Expert Star Battle answer — December 13, 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 7, column 4).
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 5, column 4).
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 8, column 6).
5. Clump analysis (Region 2): candidate clumps can only just supply the remaining stars (row 2, column 9).
6. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 5, column 2).
7. Clump analysis (Region 4): candidate clumps can only just supply the remaining stars (row 6, column 6).
8. Star claim: Region 7 must place a star in column 7; cells touching all its options are eliminated (row 8, column 7).
9. Composite container (rows 1-2): Region 9 is confined here, so the leftover cells owe exactly 2 of the band's 4 stars - a star on these cells would crowd them out (row 1, column 6).
10. Generalized counting (columns 6-9): region star limits exclude these cells (row 3, column 5).
11. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 7).
12. Mark 3 cells adjacent to stars as X (row 6, column 7).
13. Joint analysis (Region 6 + Row 6): every legal combination of their stars rules these cells out (row 7, column 2).
14. Joint analysis (Column 4 + Column 3): every legal combination of their stars rules these cells out (row 6, column 2).
15. Composite container (rows 1-5): Regions 1, 2, 3 and 9 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 4, column 6).
16. Clump analysis (Region 1): candidate clumps can only just supply the remaining stars (row 2, column 8).
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 4, column 8).
18. 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 9).
19. Clump analysis (Region 2): candidate clumps can only just supply the remaining stars (row 6, column 9).
20. Generalized counting (rows 3-3): region star limits exclude these cells (row 3, column 6).
21. Squeeze (rows 3-4): the band's clumps can only just fit its stars (row 3, column 8).
22. Region completion: 2 stars needed, 2 candidates (row 3, column 9).
23. Region completion: 1 star needed, 1 candidate (row 5, column 9).
24. Region completion: 1 star needed, 1 candidate (row 9, column 6).
25. Column completion: 1 star needed, 1 candidate (row 2, column 6).
26. Mark 2 cells adjacent to stars as X (row 1, column 5).
27. Column completion: 1 star needed, 1 candidate (row 4, column 7).
28. Column completion: 2 stars needed, 2 candidates (row 1, column 8).
29. Mark 1 cell adjacent to stars as X (row 1, column 9).
30. Column completion: 1 star needed, 1 candidate (row 9, column 8).
31. Mark 2 cells adjacent to stars as X (row 8, column 9).
32. Region complete: Mark 1 remaining cell as X (row 7, column 9).
33. Row 9 complete: Mark 4 remaining cells as X (row 9, column 1).
34. Three candidates in a column: Middle cell can't hold a star (row 6, column 5).
35. Row completion: 2 stars needed, 2 candidates (row 6, column 1).
36. Mark 2 cells adjacent to stars as X (row 5, column 1).
37. Row completion: 1 star needed, 1 candidate (row 6, column 3).
38. Mark 2 cells adjacent to stars as X (row 5, column 3).
39. Row completion: 1 star needed, 1 candidate (row 5, column 5).
40. Mark 1 cell adjacent to stars as X (row 4, column 4).
41. Region complete: Mark 1 remaining cell as X (row 4, column 3).
42. Row completion: 1 star needed, 1 candidate (row 7, column 5).
43. Mark 1 cell adjacent to stars as X (row 8, column 4).
44. Region completion: 1 star needed, 1 candidate (row 8, column 3).
45. Mark 1 cell adjacent to stars as X (row 8, column 2).
46. Region completion: 1 star needed, 1 candidate (row 8, column 1).
47. Column 1 complete: Mark 4 remaining cells as X (row 1, column 1).
48. Row completion: 1 star needed, 1 candidate (row 4, column 2).
49. Mark 2 cells adjacent to stars as X (row 3, column 2).
50. Region completion: 1 star needed, 1 candidate (row 3, column 4).
51. Mark 2 cells adjacent to stars as X (row 2, column 3).
52. Row completion: 1 star needed, 1 candidate (row 2, column 2).
53. Mark 2 cells adjacent to stars as X (row 1, column 2).
54. Region completion: 1 star needed, 1 candidate (row 1, column 4).
55. Solved! Every row, column, and region has its two stars, none touching.