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