Expert Star Battle answer — June 27, 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 2).
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 3).
4. 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).
5. Clump analysis (Region 3): candidate clumps can only just supply the remaining stars (row 2, column 6).
6. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 7, column 2).
7. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 4, column 4).
8. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 7, column 6).
9. 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 6).
10. Three candidates with two adjacent: Isolated candidate must hold a star (row 4, column 7).
11. Mark 2 cells adjacent to stars as X (row 3, column 7).
12. Region completion: 1 star needed, 1 candidate (row 2, column 7).
13. Mark 4 cells adjacent to stars as X (row 1, column 6).
14. Column 7 complete: Mark 4 remaining cells as X (row 6, column 7).
15. 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 5).
16. Clump analysis (Region 9): each clump must supply its full share of stars (row 6, column 8).
17. Mark 3 cells adjacent to stars as X (row 5, column 9).
18. Clump analysis (Column 8): candidate clumps can only just supply the remaining stars (row 9, column 9).
19. Crowding (Column 6): a star here would leave too little room for its 2 remaining stars (row 7, column 5).
20. Two-option rule: Cell adjacent to both candidates (row 5, column 5).
21. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 3, column 4).
22. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 6, column 1).
23. Generalized counting (rows 8-10): region star limits exclude these cells (row 8, column 1).
24. Generalized counting (columns 8-10): region star limits exclude these cells (row 8, column 6).
25. Clump analysis (Column 6): candidate clumps can only just supply the remaining stars (row 10, column 5).
26. Region completion: 1 star needed, 1 candidate (row 6, column 6).
27. Composite container (columns 8-10): Regions 1 and 2 are confined here, so the leftover cells owe exactly 1 of the band's 6 stars - a star on these cells would crowd them out (row 2, column 9).
28. Composite container (rows 3-7): Regions 1 and 4 are confined here, so the leftover cells owe exactly 3 of the band's 10 stars - a star on these cells would crowd them out (row 2, column 1).
29. Composite container (rows 3-7): Regions 1 and 4 are confined here, so the leftover cells owe exactly 3 of the band's 10 stars - impossible without stars on these cells (row 3, column 1).
30. Joint analysis (Row 4 + Region 7): every legal combination of their stars rules these cells out (row 4, column 3).
31. Generalized counting (rows 1-2): region star limits exclude these cells (row 2, column 5).
32. Joint analysis (Row 7 + Row 8): every legal combination of their stars rules these cells out (row 8, column 9).
33. Joint analysis (Row 7 + Region 6): every legal combination of their stars rules these cells out (row 8, column 4).
34. Joint analysis (Row 7 + Row 8): every legal combination of their stars includes these cells (row 7, column 10).
35. Joint analysis (Row 8 + Row 9): every legal combination of their stars rules these cells out (row 10, column 8).
36. Deep lookahead: Placing star here leads to contradiction - stars at R2C3 and R3C3 would touch (row 1, column 1).
37. Two-option rule: Cell adjacent to both candidates (row 2, column 3).
38. Triple analysis (Row 2 + Row 3 + Column 9): every legal combination of their stars rules these cells out (row 4, column 10).
39. Generalized counting (rows 3-4): region star limits exclude these cells (row 3, column 3).
40. Deep lookahead: Placing star here leads to contradiction - Row 9 would only have room for 1 of the 2 stars it still needs (row 1, column 4).
41. Triple analysis (Column 5 + Region 10 + Column 4): every legal combination of their stars rules these cells out (row 10, column 3).
42. Three candidates with two adjacent: Isolated candidate must hold a star (row 10, column 2).
43. Composite container (columns 3-6): Regions 7 and 10 are confined here, so the leftover cells owe exactly 3 of the band's 8 stars - a star on these cells would crowd them out (row 1, column 2).
44. Region completion: 1 star needed, 1 candidate (row 1, column 3).
45. Row completion: 1 star needed, 1 candidate (row 2, column 10).
46. Mark 4 cells adjacent to stars as X (row 1, column 9).
47. Region completion: 1 star needed, 1 candidate (row 4, column 9).
48. Region completion: 1 star needed, 1 candidate (row 1, column 5).
49. Row completion: 1 star needed, 1 candidate (row 3, column 5).
50. Mark 1 cell adjacent to stars as X (row 4, column 5).
51. Column 5 complete: Mark 1 remaining cell as X (row 8, column 5).
52. Column completion: 1 star needed, 1 candidate (row 10, column 9).
53. Mark 3 cells adjacent to stars as X (row 9, column 8).
54. Region completion: 1 star needed, 1 candidate (row 8, column 8).
55. Row completion: 2 stars needed, 2 candidates (row 9, column 4).
56. Mark 2 cells adjacent to stars as X (row 8, column 3).
57. Region completion: 1 star needed, 1 candidate (row 8, column 2).
58. Mark 1 cell adjacent to stars as X (row 7, column 1).
59. Row completion: 1 star needed, 1 candidate (row 7, column 4).
60. Row completion: 1 star needed, 1 candidate (row 9, column 6).
61. Mark 1 cell adjacent to stars as X (row 10, column 6).
62. Column completion: 1 star needed, 1 candidate (row 5, column 1).
63. Mark 1 cell adjacent to stars as X (row 5, column 2).
64. Column completion: 1 star needed, 1 candidate (row 5, column 3).
65. Mark 1 cell adjacent to stars as X (row 5, column 4).
66. Solved! Every row, column, and region has its two stars, none touching.