Expert Star Battle answer — September 19, 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 7).
3. Clump analysis (Region 2): candidate clumps can only just supply the remaining stars (row 5, column 4).
4. Clump analysis (Region 4): candidate clumps can only just supply the remaining stars (row 4, column 2).
5. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 9, column 5).
6. Crowding (Region 7): a star here would leave too little room for its 2 remaining stars (row 2, column 6).
7. 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 3).
8. Deep 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 1, column 2).
9. Deep lookahead: Placing star here leads to contradiction - stars at R3C7 and R3C8 would touch (row 1, column 4).
10. Deep lookahead: Placing star here leads to contradiction - Row 3 would only have room for 0 of the 1 star it still needs (row 1, column 5).
11. Deep lookahead: Placing star here leads to contradiction - Row 3 would only have room for 0 of the 1 star it still needs (row 2, column 5).
12. Deep lookahead: Placing star here leads to contradiction - stars at R8C3 and R9C4 would touch (row 1, column 3).
13. Deep lookahead: Placing star here leads to contradiction - Row 10 would end up with more than 2 stars (row 1, column 7).
14. Deep lookahead: Placing star here leads to contradiction - stars at R5C1 and R6C1 would touch (row 3, column 2).
15. 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 3, column 6).
16. Composite container (columns 6-10): Regions 5, 7, 8 and 10 are confined here, so the leftover cells owe exactly 2 of the band's 10 stars - a star on these cells would crowd them out (row 5, column 7).
17. Deep lookahead: Placing star here leads to contradiction - Region 8 would only have room for 1 of the 2 stars it still needs (row 6, column 1).
18. 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 6).
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 4).
20. Deep lookahead: Placing star here leads to contradiction - Row 3 would only have room for 0 of the 1 star it still needs (row 7, column 6).
21. Deep lookahead: Placing star here leads to contradiction - stars at R1C8 and R2C9 would touch (row 8, column 3).
22. Deep lookahead: Placing star here leads to contradiction - Column 2 would only have room for 0 of the 1 star it still needs (row 8, column 8).
23. Deep lookahead: Placing star here leads to contradiction - Row 8 would only have room for 0 of the 1 star it still needs (row 7, column 2).
24. Triple analysis (Region 4 + Region 9 + Column 1): every legal combination of their stars rules these cells out (row 5, column 3).
25. Generalized counting (columns 1-3): region star limits exclude these cells (row 2, column 4).
26. Joint analysis (Column 4 + Column 5): every legal combination of their stars rules these cells out (row 9, column 4).
27. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 10, column 1).
28. Blocking rule: This position would block too many candidates (row 8, column 2).
29. Triple analysis (Region 2 + Row 7 + Region 5): every legal combination of their stars rules these cells out (row 8, column 9).
30. Triple analysis (Region 4 + Region 3 + Column 1): every legal combination of their stars rules these cells out (row 2, column 1).
31. Clump analysis (Row 2): candidate clumps can only just supply the remaining stars (row 3, column 3).
32. Clump analysis (Region 8): candidate clumps can only just supply the remaining stars (row 5, column 9).
33. Joint analysis (Row 5 + Region 1): every legal combination of their stars rules these cells out (row 6, column 5).
34. Joint analysis (Column 4 + Column 5): every legal combination of their stars rules these cells out (row 7, column 3).
35. Squeeze (columns 2-3): the band's clumps can only just fit its stars (row 5, column 2).
36. Row completion: 2 stars needed, 2 candidates (row 1, column 6).
37. Row completion: 1 star needed, 1 candidate (row 1, column 8).
38. Mark 1 cell adjacent to stars as X (row 2, column 9).
39. Region complete: Mark 1 remaining cells as X (row 3, column 7).
40. Three candidates with two adjacent: Isolated candidate must hold a star (row 2, column 10).
41. Three candidates with two adjacent: Isolated candidate must hold a star (row 4, column 3).
42. Clump analysis (Region 8): candidate clumps can only just supply the remaining stars (row 4, column 1).
43. Clump analysis (Region 1): each clump must supply its full share of stars (row 3, column 5).
44. Crowding (Column 4): a star here would leave too little room for its 2 remaining stars (row 9, column 3).
45. Blocking rule: This position would block too many candidates (row 8, column 1).
46. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 1).
47. Mark 1 cell adjacent to stars as X (row 6, column 2).
48. Column completion: 2 stars needed, 2 candidates (row 2, column 2).
49. Mark 2 cells adjacent to stars as X (row 2, column 3).
50. Region completion: 2 stars needed, 2 candidates (row 5, column 1).
51. Region completion: 1 star needed, 1 candidate (row 6, column 3).
52. Mark 1 cell adjacent to stars as X (row 6, column 4).
53. Row completion: 1 star needed, 1 candidate (row 3, column 8).
54. Mark 1 cell adjacent to stars as X (row 4, column 9).
55. Region completion: 1 star needed, 1 candidate (row 4, column 10).
56. Column 1 complete: Mark 1 remaining cells as X (row 9, column 1).
57. Region completion: 1 star needed, 1 candidate (row 9, column 2).
58. Column completion: 2 stars needed, 2 candidates (row 8, column 4).
59. Mark 1 cell adjacent to stars as X (row 8, column 5).
60. Region completion: 1 star needed, 1 candidate (row 5, column 5).
61. Mark 2 cells adjacent to stars as X (row 5, column 6).
62. Region completion: 1 star needed, 1 candidate (row 6, column 7).
63. Mark 4 cells adjacent to stars as X (row 5, column 8).
64. Row 6 complete: Mark 2 remaining cells as X (row 6, column 9).
65. Region completion: 1 star needed, 1 candidate (row 8, column 7).
66. Mark 2 cells adjacent to stars as X (row 8, column 6).
67. Row 8 complete: Mark 1 remaining cells as X (row 8, column 10).
68. Column completion: 1 star needed, 1 candidate (row 10, column 4).
69. Mark 1 cell adjacent to stars as X (row 10, column 5).
70. Column completion: 1 star needed, 1 candidate (row 10, column 6).
71. Mark 1 cell adjacent to stars as X (row 10, column 7).
72. Column completion: 2 stars needed, 2 candidates (row 7, column 9).
73. Mark 1 cell adjacent to stars as X (row 7, column 10).
74. Column completion: 1 star needed, 1 candidate (row 9, column 9).
75. Mark 1 cell adjacent to stars as X (row 9, column 10).
76. Solved! Every row, column, and region has its two stars, none touching.