About Eight Queens
The eight queens puzzle asks you to place eight chess queens on a board so that no two share a row, a column or a diagonal. It was first published by the chess composer Max Bezzel in 1848, and Carl Friedrich Gauss was working on it within a couple of years. A full chessboard has 92 solutions, but finding one by hand still takes thought. This page starts on smaller boards, where four queens on a 4 × 4 board have only two answers, and finishes with puzzles where some queens are already placed and only a few arrangements, or just one, still work.
How to play Eight Queens
- A queen attacks along its row, its column and both diagonals. Tap a safe square to place a queen, and tap a queen to take it off.
- Squares under attack are striped, so you can only place a queen where it is safe. Queens that were given at the start stay put.
- If an empty row or column has no safe square left, the board can’t be finished: undo or start again.
- Every placing and taking off counts, even ones you undo, so the stars go to a clean solve. Your progress is saved on this device only.
Tips & strategy
- Every row and every column needs exactly one queen, so think one row at a time.
- Queens a knight’s move apart never attack each other, and many solutions are built from steps like that.
- When a row has no safe square left, go back to the last queen you placed and move it along, rather than starting again.
- On a 6 × 6 board only four arrangements work, and none of them uses a corner square.
Eight Queens: questions and answers
How many solutions are there?
On a full 8 × 8 chessboard, 92, or 12 if mirror images and turns of the board count as the same. A 4 × 4 board has 2, a 5 × 5 board 10, a 6 × 6 board 4 and a 7 × 7 board 40.
Why can I only place a queen on a safe square?
The shading shows every square under attack, and the game only lets a queen go where no other queen reaches. The puzzle is then about the order: choosing squares that leave room for the rest.
Is my progress saved?
Yes, in your browser on this device: the boards you have solved, your stars and your best result for each.