Expert Star Battle answer — October 31, 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 6): candidate clumps can only just supply the remaining stars (row 2, column 1).
3. Clump analysis (Region 10): candidate clumps can only just supply the remaining stars (row 2, column 5).
4. Star claim: Region 9 must place a star in row 1; cells touching all its options are eliminated (row 2, column 2).
5. 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 1).
6. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 1).
7. Mark 3 cells adjacent to stars as X (row 4, column 2).
8. Region completion: 1 star needed, 1 candidate (row 3, column 2).
9. Mark 1 cell adjacent to stars as X (row 4, column 3).
10. Crowding (Region 9): a star here would leave too little room for its 2 remaining stars (row 2, column 4).
11. Crowding (Row 2): a star here would leave too little room for its 2 remaining stars (row 1, column 7).
12. Generalized counting (rows 1-1): region star limits exclude these cells (row 1, column 10).
13. Lookahead: Placing star here leads to contradiction - row 1 can only hold 2 stars but the regions there would be forced to place 3 (row 1, column 6).
14. Lookahead: Placing star here leads to contradiction - Row 2 would only have room for 1 of the 2 stars it still needs (row 1, column 5).
15. Lookahead: Placing star here leads to contradiction - row 1 can only hold 2 stars but the regions there would be forced to place 3 (row 4, column 4).
16. Lookahead: Placing star here leads to contradiction - row 1 can only hold 2 stars but the regions there would be forced to place 3 (row 4, column 5).
17. Clump analysis (Row 4): candidate clumps can only just supply the remaining stars (row 5, column 7).
18. Lookahead: Placing star here leads to contradiction - rows 1-3 can only hold 6 stars but the regions there would be forced to place 7 (row 4, column 8).
19. Clump analysis (Row 4): candidate clumps can only just supply the remaining stars (row 3, column 6).
20. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 5, column 4).
21. Lookahead: Placing star here leads to contradiction - rows 1-3 can only hold 6 stars but the regions there would be forced to place 7 (row 4, column 10).
22. Clump analysis (Row 4): each clump must supply its full share of stars (row 4, column 9).
23. Mark 2 cells adjacent to stars as X (row 3, column 8).
24. Two last candidates (row 5): Eliminate 1 cell adjacent to both (row 6, column 4).
25. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 6, column 6).
26. Clump analysis (Region 3): each clump must supply its full share of stars (row 2, column 6).
27. Mark 1 cell adjacent to stars as X (row 3, column 5).
28. Row completion: 1 star needed, 1 candidate (row 3, column 4).
29. Clump analysis (Region 7): candidate clumps can only just supply the remaining stars (row 6, column 8).
30. Three candidates with two adjacent: Isolated candidate must hold a star (row 8, column 10).
31. Mark 5 cells adjacent to stars as X (row 7, column 9).
32. Region completion: 1 star needed, 1 candidate (row 6, column 10).
33. Mark 1 cell adjacent to stars as X (row 6, column 9).
34. Column 10 complete: Mark 2 remaining cells as X (row 2, column 10).
35. Two-option rule: Cell adjacent to both candidates (row 1, column 8).
36. Region completion: 1 star needed, 1 candidate (row 1, column 4).
37. Mark 1 cell adjacent to stars as X (row 1, column 3).
38. Column 4 complete: Mark 4 remaining cells as X (row 7, column 4).
39. Star claim: Region 1 must place a star in row 8; cells touching all its options are eliminated (row 7, column 7).
40. Three candidates with two adjacent: Isolated candidate must hold a star (row 6, column 7).
41. Row 6 complete: Mark 2 remaining cells as X (row 6, column 3).
42. Region completion: 1 star needed, 1 candidate (row 5, column 5).
43. Mark 1 cell adjacent to stars as X (row 4, column 6).
44. Row completion: 1 star needed, 1 candidate (row 4, column 7).
45. Row 5 complete: Mark 1 remaining cell as X (row 5, column 3).
46. Column 7 complete: Mark 2 remaining cells as X (row 8, column 7).
47. Clump analysis (Column 3): candidate clumps can only just supply the remaining stars (row 7, column 2).
48. Row completion: 2 stars needed, 2 candidates (row 7, column 3).
49. Mark 1 cell adjacent to stars as X (row 8, column 3).
50. Row completion: 1 star needed, 1 candidate (row 7, column 5).
51. Mark 2 cells adjacent to stars as X (row 8, column 5).
52. Region completion: 2 stars needed, 2 candidates (row 8, column 8).
53. Mark 1 cell adjacent to stars as X (row 9, column 8).
54. Region completion: 1 star needed, 1 candidate (row 10, column 9).
55. Mark 1 cell adjacent to stars as X (row 10, column 8).
56. Column completion: 1 star needed, 1 candidate (row 1, column 2).
57. Mark 1 cell adjacent to stars as X (row 1, column 1).
58. Column completion: 1 star needed, 1 candidate (row 10, column 1).
59. Row 10 complete: Mark 3 remaining cells as X (row 10, column 3).
60. Region completion: 1 star needed, 1 candidate (row 9, column 3).
61. Column 5 complete: Mark 1 remaining cell as X (row 9, column 5).
62. Region completion: 1 star needed, 1 candidate (row 9, column 6).
63. Column completion: 1 star needed, 1 candidate (row 2, column 8).
64. Mark 1 cell adjacent to stars as X (row 2, column 9).
65. Solved! Every row, column, and region has its two stars, none touching.