Solve a new murder mystery every day using logic, clues and deduction. Deduce is a free, Murdle-style detective puzzle: every morning a case opens with a victim, a set of suspects, a set of rooms and a set of weapons. Read the clues, work the deduction grid, and file one accusation — who did it, where, and with what.
It is free with nothing to install, runs in any browser, and takes most detectives ten to twenty minutes. Cases get progressively harder across five detective ranks, and every one is verified by a solver before it is published.
Deduce is a free daily logic-grid detective puzzle. Each case gives you a victim, a set of suspects, a set of rooms and a set of weapons, plus a list of clues. Exactly one combination fits every clue, and your job is to find it and file a single accusation: who did it, where, and with what.
Yes. Every daily case and the whole archive of past cases are free, with no paywall, no advertising and nothing to buy. There is no app to install — it runs in a browser on a phone, tablet or computer.
Yes. You can play the daily case anonymously and your solve still appears on the leaderboard under an anonymous handle. An account is free and keeps your solve streak, your progress between devices, and unlocks the higher detective ranks.
They belong to the same family of puzzle: a murder mystery solved on a logic deduction grid, with a new one every day, free in the browser. If you enjoy Murdle you will recognise how a Deduce case works immediately.
Three differences. Deduce cases are generated and machine-verified by a constraint solver rather than hand-written, so every published case is proven to be solvable by deduction alone. Difficulty is a progressive ladder of five detective ranks you unlock by solving, rather than a weekly cycle. And the top rank adds a fourth axis — the time each suspect arrived — on a five-by-five board.
Read the clues, then use the grid to rule out what cannot be true. Negative clues ("not in the library") are usually the most useful, because each one removes a possibility permanently. When a row has one square left uncrossed, that square is true. When the board is complete, file your accusation. A wrongful arrest ends your streak, so it pays to finish the grid rather than guess.
Yes. A new case opens at midnight UTC and closes at the next, and it is the same case for every detective that day — so times on the leaderboard are directly comparable.
Yes. Every case that has closed stays permanently playable in the case archive, which currently holds several hundred cases. Solutions are never published there.
Yes. Free printable packs are available as PDFs — ten complete cases each, with a deduction grid printed beside every case and all the solutions in an appendix at the back. They are laid out for A4 and print cleanly on US Letter too, in black and white so they photocopy well. No email address or account is needed to download one, and the cases in a pack are generated for it, so they never appear as daily cases or in the archive.
Five, in order: Rookie Detective, Junior Investigator, Inspector, Master Detective and Grand Sleuth. Junior is where you start and Rookie is a lighter practice tier; Inspector unlocks at 10 solves, Master Detective at 20 and Grand Sleuth at 40. Each rank adds new kinds of clue rather than simply adding more of them.
At deduce.studio, in any modern browser. There is no app store download and no installation.
More questions and answers · Deduce as a free Murdle alternative · How Deduce puzzles are generated and verified
Play today's case · Browse the daily puzzle archive · How to solve a logic-grid puzzle