Queens #20 (October 15, 2026): solution and step-by-step

Each step is a deduction a person can make, in the order our solver found them. Rows and columns are counted from the top-left corner.

1. Cross out row 2, column 8. This cell touches every free cell of the mint region — a queen here would leave the mint region with no queen, so it's crossed out.

2. Cross out row 7, column 6. This cell touches every free cell of the rose region — a queen here would leave the rose region with no queen, so it's crossed out.

3. Cross out 7 cells. The mint region and the lime region all fit inside columns 8 and 9, so those 2 columns' queens are theirs — every other cell in columns 8 and 9 is crossed out.

4. Cross out 7 cells. The coral region and the rose region all fit inside columns 6 and 7, so those 2 columns' queens are theirs — every other cell in columns 6 and 7 is crossed out.

5. Cross out 7 cells. Every free cell of the lavender region is in column 5, so that region's queen must be there — the rest of column 5 is crossed out.

6. Queen at row 8, column 4. The teal region has only one free cell left — that must be its queen.

7. Cross out 5 cells. Queens can't touch, not even diagonally — the cells around this queen are crossed out.

8. Cross out 6 cells. Row 8 already has its queen — the rest of it is crossed out.

9. Cross out 6 cells. Column 4 already has its queen — the rest of it is crossed out.

10. Queen at row 7, column 7. The rose region has only one free cell left — that must be its queen.

11. Cross out 4 cells. Queens can't touch, not even diagonally — the cells around this queen are crossed out.

12. Cross out 3 cells. Row 7 already has its queen — the rest of it is crossed out.

18 more steps follow the same pattern until the 9 queens are placed.

Queens by row: row 1: column 1 (gold); row 2: column 5 (lavender); row 3: column 8 (mint); row 4: column 2 (sky); row 5: column 6 (coral); row 6: column 3 (orchid); row 7: column 7 (rose); row 8: column 4 (teal); row 9: column 9 (lime).