2 stars (row 9, column 9).
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 2, column 2).
15. Deep lookahead: Placing star here leads to contradiction - Region 3 would only have room for 0 of the 1 star it still needs (row 2, column 8).
16. Triple analysis (Region 5 + Region 3 + Row 1): every legal combination of their stars rules these cells out (row 4, column 7).
17. Quad analysis (Row 2 + Column 2 + Region 3 + Column 3): every legal combination of their stars rules these cells out (row 1, column 4).
18. Deep lookahead: Placing star here leads to contradiction - Row 10 would only have room for 0 of the 1 star it still needs (row 3, column 3).
19. Deep lookahead: Placing star here leads to contradiction - Region 8 would only have room for 0 of the 1 star it still needs (row 1, column 6).
20. Deep lookahead: Placing star here leads to contradiction - Region 2 would end up with more than 2 stars (row 3, column 4).
21. Generalized counting (rows 1-2): region star limits exclude these cells (row 2, column 1).
22. Deep lookahead: Placing star here leads to contradiction - Row 9 would only have room for 0 of the 1 star it still needs (row 4, column 6).
23. Deep lookahead: Placing star here leads to contradiction - Region 4 would only have room for 1 of the 2 stars it still needs (row 5, column 5).
24. Deep lookahead: Placing star here leads to contradiction - Region 1 would only have room for 1 of the 2 stars it still needs (row 6, column 3).
25. Deep lookahead: Placing star here leads to contradiction - stars at R8C6 and R9C6 would touch (row 1, column 3).
26. Deep lookahead: Placing star here leads to contradiction - stars at R8C6 and R9C6 would touch (row 1, column 5).
27. Deep lookahead: Placing star here leads to contradiction - Region 4 would only have room for 1 of the 2 stars it still needs (row 6, column 5).
28. Deep lookahead: Placing star here leads to contradiction - row 4 can only hold 2 stars but the regions there would be forced to place 3 (row 6, column 6).
29. Squeeze (columns 5-6): each clump in the band must supply its full share of stars (row 2, column 5).
30. Mark 1 cell adjacent to stars as X (row 2, column 4).
31. Generalized counting (columns 7-10): region star limits exclude these cells (row 7, column 7).
32. Clump analysis (Region 1): candidate clumps can only just supply the remaining stars (row 8, column 5).
33. Quad analysis (Region 6 + Column 9 + Region 4 + Column 10): every legal combination of their stars rules these cells out (row 2, column 10).
34. Row completion: 1 star needed, 1 candidate (row 2, column 3).
35. Mark 2 cells adjacent to stars as X (row 1, column 2).
36. Region complete: Mark 1 remaining cells as X (row 1, column 1).
37. Three candidates with two adjacent: Isolated candidate must hold a star (row 1, column 10).
38. Clump analysis (Column 2): candidate clumps can only just supply the remaining stars (row 7, column 1).
39. Generalized counting (rows 3-3): region star limits exclude these cells (row 3, column 1).
40. Three candidates with two adjacent: Isolated candidate must hold a star (row 6, column 2).
41. Mark 3 cells adjacent to stars as X (row 5, column 1).
42. Region completion: 1 star needed, 1 candidate (row 4, column 1).
43. Two last candidates (column 1): Eliminate 1 cell adjacent to both (row 9, column 2).
44. Clump analysis (Row 4): each clump must supply its full share of stars (row 5, column 6).
45. Mark 3 cells adjacent to stars as X (row 4, column 5).
46. Column completion: 2 stars needed, 2 candidates (row 1, column 7).
47. Mark 1 cell adjacent to stars as X (row 1, column 8).
48. Column completion: 1 star needed, 1 candidate (row 3, column 7).
49. Mark 1 cell adjacent to stars as X (row 3, column 8).
50. Clump analysis (Region 2): candidate clumps can only just supply the remaining stars (row 8, column 4).
51. Squeeze (columns 4-5): the band's clumps can only just fit its stars (row 4, column 3).
52. Region completion: 1 star needed, 1 candidate (row 4, column 4).
53. Two last candidates (column 3): Eliminate 1 cell adjacent to both (row 9, column 4).
54. Clump analysis (Region 8): candidate clumps can only just supply the remaining stars (row 10, column 8).
55. Blocking rule: This position would block too many candidates (row 8, column 9).
56. Crowding (Column 9): a star here would leave too little room for its 2 remaining stars (row 6, column 8).
57. Row completion: 1 star needed, 1 candidate (row 6, column 4).
58. Mark 2 cells adjacent to stars as X (row 7, column 4).
59. Column 4 complete: Mark 1 remaining cells as X (row 10, column 4).
60. Three candidates with two adjacent: Isolated candidate must hold a star (row 8, column 3).
61. Mark 1 cell adjacent to stars as X (row 8, column 2).
62. Region completion: 1 star needed, 1 candidate (row 8, column 1).
63. Row 8 complete: Mark 3 remaining cells as X (row 8, column 6).
64. Column 1 complete: Mark 1 remaining cells as X (row 10, column 1).
65. Column completion: 1 star needed, 1 candidate (row 10, column 2).
66. Mark 1 cell adjacent to stars as X (row 10, column 3).
67. Two-option rule: Cell adjacent to both candidates (row 9, column 5).
68. Column completion: 1 star needed, 1 candidate (row 10, column 5).
69. Mark 2 cells adjacent to stars as X (row 9, column 6).
70. Region completion: 1 star needed, 1 candidate (row 7, column 6).
71. Row completion: 2 stars needed, 2 candidates (row 9, column 8).
72. Row completion: 1 star needed, 1 candidate (row 9, column 10).
73. Region complete: Mark 1 remaining cells as X (row 7, column 9).
74. Column completion: 2 stars needed, 2 candidates (row 3, column 9).
75. Mark 1 cell adjacent to stars as X (row 3, column 10).
76. Column completion: 1 star needed, 1 candidate (row 5, column 9).
77. Mark 2 cells adjacent to stars as X (row 5, column 8).
78. Column completion: 1 star needed, 1 candidate (row 7, column 8).
79. Region complete: Mark 1 remaining cells as X (row 7, column 10).
80. Solved! Every row, column, and region has its two stars, none touching.