Hard Star Battle answer — January 17, 2026

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 6).
3. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 7).
4. Mark 7 cells adjacent to stars as X (row 4, column 7).
5. Region completion: 1 star needed, 1 candidate (row 3, column 6).
6. Mark 6 cells adjacent to stars as X (row 2, column 5).
7. Region completion: 2 stars needed, 2 candidates (row 6, column 5).
8. Mark 6 cells adjacent to stars as X (row 5, column 4).
9. Region completion: 1 star needed, 1 candidate (row 7, column 7).
10. Mark 4 cells adjacent to stars as X (row 7, column 8).
11. Column 7 complete: Mark 2 remaining cells as X (row 1, column 7).
12. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 3, column 3).
13. 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 2).
14. Three candidates with two adjacent: Isolated candidate must hold a star (row 9, column 1).
15. Mark 2 cells adjacent to stars as X (row 8, column 1).
16. Two-option rule: Cell adjacent to both candidates (row 8, column 4).
17. Two-option rule: Cell adjacent to both candidates (row 9, column 4).
18. Clump analysis (Column 4): candidate clumps can only just supply the remaining stars (row 1, column 3).
19. Two last candidates (column 5): Eliminate 1 cell adjacent to both (row 9, column 6).
20. Column completion: 1 star needed, 1 candidate (row 1, column 6).
21. Clump analysis (Column 3): candidate clumps can only just supply the remaining stars (row 6, column 2).
22. Clump analysis (Column 1): each clump must supply its full share of stars (row 6, column 3).
23. Mark 4 cells adjacent to stars as X (row 5, column 2).
24. Row 6 complete: Mark 2 remaining cells as X (row 6, column 1).
25. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 9).
26. Mark 1 cell adjacent to stars as X (row 8, column 9).
27. Row 7 complete: Mark 1 remaining cell as X (row 7, column 1).
28. Row completion: 2 stars needed, 2 candidates (row 8, column 3).
29. Mark 1 cell adjacent to stars as X (row 9, column 3).
30. Row completion: 1 star needed, 1 candidate (row 8, column 5).
31. Mark 1 cell adjacent to stars as X (row 9, column 5).
32. Clump analysis (Column 2): candidate clumps can only just supply the remaining stars (row 1, column 1).
33. Region completion: 1 star needed, 1 candidate (row 5, column 1).
34. Mark 1 cell adjacent to stars as X (row 4, column 2).
35. Row completion: 2 stars needed, 2 candidates (row 4, column 4).
36. Mark 1 cell adjacent to stars as X (row 3, column 4).
37. Region completion: 2 stars needed, 2 candidates (row 2, column 4).
38. Region completion: 1 star needed, 1 candidate (row 3, column 2).
39. Mark 1 cell adjacent to stars as X (row 2, column 2).
40. Region completion: 1 star needed, 1 candidate (row 1, column 2).
41. Row 1 complete: Mark 2 remaining cells as X (row 1, column 8).
42. Row 3 complete: Mark 2 remaining cells as X (row 3, column 8).
43. Row completion: 1 star needed, 1 candidate (row 4, column 9).
44. Mark 1 cell adjacent to stars as X (row 5, column 9).
45. Column completion: 2 stars needed, 2 candidates (row 2, column 8).
46. Mark 1 cell adjacent to stars as X (row 2, column 9).
47. Column completion: 1 star needed, 1 candidate (row 9, column 8).
48. Mark 1 cell adjacent to stars as X (row 9, column 9).
49. Solved! Every row, column, and region has its two stars, none touching.