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