Hard Star Battle answer — August 8, 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: This position would block too many candidates (row 7, column 4).
3. Clump analysis (Region 4): candidate clumps can only just supply the remaining stars (row 8, column 6).
4. Clump analysis (Region 6): candidate clumps can only just supply the remaining stars (row 8, column 2).
5. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 5).
6. Mark 5 cells adjacent to stars as X (row 6, column 4).
7. Two-option rule: Cell adjacent to both candidates (row 6, column 2).
8. Two-option rule: Cell adjacent to both candidates (row 7, column 2).
9. Crowding (Row 8): a star here would leave too little room for its 2 remaining stars (row 7, column 8).
10. Undercounting: 2 regions fit in rows 8-9, eliminate 1 outside candidates (row 8, column 9).
11. Clump analysis (Row 8): candidate clumps can only just supply the remaining stars (row 7, column 7).
12. Clump analysis (Row 8): each clump must supply its full share of stars (row 8, column 1).
13. Mark 3 cells adjacent to stars as X (row 7, column 1).
14. Blocking rule: This position would block too many candidates (row 5, column 2).
15. Clump analysis (Column 2): candidate clumps can only just supply the remaining stars (row 1, column 1).
16. Clump analysis (Region 2): candidate clumps can only just supply the remaining stars (row 5, column 7).
17. Clump analysis (Region 3): candidate clumps can only just supply the remaining stars (row 4, column 8).
18. Composite container (columns 3-4): Regions 6 and 9 are confined here, so the leftover cells owe exactly 2 of the band's 4 stars - a star on these cells would crowd them out (row 2, column 5).
19. Composite container (columns 5-9): Regions 1, 2, 3 and 4 are confined here, so the leftover cells owe exactly 1 of the band's 10 stars - a star on these cells would crowd them out (row 2, column 6).
20. Lookahead: Placing star here leads to contradiction - stars at R5C3 and R6C3 would touch (row 5, column 1).
21. Column completion: 1 star needed, 1 candidate (row 6, column 1).
22. Lookahead: Placing star here leads to contradiction - Row 7 would end up with more than 2 stars (row 6, column 7).
23. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 6).
24. Mark 4 cells adjacent to stars as X (row 4, column 5).
25. Crowding (Row 4): a star here would leave too little room for its 2 remaining stars (row 5, column 3).
26. Region completion: 1 star needed, 1 candidate (row 4, column 2).
27. Mark 1 cell adjacent to stars as X (row 3, column 2).
28. Clump analysis (Column 3): candidate clumps can only just supply the remaining stars (row 9, column 4).
29. Region completion: 1 star needed, 1 candidate (row 9, column 3).
30. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 3, column 5).
31. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 8).
32. Mark 3 cells adjacent to stars as X (row 4, column 9).
33. Region completion: 1 star needed, 1 candidate (row 7, column 9).
34. Mark 1 cell adjacent to stars as X (row 8, column 8).
35. Row completion: 1 star needed, 1 candidate (row 4, column 4).
36. Mark 2 cells adjacent to stars as X (row 3, column 4).
37. Region completion: 1 star needed, 1 candidate (row 2, column 4).
38. Mark 1 cell adjacent to stars as X (row 1, column 5).
39. Row completion: 1 star needed, 1 candidate (row 6, column 3).
40. Mark 1 cell adjacent to stars as X (row 7, column 3).
41. Row completion: 1 star needed, 1 candidate (row 8, column 7).
42. Mark 1 cell adjacent to stars as X (row 9, column 6).
43. Column completion: 1 star needed, 1 candidate (row 9, column 5).
44. Region complete: Mark 1 remaining cells as X (row 9, column 9).
45. Two-option rule: Cell adjacent to both candidates (row 3, column 7).
46. Blocking rule: This position would block too many candidates (row 2, column 8).
47. Blocking rule: This position would block too many candidates (row 2, column 9).
48. Two last candidates (column 6): Eliminate 1 cell adjacent to both (row 2, column 7).
49. Region completion: 1 star needed, 1 candidate (row 3, column 6).
50. Row completion: 1 star needed, 1 candidate (row 2, column 2).
51. Mark 1 cell adjacent to stars as X (row 1, column 2).
52. Column 6 complete: Mark 1 remaining cells as X (row 1, column 6).
53. Region completion: 1 star needed, 1 candidate (row 1, column 7).
54. Mark 1 cell adjacent to stars as X (row 1, column 8).
55. Row completion: 1 star needed, 1 candidate (row 1, column 9).
56. Column completion: 1 star needed, 1 candidate (row 3, column 8).
57. Mark 1 cell adjacent to stars as X (row 3, column 9).
58. Solved! Every row, column, and region has its two stars, none touching.