Daily Puzzle

How Stones Works

Stones is a placement puzzle in the same family as the classic queens puzzles: a square grid divided into colored regions, and three rules that interlock harder than they look.

1. Place exactly one stone in every row, every column and every region.
2. No two stones may touch — not even diagonally.
3. Every puzzle has exactly one solution, reachable by pure logic. No guessing required, ever.

Tap a cell once to mark it as empty, twice to place a stone. Conflicts light up immediately, the timer starts on your first move, and your streak lives in your browser — no account needed.

One Puzzle a Day, for Everyone

A new Stones puzzle appears every day at midnight UTC, and everyone in the world plays the same grid. Weekday puzzles run smaller and friendlier; weekend grids are larger and meaner. If you finish early, Practice mode serves random puzzles from the vault without touching your streak.

Solving Tips from the Setter

• Start with the smallest region. A region of one or two cells often forces its stone immediately — and every placed stone eliminates a whole row, column and neighborhood.
• Mark before you place. Strong solvers spend most of their taps on elimination marks. The stones place themselves once enough cells are crossed off.
• Watch for trapped rows. If all of a region’s remaining cells sit in one row, no other region can use that row — eliminate accordingly.
• Two-cell pincers. Two diagonal-adjacent candidate cells kill the cell between them: a stone in either one rules it out.

If you enjoy constraint puzzles, the same logical muscles get a longer workout in sudoku and the rest of the browser games — or measure your raw pattern memory in the Mind Lab.