Medium Star Battle answer — May 23, 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. 3-cell region rule: Middle cell can't hold a star (row 1, column 2).
3. Region completion: 2 stars needed, 2 candidates (row 1, column 1).
4. Mark 2 cells adjacent to stars as X (row 2, column 1).
5. Region completion: 1 star needed, 1 candidate (row 1, column 3).
6. Mark 3 cells adjacent to stars as X (row 1, column 4).
7. Row 1 complete: Mark 5 remaining cells as X (row 1, column 5).
8. 3-cell region rule: Middle cell can't hold a star (row 6, column 8).
9. Region completion: 2 stars needed, 2 candidates (row 5, column 8).
10. Mark 7 cells adjacent to stars as X (row 4, column 7).
11. Region completion: 1 star needed, 1 candidate (row 7, column 8).
12. Mark 5 cells adjacent to stars as X (row 7, column 7).
13. Column 8 complete: Mark 3 remaining cells as X (row 2, column 8).
14. 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 3).
15. Three candidates with two adjacent: Isolated candidate must hold a star (row 4, column 4).
16. Mark 7 cells adjacent to stars as X (row 3, column 3).
17. Region completion: 2 stars needed, 2 candidates (row 2, column 5).
18. Mark 2 cells adjacent to stars as X (row 2, column 6).
19. Region completion: 1 star needed, 1 candidate (row 2, column 7).
20. Mark 1 cell adjacent to stars as X (row 3, column 7).
21. Row 2 complete: Mark 1 remaining cell as X (row 2, column 9).
22. Region completion: 2 stars needed, 2 candidates (row 3, column 9).
23. Region completion: 1 star needed, 1 candidate (row 9, column 9).
24. Column completion: 1 star needed, 1 candidate (row 9, column 7).
25. Mark 2 cells adjacent to stars as X (row 8, column 6).
26. Row 9 complete: Mark 5 remaining cells as X (row 9, column 1).
27. Two-option rule: Cell adjacent to both candidates (row 3, column 1).
28. Row completion: 1 star needed, 1 candidate (row 3, column 2).
29. Mark 2 cells adjacent to stars as X (row 4, column 1).
30. Row completion: 1 star needed, 1 candidate (row 4, column 6).
31. Mark 1 cell adjacent to stars as X (row 5, column 6).
32. Two last candidates (row 5): Eliminate 2 cells adjacent to both (row 6, column 1).
33. Two last candidates (column 6): Eliminate 2 cells adjacent to both (row 6, column 5).
34. Column completion: 1 star needed, 1 candidate (row 8, column 5).
35. Mark 3 cells adjacent to stars as X (row 7, column 4).
36. Region completion: 1 star needed, 1 candidate (row 6, column 6).
37. Column completion: 1 star needed, 1 candidate (row 6, column 4).
38. Mark 2 cells adjacent to stars as X (row 6, column 3).
39. Column completion: 1 star needed, 1 candidate (row 8, column 3).
40. Mark 2 cells adjacent to stars as X (row 7, column 2).
41. Region completion: 1 star needed, 1 candidate (row 7, column 1).
42. Mark 1 cell adjacent to stars as X (row 8, column 1).
43. Column 1 complete: Mark 1 remaining cell as X (row 5, column 1).
44. Region completion: 1 star needed, 1 candidate (row 5, column 2).
45. Solved! Every row, column, and region has its two stars, none touching.