Expert Star Battle answer — July 28, 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 9, column 9).
3. Blocking rule: This position would block too many candidates (row 4, column 3).
4. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 5, column 4).
5. Star claim: Region 8 must place a star in row 3; cells touching all its options are eliminated (row 2, column 3).
6. Crowding (Region 8): a star here would leave too little room for its 2 remaining stars (row 4, column 2).
7. Undercounting: 3 regions fit in cols 8-10, eliminate 9 outside candidates (row 2, column 8).
8. Clump analysis (Column 8): candidate clumps can only just supply the remaining stars (row 9, column 7).
9. Clump analysis (Column 8): each clump must supply its full share of stars (row 1, column 8).
10. Mark 4 cells adjacent to stars as X (row 1, column 7).
11. Clump analysis (Column 9): candidate clumps can only just supply the remaining stars (row 3, column 10).
12. Clump analysis (Region 4): candidate clumps can only just supply the remaining stars (row 3, column 6).
13. Generalized counting (rows 1-5): region star limits exclude these cells (row 5, column 5).
14. Blocking rule: This position would block too many candidates (row 7, column 4).
15. Clump analysis (Region 5): candidate clumps can only just supply the remaining stars (row 7, column 6).
16. Composite container (rows 6-10): Regions 1, 3, 5 and 7 are confined here, so the leftover cells owe exactly 2 of the band's 10 stars - a star on these cells would crowd them out (row 7, column 2).
17. Lookahead: Placing star here leads to contradiction - column 1 can only hold 2 stars but the regions there would be forced to place 3 (row 9, column 3).
18. Lookahead: Placing star here leads to contradiction - columns 5-7 must hold 6 stars but the regions there could only supply 5 (row 9, column 4).
19. Joint analysis (Region 8 + Region 9): every legal combination of their stars rules these cells out (row 6, column 2).
20. Triple analysis (Region 8 + Region 5 + Region 4): every legal combination of their stars rules these cells out (row 6, column 6).
21. Lookahead: Placing star here leads to contradiction - columns 5-7 must hold 6 stars but the regions there could only supply 5 (row 8, column 4).
22. Joint analysis (Region 8 + Column 4): every legal combination of their stars rules these cells out (row 2, column 5).
23. Blocking rule: This position would block too many candidates (row 4, column 6).
24. Generalized counting (rows 3-5): region star limits exclude these cells (row 5, column 10).
25. Three candidates with two adjacent: Isolated candidate must hold a star (row 2, column 10).
26. Mark 1 cell adjacent to stars as X (row 3, column 9).
27. Region completion: 1 star needed, 1 candidate (row 4, column 9).
28. Triple analysis (Region 8 + Row 2 + Region 4): every legal combination of their stars rules these cells out (row 5, column 2).
29. Three candidates with two adjacent: Isolated candidate must hold a star (row 8, column 5).
30. Mark 4 cells adjacent to stars as X (row 7, column 5).
31. Region completion: 1 star needed, 1 candidate (row 6, column 5).
32. Mark 1 cell adjacent to stars as X (row 5, column 6).
33. Column 5 complete: Mark 4 remaining cells as X (row 1, column 5).
34. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 7).
35. Mark 2 cells adjacent to stars as X (row 4, column 7).
36. Region completion: 1 star needed, 1 candidate (row 3, column 7).
37. Mark 1 cell adjacent to stars as X (row 2, column 6).
38. Row completion: 1 star needed, 1 candidate (row 4, column 1).
39. Mark 3 cells adjacent to stars as X (row 3, column 1).
40. Row completion: 1 star needed, 1 candidate (row 5, column 3).
41. Column completion: 2 stars needed, 2 candidates (row 1, column 6).
42. Row 1 complete: Mark 4 remaining cells as X (row 1, column 1).
43. Column completion: 1 star needed, 1 candidate (row 10, column 6).
44. Column 7 complete: Mark 2 remaining cells as X (row 7, column 7).
45. Two-option rule: Cell adjacent to both candidates (row 8, column 2).
46. Two-option rule: Cell adjacent to both candidates (row 2, column 4).
47. Column completion: 2 stars needed, 2 candidates (row 3, column 4).
48. Mark 1 cell adjacent to stars as X (row 3, column 3).
49. Column completion: 1 star needed, 1 candidate (row 10, column 4).
50. Mark 1 cell adjacent to stars as X (row 10, column 3).
51. Row 10 complete: Mark 4 remaining cells as X (row 10, column 1).
52. Column completion: 2 stars needed, 2 candidates (row 2, column 2).
53. Mark 1 cell adjacent to stars as X (row 2, column 1).
54. Column completion: 1 star needed, 1 candidate (row 9, column 2).
55. Mark 3 cells adjacent to stars as X (row 8, column 1).
56. Region completion: 1 star needed, 1 candidate (row 7, column 3).
57. Row completion: 1 star needed, 1 candidate (row 8, column 10).
58. Mark 2 cells adjacent to stars as X (row 7, column 9).
59. Region completion: 1 star needed, 1 candidate (row 6, column 9).
60. Region completion: 1 star needed, 1 candidate (row 9, column 8).
61. Row 6 complete: Mark 1 remaining cells as X (row 6, column 1).
62. Region completion: 1 star needed, 1 candidate (row 7, column 1).
63. Solved! Every row, column, and region has its two stars, none touching.