Queens Puzzles

15,333 boards, 6×6 through 15×15. Every one has been checked by an exhaustive solver: exactly one solution, reachable by deduction alone.

By size

By difficulty

Easy 1,896 boards: Solvable with the basic deductions alone: forced queens and single-line region locks. The place to learn the game.
Medium 8,632 boards: Needs the group-lock techniques, where several regions together reserve the same rows or columns. Most boards land here.
Hard 4,805 boards: Requires testing a queen and following the consequences of a placement before committing to it. Still pure logic, never a guess.

How difficulty is decided

Each board is solved by the same engine that powers the hint button, which records every deduction it needs. The rating is the hardest technique that turned out to be necessary, so it reflects the reasoning a board actually demands rather than just how big the grid is — a 15×15 can be gentler than a tight 9×9.

The techniques page explains each one, and every puzzle page shows which ones its board needs.