What is Crowns?
Crowns is a daily logic puzzle based on the n-queens problem. Each board is divided into coloured regions and requires exactly one crown in every row, every column and every region. No two crowns may share a row, column or diagonal, and no two may touch at any corner. The boards grow through the week, starting small on Monday and reaching their largest size on Sunday. Every puzzle has exactly one solution, everyone receives the same board, and it resets at midnight UTC.
How to play Crowns
Tap a cell to cycle through three states: empty, crossed out, and crown.
Place one crown in every row, column, and coloured region.
Crowns cannot share a row, column, or diagonal, and they cannot touch at the corners.
Use the controls below the board. Undo removes your last move, Hint gives you a clue, and Clear Board removes all marks so you can start again.
The crown counter beside the clock shows how many crowns you have placed and how many the board requires.
The board provides immediate red feedback. Any crown that breaks a rule turns red the moment you place it, so violations are visible instantly rather than waiting for submission. A timer starts from your first action and runs at the top of the screen. The crown counter tracks your progress toward the target number. Because illegal crowns cost nothing except the visual warning, the cross mark becomes the primary thinking tool and the crown represents a commitment.
Use crosses to narrow the board
Every crown eliminates a row, a column, a region and all eight neighboring cells. Mark these dead squares with crosses instead of holding constraints in memory, and the board will simplify itself step by step. Start with the smallest coloured region because it occupies fewer rows and columns, which forces crowns out of those lines elsewhere and often produces the first genuine deduction. The uniqueness guarantee is a logical tool: if you encounter an ambiguity you cannot resolve, you have misread a constraint rather than reached a point where guessing is required.
Modes and access
The Daily board offers one puzzle per day, identical for all players and rotating at UTC midnight. An Archive link below the board provides access to past puzzles. The game requires no signup and loads directly into play.
Tips for a smoother solve
Board size increases from Monday to Sunday, so the difficulty and time commitment vary by day. Treat the three-state tap as your main control: marking ruled-out squares quickly is as important as placing crowns. Because each puzzle guarantees a unique solution, an apparent dead end means you missed a constraint, not that you should guess. If you find yourself stuck, revisit the smallest regions and check whether earlier crowns have opened new deductions elsewhere.