Expert Star Battle answer — December 21, 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 6, column 5).
3. Three candidates with two adjacent: Isolated candidate must hold a star (row 6, column 4).
4. Mark 7 cells adjacent to stars as X (row 5, column 3).
5. Two-option rule: Cell adjacent to both candidates (row 5, column 7).
6. Two-option rule: Cell adjacent to both candidates (row 6, 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 1, column 2).
8. Three candidates with two adjacent: Isolated candidate must hold a star (row 1, column 3).
9. Mark 4 cells adjacent to stars as X (row 1, column 4).
10. Clump analysis (Region 2): candidate clumps can only just supply the remaining stars (row 4, column 1).
11. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 8, column 6).
12. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 8, column 8).
13. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 8, column 2).
14. Squeeze (rows 7-8): the band's clumps can only just fit its stars (row 9, column 4).
15. Squeeze (columns 2-3): the band's clumps can only just fit its stars (row 6, column 1).
16. Squeeze (columns 4-5): the band's clumps can only just fit its stars (row 2, column 6).
17. Generalized counting (rows 1-4): region star limits exclude these cells (row 5, column 8).
18. Composite container (columns 5-9): Regions 1, 3, 4 and 7 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 6, column 6).
19. Region completion: 1 star needed, 1 candidate (row 5, column 6).
20. Mark 3 cells adjacent to stars as X (row 4, column 5).
21. Crowding (Row 4): a star here would leave too little room for its 2 remaining stars (row 3, column 3).
22. Squeeze (rows 2-3): the band's clumps can only just fit its stars (row 3, column 6).
23. Two last candidates (column 6): Eliminate 1 cell adjacent to both (row 8, column 5).
24. Clump analysis (Column 5): each clump must supply its full share of stars (row 9, column 5).
25. Mark 2 cells adjacent to stars as X (row 8, column 4).
26. Column completion: 1 star needed, 1 candidate (row 4, column 4).
27. Mark 2 cells adjacent to stars as X (row 3, column 5).
28. Column completion: 1 star needed, 1 candidate (row 2, column 5).
29. Column completion: 1 star needed, 1 candidate (row 7, column 6).
30. Mark 1 cell adjacent to stars as X (row 7, column 7).
31. Two last candidates (column 3): Eliminate 1 cell adjacent to both (row 9, column 2).
32. Crowding (Row 3): a star here would leave too little room for its 2 remaining stars (row 4, column 8).
33. Crowding (Row 8): a star here would leave too little room for its 2 remaining stars (row 7, column 2).
34. Region completion: 1 star needed, 1 candidate (row 9, column 8).
35. Mark 3 cells adjacent to stars as X (row 8, column 9).
36. Region completion: 1 star needed, 1 candidate (row 8, column 3).
37. Mark 1 cell adjacent to stars as X (row 9, column 3).
38. Row completion: 1 star needed, 1 candidate (row 8, column 1).
39. Mark 2 cells adjacent to stars as X (row 7, column 1).
40. Three candidates in a column: Middle cell can't hold a star (row 2, column 7).
41. Region completion: 1 star needed, 1 candidate (row 3, column 7).
42. Column completion: 1 star needed, 1 candidate (row 1, column 7).
43. Mark 1 cell adjacent to stars as X (row 1, column 8).
44. Row 1 complete: Mark 2 remaining cells as X (row 1, column 1).
45. Region completion: 1 star needed, 1 candidate (row 2, column 1).
46. Mark 2 cells adjacent to stars as X (row 3, column 1).
47. Region completion: 1 star needed, 1 candidate (row 4, column 2).
48. Mark 2 cells adjacent to stars as X (row 5, column 1).
49. Region completion: 1 star needed, 1 candidate (row 6, column 2).
50. Row 2 complete: Mark 1 remaining cell as X (row 2, column 9).
51. Row completion: 1 star needed, 1 candidate (row 3, column 9).
52. Mark 1 cell adjacent to stars as X (row 4, column 9).
53. Row completion: 1 star needed, 1 candidate (row 5, column 9).
54. Mark 2 cells adjacent to stars as X (row 6, column 8).
55. Column completion: 1 star needed, 1 candidate (row 7, column 8).
56. Mark 1 cell adjacent to stars as X (row 7, column 9).
57. Solved! Every row, column, and region has its two stars, none touching.