Expert Star Battle answer — December 29, 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 8, column 1).
3. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 1).
4. Mark 4 cells adjacent to stars as X (row 6, column 1).
5. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 5, column 4).
6. Clump analysis (Region 8): candidate clumps can only just supply the remaining stars (row 2, column 8).
7. Lookahead: Placing star here leads to contradiction - row 5 can only hold 2 stars but the regions there would be forced to place 3 (row 5, column 3).
8. Composite container (rows 1-4): Regions 1 and 2 are confined here, so the leftover cells owe exactly 4 of the band's 8 stars - a star on these cells would crowd them out (row 3, column 5).
9. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 3, column 4).
10. Joint analysis (Row 5 + Row 6): every legal combination of their stars rules these cells out (row 7, column 4).
11. Joint analysis (Row 7 + Region 4): every legal combination of their stars rules these cells out (row 7, column 5).
12. Triple analysis (Region 5 + Region 3 + Column 5): every legal combination of their stars rules these cells out (row 9, column 6).
13. Triple analysis (Region 5 + Region 3 + Column 6): every legal combination of their stars rules these cells out (row 4, column 5).
14. Clump analysis (Region 5): each clump must supply its full share of stars (row 4, column 4).
15. Squeeze (columns 2-3): the band's clumps can only just fit its stars (row 4, column 1).
16. Joint analysis (Row 3 + Row 2): every legal combination of their stars rules these cells out (row 1, column 4).
17. Triple analysis (Row 3 + Row 2 + Region 2): every legal combination of their stars rules these cells out (row 1, column 3).
18. Joint analysis (Column 3 + Column 2): every legal combination of their stars rules these cells out (row 6, column 4).
19. Squeeze (columns 4-5): each clump in the band must supply its full share of stars (row 6, column 5).
20. Mark 3 cells adjacent to stars as X (row 5, column 6).
21. Clump analysis (Region 3): candidate clumps can only just supply the remaining stars (row 7, column 8).
22. Crowding (Row 5): a star here would leave too little room for its 2 remaining stars (row 4, column 8).
23. Squeeze (columns 5-6): the band's clumps can only just fit its stars (row 3, column 7).
24. Composite container (rows 7-9): Regions 4 and 9 are confined here, so the leftover cells owe exactly 3 of the band's 6 stars - a star on these cells would crowd them out (row 8, column 8).
25. Composite container (rows 1-6): Regions 1, 2, 5, 7 and 8 are confined here, so the leftover cells owe exactly 1 of the band's 12 stars - a star on these cells would crowd them out (row 5, column 8).
26. Clump analysis (Region 8): candidate clumps can only just supply the remaining stars (row 1, column 8).
27. Column completion: 2 stars needed, 2 candidates (row 3, column 8).
28. Mark 4 cells adjacent to stars as X (row 2, column 7).
29. Region completion: 1 star needed, 1 candidate (row 1, column 9).
30. Column completion: 1 star needed, 1 candidate (row 9, column 8).
31. Mark 4 cells adjacent to stars as X (row 8, column 7).
32. Clump analysis (Row 8): candidate clumps can only just supply the remaining stars (row 7, column 3).
33. Squeeze (rows 4-5): the band's clumps can only just fit its stars (row 6, column 9).
34. Region completion: 1 star needed, 1 candidate (row 5, column 9).
35. Row completion: 1 star needed, 1 candidate (row 7, column 7).
36. Mark 2 cells adjacent to stars as X (row 6, column 7).
37. Region completion: 1 star needed, 1 candidate (row 8, column 5).
38. Mark 1 cell adjacent to stars as X (row 8, column 4).
39. Region completion: 1 star needed, 1 candidate (row 8, column 3).
40. Mark 1 cell adjacent to stars as X (row 9, column 2).
41. Region completion: 1 star needed, 1 candidate (row 9, column 1).
42. Row completion: 1 star needed, 1 candidate (row 6, column 3).
43. Mark 1 cell adjacent to stars as X (row 5, column 2).
44. Column 1 complete: Mark 4 remaining cells as X (row 1, column 1).
45. Region completion: 1 star needed, 1 candidate (row 4, column 2).
46. Mark 1 cell adjacent to stars as X (row 3, column 2).
47. Row completion: 1 star needed, 1 candidate (row 3, column 6).
48. Mark 3 cells adjacent to stars as X (row 2, column 5).
49. Region completion: 1 star needed, 1 candidate (row 5, column 7).
50. Column 3 complete: Mark 1 remaining cell as X (row 2, column 3).
51. Row completion: 2 stars needed, 2 candidates (row 2, column 2).
52. Mark 1 cell adjacent to stars as X (row 1, column 2).
53. Row completion: 1 star needed, 1 candidate (row 2, column 4).
54. Mark 1 cell adjacent to stars as X (row 1, column 5).
55. Column completion: 1 star needed, 1 candidate (row 1, column 6).
56. Mark 1 cell adjacent to stars as X (row 1, column 7).
57. Solved! Every row, column, and region has its two stars, none touching.