Queens Grid

Hard Queens Puzzles

Requires testing a queen and following the consequences of a placement before committing to it. Still pure logic, never a guess.

4,805 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 2 to 25 cells.

Where these boards are

How this board is solved

Solving this 9x9 board takes 18 deductions and needs expert techniques, including testing a queen, drawing on 6 distinct techniques. It opens on column 1, ruling cells out before any queen goes down. The queens resolve in the order A3 → E1 → C7 → B5 → D4 → H6 → F9 → I8 → G2. Every step follows by logic, so you never have to guess.

Techniques this board needs

Full solution, step by step (18 deductions)
  1. Region line lock essential

    Region line lock. This colour must use column 1, so nothing else can. This reasons over column 1. Rules out A4, A5, A6, A7, A8, A9.

  2. Region line lock essential

    Region line lock. This colour must use row 1, so nothing else can. This reasons over row 1. Rules out A1, B1, C1, F1, G1, H1, I1.

  3. Region line lock essential

    Region line lock. This colour must use row 2, so nothing else can. This reasons over row 2. Rules out A2, B2, C2, D2, H2.

  4. Forced queen essential

    Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at A3.

  5. Region line lock essential

    Region line lock. This colour must use column 4, so nothing else can. This reasons over column 4. Rules out D1, D6, D7, D8, D9.

  6. Forced queen essential

    Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at E1.

  7. Shared diagonal neighbour intermediate

    Shared diagonal neighbour. Every remaining option for this colour touches these cells, so they are out. Rules out C4, C5.

  8. Shared diagonal neighbour intermediate

    Shared diagonal neighbour. Every remaining option for this colour touches these cells, so they are out. Rules out F8.

  9. Shared diagonal neighbour intermediate

    Shared diagonal neighbour. Every remaining option for this colour touches these cells, so they are out. Rules out H8.

  10. Two-region group lock intermediate

    Two-region group lock. 2 colours fit in only 2 rows, reserving them. This reasons over row 8 and row 9. Rules out B8, C8, B9, C9.

  11. Forced queen essential

    Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at C7.

  12. Forced queen essential

    Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at B5.

  13. Forced queen essential

    Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at D4.

  14. Ruled out either way expert

    Ruled out either way. These cells are ruled out no matter where this colour's queen goes. Rules out H9.

  15. Last cell in a line essential

    Last cell in a line. Column 8 has one legal cell left, so its queen goes there. Place a queen at H6. This reasons over column 8.

  16. Last cell in a line essential

    Last cell in a line. Column 6 has one legal cell left, so its queen goes there. Place a queen at F9. This reasons over column 6.

  17. Forced queen essential

    Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at I8.

  18. Forced queen essential

    Forced queen. This colour has one legal cell left, so its queen goes there. Place a queen at G2.

Answer: queens at A3, E1, C7, B5, D4, H6, F9, I8, G2.

Other difficulties