Hi Product Hunt! I'm the developer of Casebook on SnackTurn. Casebook is a collection of everyday deduction mysteries. Read the public rules and reliable evidence, mark possibilities in your notebook, then choose the person who fits every clue. There are 36 cases across Starter, Intermediate and Expert. All three levels are available from the start. Each case has three optional hints and an explanation after you solve it. There is no timer, and progress stays in your browser. For a first case, try The Borrowed Umbrella: four people, four umbrellas and three records. You only need to identify the person holding the red umbrella; you don't need to fill every notebook cell. It's free to play in English or Simplified Chinese, with no account or download. I'd like to hear which deductions felt satisfying and where the notebook or wording was unclear. AI tools helped with development and this launch copy.

Casebook

Everyday mysteries. Follow the clues. Find the answer.

Everyday mysteries. Follow the clues. Find the answer.