A good Sudoku has exactly one solution and a path a person can follow to it. Draw your idea (digits, thermometers, arrows, cages, dots), and the setter’s assistant checks it after every change: how many solutions, where it’s still ambiguous, how far logic gets, and how hard it is.
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A book of your own puzzles, in chapters. It opens on a blank grid, with the setter’s assistant beside it.
Play the featured books and see what other players have made
Browse the Books →A book is a journey through worlds: each has a name and a look (its colours, moving scene and music), a few puzzles and a 👑 boss that opens the next world. Tap a puzzle to set it. Every puzzle shows what the assistant thinks of it: ✓ one solution, ⚠ more than one, ✗ none.