Hard Star Battle answer — August 30, 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 7, 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 3, column 3).
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 4, column 3).
5. Three candidates with two adjacent: Isolated candidate must hold a star (row 4, column 2).
6. Mark 6 cells adjacent to stars as X (row 3, column 1).
7. Two-option rule: Cell adjacent to both candidates (row 3, column 5).
8. Two-option rule: Cell adjacent to both candidates (row 4, column 5).
9. Clump analysis (Region 1): candidate clumps can only just supply the remaining stars (row 6, column 1).
10. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 8, column 9).
11. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 5, column 6).
12. Clump analysis (Region 9): candidate clumps can only just supply the remaining stars (row 1, column 2).
13. Clump analysis (Region 9): each clump must supply its full share of stars (row 6, column 3).
14. Mark 4 cells adjacent to stars as X (row 5, column 4).
15. Region completion: 2 stars needed, 2 candidates (row 7, column 1).
16. Mark 1 cell adjacent to stars as X (row 8, column 1).
17. Region completion: 1 star needed, 1 candidate (row 8, column 3).
18. Mark 3 cells adjacent to stars as X (row 9, column 2).
19. Column completion: 1 star needed, 1 candidate (row 2, column 2).
20. Mark 4 cells adjacent to stars as X (row 1, column 1).
21. Column completion: 1 star needed, 1 candidate (row 9, column 1).
22. Clump analysis (Column 4): candidate clumps can only just supply the remaining stars (row 1, column 5).
23. Clump analysis (Column 5): candidate clumps can only just supply the remaining stars (row 6, column 6).
24. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 5, column 8).
25. Crowding (Row 5): a star here would leave too little room for its 2 remaining stars (row 4, column 6).
26. Crowding (Region 4): a star here would leave too little room for its 2 remaining stars (row 8, column 7).
27. Clump analysis (Region 8): candidate clumps can only just supply the remaining stars (row 9, column 8).
28. Clump analysis (Region 4): each clump must supply its full share of stars (row 3, column 8).
29. Mark 7 cells adjacent to stars as X (row 2, column 7).
30. Row completion: 1 star needed, 1 candidate (row 4, column 4).
31. Mark 2 cells adjacent to stars as X (row 3, column 4).
32. Region completion: 2 stars needed, 2 candidates (row 3, column 6).
33. Mark 1 cell adjacent to stars as X (row 2, column 6).
34. Region completion: 1 star needed, 1 candidate (row 6, column 5).
35. Mark 2 cells adjacent to stars as X (row 7, column 5).
36. Row completion: 1 star needed, 1 candidate (row 2, column 4).
37. Mark 1 cell adjacent to stars as X (row 1, column 4).
38. Row completion: 2 stars needed, 2 candidates (row 5, column 7).
39. Mark 1 cell adjacent to stars as X (row 6, column 7).
40. Region completion: 1 star needed, 1 candidate (row 8, column 5).
41. Mark 2 cells adjacent to stars as X (row 9, column 5).
42. Region completion: 1 star needed, 1 candidate (row 9, column 7).
43. Mark 1 cell adjacent to stars as X (row 8, column 8).
44. Row completion: 1 star needed, 1 candidate (row 5, column 9).
45. Mark 1 cell adjacent to stars as X (row 6, column 9).
46. Column completion: 1 star needed, 1 candidate (row 1, column 6).
47. Mark 1 cell adjacent to stars as X (row 1, column 7).
48. Region complete: Mark 1 remaining cell as X (row 1, column 8).
49. Row completion: 1 star needed, 1 candidate (row 1, column 9).
50. Region complete: Mark 1 remaining cell as X (row 7, column 9).
51. Column 7 complete: Mark 1 remaining cell as X (row 7, column 7).
52. Region completion: 1 star needed, 1 candidate (row 7, column 8).
53. Solved! Every row, column, and region has its two stars, none touching.