Medium Star Battle answer — August 28, 2025

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 9, column 2).
3. Three candidates with two adjacent: Isolated candidate must hold a star (row 9, column 1).
4. Mark 2 cells adjacent to stars as X (row 8, column 1).
5. Two-option rule: Cell adjacent to both candidates (row 8, column 4).
6. Two-option rule: Cell adjacent to both candidates (row 9, column 4).
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 7, column 5).
8. Three candidates with two adjacent: Isolated candidate must hold a star (row 7, column 4).
9. Mark 6 cells adjacent to stars as X (row 6, column 3).
10. Region completion: 1 star needed, 1 candidate (row 9, column 3).
11. Row 9 complete: Mark 5 remaining cells as X (row 9, column 5).
12. Two-option rule: Cell adjacent to both candidates (row 7, column 7).
13. Two-option rule: Cell adjacent to both candidates (row 8, column 7).
14. Three candidates with two adjacent: Isolated candidate must hold a star (row 8, column 8).
15. Mark 3 cells adjacent to stars as X (row 7, column 8).
16. Row completion: 1 star needed, 1 candidate (row 8, column 6).
17. Mark 1 cell adjacent to stars as X (row 7, column 6).
18. Two-option rule: Cell adjacent to both candidates (row 5, column 6).
19. Two-option rule: Cell adjacent to both candidates (row 5, column 7).
20. Blocking rule: a star here would touch every other open cell in its region, leaving no room for the region's second star (row 5, column 9).
21. Three candidates with two adjacent: Isolated candidate must hold a star (row 4, column 9).
22. Mark 4 cells adjacent to stars as X (row 3, column 8).
23. Two last candidates (row 7): Eliminate 2 cells adjacent to both (row 6, column 1).
24. Three candidates with two adjacent: Isolated candidate must hold a star (row 5, column 4).
25. Mark 5 cells adjacent to stars as X (row 4, column 3).
26. Column 4 complete: Mark 3 remaining cells as X (row 1, column 4).
27. Three candidates in a column: Middle cell can't hold a star (row 2, column 5).
28. Column completion: 2 stars needed, 2 candidates (row 1, column 5).
29. Mark 2 cells adjacent to stars as X (row 1, column 6).
30. Region completion: 1 star needed, 1 candidate (row 1, column 7).
31. Mark 3 cells adjacent to stars as X (row 1, column 8).
32. Row 1 complete: Mark 4 remaining cells as X (row 1, column 1).
33. Column completion: 1 star needed, 1 candidate (row 3, column 5).
34. Mark 2 cells adjacent to stars as X (row 3, column 6).
35. Column completion: 1 star needed, 1 candidate (row 6, column 6).
36. Mark 1 cell adjacent to stars as X (row 6, column 7).
37. Column completion: 1 star needed, 1 candidate (row 6, column 8).
38. Mark 1 cell adjacent to stars as X (row 6, column 9).
39. Column completion: 1 star needed, 1 candidate (row 2, column 9).
40. 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).
41. 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 2).
42. Three candidates with two adjacent: Isolated candidate must hold a star (row 2, column 1).
43. Mark 1 cell adjacent to stars as X (row 3, column 1).
44. Row 2 complete: Mark 1 remaining cell as X (row 2, column 3).
45. Region completion: 1 star needed, 1 candidate (row 3, column 3).
46. Mark 1 cell adjacent to stars as X (row 4, column 2).
47. Row 3 complete: Mark 1 remaining cell as X (row 3, column 7).
48. Region completion: 1 star needed, 1 candidate (row 4, column 7).
49. Row 4 complete: Mark 1 remaining cell as X (row 4, column 1).
50. Column 1 complete: Mark 2 remaining cells as X (row 5, column 1).
51. Region completion: 1 star needed, 1 candidate (row 5, column 2).
52. Region completion: 1 star needed, 1 candidate (row 7, column 2).
53. Solved! Every row, column, and region has its two stars, none touching.