Expert Star Battle answer — October 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: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 9, column 1).
3. 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 2).
4. Three candidates with two adjacent: Isolated candidate must hold a star (row 8, column 1).
5. Mark 3 cells adjacent to stars as X (row 7, column 1).
6. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 2, column 7).
7. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 3, column 7).
8. Three candidates with two adjacent: Isolated candidate must hold a star (row 3, column 6).
9. Mark 6 cells adjacent to stars as X (row 2, column 5).
10. Two-option rule: Cell adjacent to both candidates (row 2, column 9).
11. Two-option rule: Cell adjacent to both candidates (row 3, column 9).
12. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 6, column 4).
13. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 6, column 5).
14. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 5).
15. Mark 6 cells adjacent to stars as X (row 6, column 6).
16. Two-option rule: Cell adjacent to both candidates (row 4, column 4).
17. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 2, column 2).
18. Joint analysis (Region 6 + Column 10): every legal combination of their stars rules these cells out (row 10, column 10).
19. Triple analysis (Region 8 + Region 6 + Column 10): every legal combination of their stars rules these cells out (row 8, column 9).
20. Triple analysis (Region 9 + Region 8 + Column 8): every legal combination of their stars rules these cells out (row 5, column 8).
21. Deep lookahead: Placing star here leads to contradiction - Region 10 would end up with more than 2 stars (row 1, column 9).
22. Quad analysis (Region 9 + Region 8 + Column 7 + Region 3): every legal combination of their stars rules these cells out (row 6, column 8).
23. Deep lookahead: Placing star here leads to contradiction - Region 7 would end up with more than 2 stars (row 1, column 7).
24. Deep lookahead: Placing star here leads to contradiction - stars at R6C9 and R6C10 would touch (row 2, column 3).
25. Quad analysis (Row 2 + Region 8 + Region 6 + Column 10): every legal combination of their stars rules these cells out (row 8, column 10).
26. Joint analysis (Column 9 + Region 6): every legal combination of their stars includes these cells (row 9, column 9).
27. Quad analysis (Row 8 + Row 7 + Column 7 + Region 3): every legal combination of their stars rules these cells out (row 9, column 6).
28. Deep lookahead: Placing star here leads to contradiction - stars at R8C3 and R9C4 would touch (row 1, column 1).
29. Deep lookahead: Placing star here leads to contradiction - Row 5 would only have room for 1 of the 2 stars it still needs (row 1, column 8).
30. Star claim: Region 8 must place a star in column 9; cells touching all its options are eliminated (row 5, column 10).
31. Generalized counting (columns 9-9): region star limits exclude these cells (row 7, column 9).
32. Triple analysis (Column 8 + Column 7 + Region 3): every legal combination of their stars rules these cells out (row 8, column 7).
33. Row completion: 1 star needed, 1 candidate (row 8, column 3).
34. Mark 3 cells adjacent to stars as X (row 7, column 3).
35. Joint analysis (Row 7 + Row 6): every legal combination of their stars rules these cells out (row 5, column 2).
36. Triple analysis (Column 9 + Row 7 + Column 8): every legal combination of their stars rules these cells out (row 7, column 10).
37. Joint analysis (Region 7 + Row 6): every legal combination of their stars rules these cells out (row 5, column 1).
38. Squeeze (columns 8-9): the band's clumps can only just fit its stars (row 3, column 8).
39. Region completion: 1 star needed, 1 candidate (row 2, column 8).
40. Deep lookahead: Placing star here leads to contradiction - Row 10 would only have room for 0 of the 1 star it still needs (row 1, column 3).
41. Deep lookahead: Placing star here leads to contradiction - Region 8 would only have room for 1 of the 2 stars it still needs (row 1, column 6).
42. Column completion: 1 star needed, 1 candidate (row 5, column 6).
43. Mark 2 cells adjacent to stars as X (row 5, column 5).
44. Region completion: 1 star needed, 1 candidate (row 5, column 4).
45. Mark 3 cells adjacent to stars as X (row 4, column 3).
46. Clump analysis (Column 7): candidate clumps can only just supply the remaining stars (row 7, column 8).
47. Row completion: 1 star needed, 1 candidate (row 7, column 7).
48. Column completion: 1 star needed, 1 candidate (row 4, column 8).
49. Mark 1 cell adjacent to stars as X (row 4, column 9).
50. Region complete: Mark 1 remaining cell as X (row 10, column 7).
51. Column completion: 1 star needed, 1 candidate (row 9, column 7).
52. Region complete: Mark 3 remaining cells as X (row 9, column 5).
53. Column completion: 1 star needed, 1 candidate (row 1, column 5).
54. Mark 1 cell adjacent to stars as X (row 1, column 4).
55. Column completion: 1 star needed, 1 candidate (row 3, column 4).
56. Mark 1 cell adjacent to stars as X (row 3, column 3).
57. Row 3 complete: Mark 3 remaining cells as X (row 3, column 1).
58. Column completion: 1 star needed, 1 candidate (row 10, column 3).
59. Mark 1 cell adjacent to stars as X (row 10, column 2).
60. Region completion: 1 star needed, 1 candidate (row 10, column 1).
61. Region complete: Mark 1 remaining cell as X (row 6, column 1).
62. Column 1 complete: Mark 2 remaining cells as X (row 2, column 1).
63. Region completion: 1 star needed, 1 candidate (row 1, column 2).
64. Row 1 complete: Mark 1 remaining cell as X (row 1, column 10).
65. Region completion: 2 stars needed, 2 candidates (row 2, column 10).
66. Region completion: 1 star needed, 1 candidate (row 6, column 9).
67. Mark 1 cell adjacent to stars as X (row 6, column 10).
68. Region completion: 1 star needed, 1 candidate (row 4, column 10).
69. Row 4 complete: Mark 1 remaining cell as X (row 4, column 2).
70. Region completion: 1 star needed, 1 candidate (row 6, column 2).
71. Solved! Every row, column, and region has its two stars, none touching.