Expert Star Battle answer — October 22, 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 2, column 2).
3. Clump analysis (Region 10): candidate clumps can only just supply the remaining stars (row 2, column 5).
4. Composite container (columns 4-10): Regions 1, 3, 5, 6, 9 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 6, column 4).
5. Composite container (columns 5-10): Regions 1, 3, 5 and 6 are confined here, so the leftover cells owe exactly 4 of the band's 12 stars - a star on these cells would crowd them out (row 4, column 6).
6. Lookahead: Placing star here leads to contradiction - columns 1-3 can only hold 6 stars but the regions there would be forced to place 7 (row 10, column 4).
7. Joint analysis (Region 10 + Region 1): every legal combination of their stars rules these cells out (row 2, column 7).
8. Joint analysis (Region 7 + Region 10): every legal combination of their stars rules these cells out (row 3, column 3).
9. Triple analysis (Region 7 + Region 4 + Column 1): every legal combination of their stars rules these cells out (row 8, column 1).
10. Triple analysis (Region 8 + Region 4 + Column 2): every legal combination of their stars rules these cells out (row 6, column 2).
11. Deep lookahead: Placing star here leads to contradiction - stars at R9C7 and R10C7 would touch (row 1, column 4).
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 3, column 5).
13. Triple analysis (Region 10 + Column 5 + Column 6): every legal combination of their stars rules these cells out (row 4, column 7).
14. Quad analysis (Region 10 + Column 5 + Column 6 + Region 6): every legal combination of their stars rules these cells out (row 3, column 7).
15. Deep lookahead: Placing star here leads to contradiction - stars at R8C4 and R9C4 would touch (row 2, column 3).
16. Deep lookahead: Placing star here leads to contradiction - stars at R4C4 and R5C5 would touch (row 2, column 6).
17. 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 3, column 1).
18. Joint analysis (Region 7 + Row 2): every legal combination of their stars rules these cells out (row 1, column 9).
19. Triple analysis (Region 4 + Column 3 + Region 2): every legal combination of their stars rules these cells out (row 5, column 2).
20. Triple analysis (Region 10 + Region 7 + Region 8): every legal combination of their stars includes these cells (row 3, column 6).
21. Deep lookahead: Placing star here leads to contradiction - column 3 can only hold 2 stars but the regions there would be forced to place 3 (row 2, column 10).
22. Squeeze (rows 1-2): the band's clumps can only just fit its stars (row 3, column 8).
23. Joint analysis (Row 2 + Region 7): every legal combination of their stars rules these cells out (row 1, column 8).
24. Deep lookahead: Placing star here leads to contradiction - column 3 can only hold 2 stars but the regions there would be forced to place 3 (row 3, column 10).
25. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 5, column 9).
26. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 5, column 10).
27. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 7, column 9).
28. 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 9).
29. Squeeze (rows 2-3): the band's clumps can only just fit its stars (row 4, column 4).
30. Deep lookahead: Placing star here leads to contradiction - Column 7 would only have room for 1 of the 2 stars it still needs (row 6, column 3).
31. Deep lookahead: Placing star here leads to contradiction - stars at R5C1 and R6C1 would touch (row 7, column 3).
32. Composite container (columns 1-3): Regions 4 and 7 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 9, column 2).
33. Lookahead: Placing star here leads to contradiction - row 5 can only hold 2 stars but the regions there would be forced to place 3 (row 5, column 1).
34. Triple analysis (Region 4 + Region 7 + Column 1): every legal combination of their stars rules these cells out (row 7, column 1).
35. Triple analysis (Region 4 + Region 7 + Column 2): every legal combination of their stars rules these cells out (row 1, column 2).
36. Composite container (rows 4-9): Regions 4, 5, 6 and 8 are confined here, so the leftover cells owe exactly 4 of the band's 12 stars - a star on these cells would crowd them out (row 7, column 5).
37. Composite container (rows 7-10): Regions 2, 3 and 9 are confined here, so the leftover cells owe exactly 2 of the band's 8 stars - a star on these cells would crowd them out (row 6, column 7).
38. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 9, column 5).
39. Joint analysis (Row 9 + Region 9): every legal combination of their stars rules these cells out (row 8, column 9).
40. Crowding (Column 9): a star here would leave too little room for its 2 remaining stars (row 5, column 8).
41. Clump analysis (Row 5): candidate clumps can only just supply the remaining stars (row 6, column 6).
42. Joint analysis (Column 6 + Region 9): every legal combination of their stars rules these cells out (row 10, column 6).
43. Lookahead: Placing star here leads to contradiction - stars at R9C4 and R10C5 would touch (row 8, column 10).
44. Star claim: Region 3 must place a star in column 8; cells touching all its options are eliminated (row 9, column 7).
45. Squeeze (rows 7-8): the band's clumps can only just fit its stars (row 7, column 7).
46. Fish: stars of columns 3,5,7 are confined to rows 1,5,10, claiming all their stars (row 1, column 1).
47. Three candidates with two adjacent: Isolated candidate must hold a star (row 9, column 10).
48. Three candidates with two adjacent: Isolated candidate must hold a star (row 1, column 3).
49. Mark 1 cell adjacent to stars as X (row 2, column 4).
50. Region completion: 1 star needed, 1 candidate (row 3, column 4).
51. Row 3 complete: Mark 1 remaining cell as X (row 3, column 2).
52. Region completion: 1 star needed, 1 candidate (row 2, column 1).
53. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 5).
54. Clump analysis (Column 2): candidate clumps can only just supply the remaining stars (row 5, column 3).
55. Region completion: 1 star needed, 1 candidate (row 4, column 2).
56. Mark 1 cell adjacent to stars as X (row 4, column 1).
57. Row completion: 1 star needed, 1 candidate (row 5, column 7).
58. Mark 2 cells adjacent to stars as X (row 4, column 8).
59. Column completion: 1 star needed, 1 candidate (row 6, column 1).
60. Mark 1 cell adjacent to stars as X (row 7, column 2).
61. Region completion: 1 star needed, 1 candidate (row 8, column 2).
62. Column completion: 1 star needed, 1 candidate (row 10, column 3).
63. Mark 1 cell adjacent to stars as X (row 9, column 4).
64. Row completion: 1 star needed, 1 candidate (row 9, column 8).
65. Mark 2 cells adjacent to stars as X (row 8, column 8).
66. Region completion: 2 stars needed, 2 candidates (row 8, column 6).
67. Mark 1 cell adjacent to stars as X (row 7, column 6).
68. Region completion: 1 star needed, 1 candidate (row 7, column 8).
69. Mark 1 cell adjacent to stars as X (row 6, column 9).
70. Region completion: 1 star needed, 1 candidate (row 10, column 5).
71. Row completion: 1 star needed, 1 candidate (row 6, column 10).
72. Row completion: 1 star needed, 1 candidate (row 7, column 4).
73. Mark 1 cell adjacent to stars as X (row 8, column 4).
74. Column 5 complete: Mark 1 remaining cell as X (row 1, column 5).
75. Row completion: 1 star needed, 1 candidate (row 1, column 7).
76. Mark 1 cell adjacent to stars as X (row 2, column 8).
77. Region completion: 1 star needed, 1 candidate (row 2, column 9).
78. Column completion: 1 star needed, 1 candidate (row 4, column 9).
79. Mark 1 cell adjacent to stars as X (row 4, column 10).
80. Solved! Every row, column, and region has its two stars, none touching.