How to play CrownGrid

CrownGrid is a logic puzzle of pure deduction — no guessing required. Here are the rules and the strategies that solve every board.

The rules

• The board is divided into colored regions. On an 8×8 board there are 8 regions.
• Place exactly one crown in each region.
• Place exactly one crown in each row and one in each column.
• No two crowns may touch — not horizontally, vertically, or diagonally.

Controls

• Tap once → ✕ (mark a cell that cannot hold a crown).
• Tap again → ♛ (place a crown).
• Tap a third time → clear the cell.
• Use ✕ marks liberally — they're your scratch pad for elimination.

Beginner strategy

1. Start with small regions. A region that occupies only one or two cells forces its crown's location quickly.
2. Eliminate, don't guess. When you place a crown, mark ✕ on its whole row, whole column, its region, and all eight neighbors.
3. Look for "only one open cell." If a row, column, or region has just one cell left without an ✕, that's a crown.

Advanced techniques

1. Region squeeze: if every cell of a region sits inside a single row (or column), then that whole row/column's crown belongs to this region — mark ✕ on the rest of the row in other regions.
2. Adjacency chains: two crowns can't be neighbors, so placing one prunes up to eight surrounding cells, which often cascades into forced moves elsewhere.
3. Counting: with N regions across N rows and N columns, each line holds exactly one crown — use that to rule out over-crowded areas.

Common mistakes

• Guessing instead of eliminating. Every board is solvable by logic — if you're stuck, mark ✕ more aggressively rather than placing a crown on a hunch.
• Forgetting the diagonal. Crowns can't touch even diagonally, so placing one rules out all eight surrounding cells, not just the four orthogonal neighbours.
• Ignoring small regions. A region squeezed into one or two cells is usually the fastest forced move on the board — start there.

Frequently asked questions

Try it now