Expert Star Battle answer — December 9, 2025

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 4, column 7).
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 4, column 8).
4. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 8).
5. Mark 6 cells adjacent to stars as X (row 4, column 9).
6. Two-option rule: Cell adjacent to both candidates (row 2, column 7).
7. Two-option rule: Cell adjacent to both candidates (row 2, column 8).
8. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 8, column 9).
9. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 9).
10. Mark 2 cells adjacent to stars as X (row 7, column 8).
11. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 8, column 4).
12. Three candidates with two adjacent: Isolated candidate must hold a star (row 8, column 3).
13. Mark 7 cells adjacent to stars as X (row 7, column 2).
14. Two-option rule: Cell adjacent to both candidates (row 8, column 6).
15. Two-option rule: Cell adjacent to both candidates (row 9, column 6).
16. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 1, column 4).
17. 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 4).
18. Three candidates with two adjacent: Isolated candidate must hold a star (row 1, column 3).
19. Mark 3 cells adjacent to stars as X (row 1, column 2).
20. Column 3 complete: Mark 4 remaining cells as X (row 3, column 3).
21. Two-option rule: Cell adjacent to both candidates (row 1, column 6).
22. Two-option rule: Cell adjacent to both candidates (row 2, column 6).
23. Clump analysis (Column 2): candidate clumps can only just supply the remaining stars (row 3, column 1).
24. Clump analysis (Column 4): candidate clumps can only just supply the remaining stars (row 3, column 5).
25. Crowding (Row 6): a star here would leave too little room for its 2 remaining stars (row 7, column 5).
26. Squeeze (rows 2-3): the band's clumps can only just fit its stars (row 4, column 6).
27. Row completion: 2 stars needed, 2 candidates (row 4, column 2).
28. Mark 2 cells adjacent to stars as X (row 3, column 2).
29. Row completion: 1 star needed, 1 candidate (row 4, column 4).
30. Mark 2 cells adjacent to stars as X (row 3, column 4).
31. Region completion: 2 stars needed, 2 candidates (row 5, column 6).
32. Mark 1 cell adjacent to stars as X (row 6, column 6).
33. Region completion: 1 star needed, 1 candidate (row 6, column 2).
34. Mark 1 cell adjacent to stars as X (row 7, column 1).
35. Row completion: 1 star needed, 1 candidate (row 6, column 4).
36. Two last candidates (row 7): Eliminate 1 cell adjacent to both (row 8, column 7).
37. Clump analysis (Row 3): candidate clumps can only just supply the remaining stars (row 2, column 9).
38. Row completion: 2 stars needed, 2 candidates (row 2, column 1).
39. Mark 1 cell adjacent to stars as X (row 1, column 1).
40. Row completion: 1 star needed, 1 candidate (row 2, column 5).
41. Mark 2 cells adjacent to stars as X (row 1, column 5).
42. Column completion: 1 star needed, 1 candidate (row 7, column 6).
43. Mark 2 cells adjacent to stars as X (row 7, column 7).
44. Region completion: 1 star needed, 1 candidate (row 9, column 5).
45. Row completion: 1 star needed, 1 candidate (row 8, column 1).
46. Mark 1 cell adjacent to stars as X (row 9, column 1).
47. Three candidates in a row: Middle cell can't hold a star (row 3, column 8).
48. Region completion: 1 star needed, 1 candidate (row 3, column 7).
49. Row completion: 1 star needed, 1 candidate (row 3, column 9).
50. Region complete: Mark 1 remaining cell as X (row 9, column 7).
51. Column completion: 1 star needed, 1 candidate (row 1, column 7).
52. Mark 1 cell adjacent to stars as X (row 1, column 8).
53. Region complete: Mark 1 remaining cell as X (row 1, column 9).
54. Column completion: 1 star needed, 1 candidate (row 9, column 8).
55. Mark 1 cell adjacent to stars as X (row 9, column 9).
56. Solved! Every row, column, and region has its two stars, none touching.