How to Solve Queens-Style Puzzles: 7 Techniques
Queens-style puzzles (LinkedIn Queens, Star Battle, and our own CrownGrid) look simple, but a good board can stump you for minutes if you don't have a system. The key thing to remember: these puzzles never require guessing. Every move can be deduced. Here are seven techniques, roughly from easiest to most advanced.
The rules, in one line
Place exactly one crown in every row, every column and every colored region, and never let two crowns touch — not even diagonally.
1. Start with the smallest regions
A region that covers only one or two cells is your best friend. A one-cell region forces a crown immediately; a two-cell region narrows things down fast. Always scan for the most constrained region first.
2. Mark, don't guess
Every time you place a crown, immediately mark an ✕ on its entire row, its entire column, its whole region, and all eight neighboring cells. Those squares are now dead. In CrownGrid this happens automatically, but the habit of "eliminate everything a crown forbids" is the heart of the solve.
3. Look for the last open cell
After marking, constantly re-scan rows, columns and regions for a line that has just one cell left without an ✕. That cell must be a crown. Placing it usually triggers a fresh wave of eliminations.
4. The region squeeze
If every cell of a region lies within a single row (or column), then that row's crown must belong to that region — even if you don't yet know which cell. You can therefore ✕ out the rest of that row in all other regions. This is the single most powerful intermediate technique.
5. Adjacency chains
Because two crowns can't touch, placing one crown removes up to eight surrounding cells. In tight corners this often cascades: one placement forces an ✕, which leaves a single open cell in a column, which forces another crown, and so on.
6. Counting columns against regions
With N regions spread across N rows and N columns, each line holds exactly one crown. If a block of columns is "owned" by a set of regions that exactly fills them, no other region can place a crown there. Comparing how many lines a group of regions can occupy versus how many it must occupy rules out whole areas.
7. The two-cell pivot
When a region is down to two candidate cells, check what both options have in common. If both candidates share a row, that region's crown is in that row no matter what — so you can ✕ the rest of the row immediately, often before you've resolved the region itself.
Practice makes it automatic
These techniques become second nature with repetition — which is exactly why an unlimited board helps. Try them out on CrownGrid: start at 6×6 to drill the basics, then move up to 8×8 once the region squeeze feels natural.