Medium Queens Puzzles
Needs the group-lock techniques, where several regions together reserve the same rows or columns. Most boards land here.
8,632 boards land in this tier. The rating is measured, not estimated: every board is solved by the hint engine and tagged with the hardest technique it genuinely required.
9 queens left to place.
Tap once to rule a cell out, twice to place a queen. Right-click marks an exclusion directly. Arrow keys move between cells.
A 9x9 board split into 9 colour regions, needing 9 queens: one per row, one per column, one per region, none touching. Regions run from 1 to 30 cells.
Where these boards are
- 6×6 28 medium
- 7×7 417 medium
- 8×8 697 medium
- 9×9 946 medium
- 10×10 1,344 medium
- 11×11 1,361 medium
- 12×12 1,253 medium
- 13×13 1,179 medium
- 14×14 779 medium
- 15×15 628 medium
How this board is solved
Solving this 9x9 board takes 16 deductions and needs the intermediate group-lock techniques, drawing on 4 distinct techniques. The first queen you can place for certain is I1. The queens resolve in the order I1 → D8 → H7 → G9 → F5 → E2 → A4 → C3 → B6. Every step follows by logic, so you never have to guess.
Techniques this board needs
Full solution, step by step (16 deductions)
- Single-cell region essential
Single-cell region. This colour covers only one cell, so its queen goes there. Place a queen at I1.
- Region line lock essential
Region line lock. This colour must use row 3, so nothing else can. This reasons over row 3. Rules out A3, D3, E3, F3, G3, H3.
- Region line lock essential
Region line lock. This colour must use column 8, so nothing else can. This reasons over column 8. Rules out H4, H5, H6, H9.
- Shared diagonal neighbour intermediate
Shared diagonal neighbour. Every remaining option for this colour touches these cells, so they are out. Rules out B2, C2, B4, C4.
- Shared diagonal neighbour intermediate
Shared diagonal neighbour. Every remaining option for this colour touches these cells, so they are out. Rules out G7, G8.
- Region line lock essential
Region line lock. This colour must use row 9, so nothing else can. This reasons over row 9. Rules out A9, B9, C9, D9.
- Forced queen essential
Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at D8.
- Forced queen essential
Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at H7.
- Region line lock essential
Region line lock. This colour must use column 6, so nothing else can. This reasons over column 6. Rules out F2, F4, F9.
- Forced queen essential
Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at G9.
- Region line lock essential
Region line lock. This colour must use row 6, so nothing else can. This reasons over row 6. Rules out E6, F6.
- Forced queen essential
Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at F5.
- Forced queen essential
Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at E2.
- Forced queen essential
Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at A4.
- Forced queen essential
Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at C3.
- Forced queen essential
Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at B6.
Answer: queens at I1, D8, H7, G9, F5, E2, A4, C3, B6.