Hard Star Battle answer — January 2, 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. 3-cell region rule: Middle cell can't hold a star (row 5, column 1).
3. Region completion: 2 stars needed, 2 candidates (row 4, column 1).
4. Mark 4 cells adjacent to stars as X (row 3, column 1).
5. Region completion: 1 star needed, 1 candidate (row 6, column 1).
6. Mark 3 cells adjacent to stars as X (row 6, column 2).
7. Column 1 complete: Mark 4 remaining cells as X (row 1, column 1).
8. Three candidates with two adjacent: Isolated candidate must hold a star (row 4, column 3).
9. Mark 5 cells adjacent to stars as X (row 3, column 3).
10. Region completion: 1 star needed, 1 candidate (row 2, column 2).
11. Mark 3 cells adjacent to stars as X (row 1, column 2).
12. Row 4 complete: Mark 5 remaining cells as X (row 4, column 5).
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 8, column 8).
14. 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 9).
15. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 9).
16. Mark 3 cells adjacent to stars as X (row 6, column 8).
17. Two last candidates (column 2): Eliminate 2 cells adjacent to both (row 8, column 3).
18. Two last candidates (column 3): Eliminate 2 cells adjacent to both (row 6, column 4).
19. Clump analysis (Row 3): candidate clumps can only just supply the remaining stars (row 2, column 6).
20. Clump analysis (Row 5): candidate clumps can only just supply the remaining stars (row 6, column 6).
21. Clump analysis (Column 4): candidate clumps can only just supply the remaining stars (row 1, column 5).
22. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 7, column 6).
23. Star claim: Region 8 must place a star in row 5; cells touching all its options are eliminated (row 5, column 8).
24. Crowding (Row 8): a star here would leave too little room for its 2 remaining stars (row 7, column 3).
25. Column completion: 1 star needed, 1 candidate (row 6, column 3).
26. Row 6 complete: Mark 2 remaining cells as X (row 6, column 5).
27. Three candidates with two adjacent: Isolated candidate must hold a star (row 9, column 4).
28. Mark 1 cell adjacent to stars as X (row 8, column 4).
29. Region completion: 1 star needed, 1 candidate (row 7, column 5).
30. Mark 1 cell adjacent to stars as X (row 8, column 6).
31. Row 7 complete: Mark 1 remaining cell as X (row 7, column 7).
32. Row completion: 2 stars needed, 2 candidates (row 8, column 2).
33. Mark 1 cell adjacent to stars as X (row 9, column 2).
34. Row completion: 1 star needed, 1 candidate (row 8, column 7).
35. Mark 3 cells adjacent to stars as X (row 9, column 6).
36. Region completion: 1 star needed, 1 candidate (row 9, column 9).
37. Column completion: 2 stars needed, 2 candidates (row 1, column 8).
38. Mark 4 cells adjacent to stars as X (row 1, column 7).
39. Row completion: 1 star needed, 1 candidate (row 2, column 4).
40. Mark 2 cells adjacent to stars as X (row 1, column 4).
41. Region completion: 1 star needed, 1 candidate (row 3, column 6).
42. Mark 1 cell adjacent to stars as X (row 3, column 7).
43. Region completion: 1 star needed, 1 candidate (row 1, column 6).
44. Column completion: 1 star needed, 1 candidate (row 5, column 5).
45. Mark 1 cell adjacent to stars as X (row 5, column 6).
46. Column completion: 1 star needed, 1 candidate (row 5, column 7).
47. Row 5 complete: Mark 1 remaining cell as X (row 5, column 9).
48. Column completion: 1 star needed, 1 candidate (row 3, column 8).
49. Mark 1 cell adjacent to stars as X (row 3, column 9).
50. Solved! Every row, column, and region has its two stars, none touching.