What Is a Whodunit Puzzle? Origin, Mechanics, Modern Examples

A whodunit puzzle is a logic-grid game where every printed clue is a true statement about a small cast of suspects, a set of weapons, a set of rooms, and a set of motives. There are no lies. There are no trick questions. The puzzle is solved when only one assignment of culprit + weapon + room + motive doesn’t contradict any clue. That’s it.

If that sounds dry on paper, it isn’t in practice — because the clues interlock. Knowing that “the doctor sits to the left of the inspector” tells you almost nothing in isolation, but combined with “the inspector did not use the revolver” and “whoever was in the kitchen acted out of jealousy”, you can start ruling out whole rows at once. Five suspects sit at the table when you start; usually three are gone within the first minute. The interesting part is the last twenty seconds, when the remaining two answers feel equally plausible.

Where whodunit puzzles came from

The format borrows from two older traditions:

• The Latin square (Euler, 1782): an n×n grid where each row and each column contains each symbol exactly once. The whodunit grid is structurally the same — each profession appears once across the five suspects, each weapon appears once, and so on.
• Einstein’s “Zebra puzzle” (1962): the canonical word-clue puzzle, often (probably wrongly) attributed to Einstein. It’s the direct ancestor of every modern logic-grid game.

For decades these puzzles lived in newspapers and dedicated puzzle books — Dell, Penny Press, Logic Lover’s. Then in 2022 a developer named Sam Pratt put one online at cluesbysam.com and gave it a daily Wordle-style cadence: same puzzle for everyone, share your time with friends, come back tomorrow. The format went from “puzzle book niche” to “morning ritual” almost overnight.

What makes a whodunit puzzle good

Three things separate puzzles you finish with a satisfied click from puzzles you abandon after two minutes:

1. Honest clues. No clue should be a deliberate distraction. If “the doctor was in the kitchen” is in the case file, the doctor was in the kitchen — full stop. Cheap puzzles bury you in red herrings; good puzzles trust you to follow the math.
2. Exactly one solution. Sounds obvious. Less obvious: most “puzzle generators” don’t actually check this. The result is the dreaded “ambiguous board” where the player solves it correctly and the game still says wrong, because two valid solutions exist and you guessed the other one. At EveryClue we verify every grid with a SAT solver before publishing — multi-solution puzzles never reach the daily rotation.
3. Difficulty by inference depth, not by clue count. An evil-tier puzzle isn’t one with 30 clues. It’s one with 9 clues, of which 6 are conditionals (“if X then Y”). The number of intermediate deductions you have to chain together is what makes it hard.

How to read a clue list

Read it twice before touching the grid. The first pass tells your brain what the categories are. The second pass tells you which clues directly fix a cell. Mark those first. Then look for exclusionary clues — anything that says “X did not use Y” — and cross them out. By the time you’re working on positional clues (“between”, “to the left of”), you should have most of the grid already.

A common beginner mistake is to guess a cell early and then have to undo five guesses later when you realise you contradicted clue #3 four steps back. Take it slow. Murdle and Clues by Sam both lean into honest clue-by-clue reasoning; so do we.

Modern daily whodunits worth bookmarking

• Today’s grid at EveryClue — five suspects, four categories, eight languages, fresh every day.
• Clues by Sam — the daily that started the format’s web revival. English only, single mechanic.
• Murdle — the Wall Street Journal breakout from 2022, now a series of books. Steeper learning curve.
• Mystery-o-matic — open-source generator, two languages, no archive.

If you only do one of these per morning, do the one with the language that’s actually yours — small differences in cultural anchors (the cast list, the rooms, the weapons) compound a lot more than you’d expect over a hundred puzzles.

Try one

The lateral mystery on EveryClue today is a different beast — a yes/no story puzzle with an AI host — but the grid follows the rules above to the letter. New case at 00:00 UTC, free to play, no account required to start.