About Eight Queens
Place eight queens on a chessboard so none share a row, column or diagonal. Keep the fixed queens in their sockets and work around closed squares, which prevent placement without blocking attacks.
Explore 12 studies with different final arrangements. Begin with four fixed queens, then work toward sparse one-queen starts. Undo a choice, try another route and keep your first solve time for each board.
How to play
- Goal
- Place eight non-attacking queens while keeping the fixed queens and avoiding closed squares.
- How it ends
- The board is complete when all eight queens obey those rules; there is no loss.
- Record
- Your first solve time is kept per board, alongside the fastest verified first solve and its holder.
- Choose a board to reveal its clues and start its first clock. Place eight queens in total, counting the fixed queens.
- Tap an open square to place a queen. Tap one of your own queens to remove it. Queens in bronze socket rings are fixed and cannot be moved. On a small screen, use the arrow controls and Place / remove instead.
- No two queens may share a row, column or diagonal, however far apart they are. Red marks and lines show attacking pairs.
- Closed stone squares cannot hold queens. They do not block a queen’s attack line.
- A placement with no current conflict can still lead to a dead end. Remove a queen or use Undo to explore another route.
- Undo and Redo restore your own placements. Restart clears your queens while keeping the first clock running. Later replays are Practice and preserve your first finish.
Controls
| Input | Action |
|---|---|
| Tap an open square | Place or remove your queen |
| Arrow controls → Place / remove | Select and act on a square in the compact layout |
| Arrow keys, then Enter or Space | Select a square and place or remove a queen |
| Delete | Remove your queen from the selected square |
| Z or Backspace / Y | Undo / Redo |
| R / Escape | Request Restart / close a panel or go back |
| Gamepad D-pad / A | Select and activate |
| Gamepad LB / RB | Undo / Redo |
| Gamepad B / Start | Go back / open settings |
Tips
- Scan one row When every open square but one is attacked, that row has a forced placement. Check columns and both diagonals before placing it.
- Follow the whole line Distance and closed squares do not interrupt a diagonal attack. Look all the way to the edge.
- Keep a retreat A safe-looking queen can leave another row with no choice. Undo the recent placements and test a different route.
Good to know
Your progress stays in this browser when storage is available. Menus, Restart and chooser visits keep the first clock running. Reloaded unfinished attempts keep their progress but their times stay local. Practice preserves your first finish. Sound, music and reduced motion can be changed in Settings. No account is needed.
Watch how to play
Questions
Do closed squares block attacks?
No. They forbid placement only. Queens attack across them.
Can I move a fixed queen?
No. A bronze socket ring marks a queen that must stay. Your own queens can be removed and replaced.
Does each board have one answer?
Yes. Each study has one arrangement under its fixed-queen and closed-square clues.
Why are there 12 studies?
The campaign covers the 12 fundamentally different classic eight-queen endings, counting rotations and reflections as the same ending. Each study uses a different one.
Is this a colored-region Queens puzzle?
No. These are classic chess-queen attacks across entire rows, columns and diagonals. There are no colored-region or adjacent-only attack rules.
Can Practice improve my first time?
No. Your first completed time is kept; later completions are Practice.
