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