About the game
Murder mystery logic puzzles
A murder mystery logic puzzle is a whodunit you solve with deduction instead of guesswork. Every clue is true, every case has exactly one answer, and the killer is whoever the logic leaves standing.
How The Black Files works
Each case is a floor plan drawn on a 7×7 grid: a hotel lobby, a restaurant kitchen, a parking garage. Seven people were there when the body was found. Your job is to place all seven on the map using a short list of evidence, such as "Grace was sitting on the sofa" or "Fabian was the westernmost person at the scene."
Three rules hold everything together. There is one person in every row and every column. People can only be on floor squares or seats; dark squares are furniture and objects. And the map is split into four zones: the killer was alone with the victim, so the victim's zone holds exactly two people. Place everyone correctly and the killer reveals themselves.
Why it is a logic puzzle, not a guessing game
Classic mystery games often reward the best hunch. Here, a solver checks every case before it is published to make sure the evidence allows only one arrangement. That changes how you play: when you are stuck, it is never bad luck. There is always a clue, or a combination of a clue with the row and column rule, that tells you something new. If you enjoy logic grid puzzles, Sudoku or nonograms, the feeling is familiar, with a story on top.
From cadet to master detective
Cases come in eight ranks. CADET cases fall into place clue by clue and take a few minutes. Middle ranks bring in negative clues, compass clues and the crime-zone rule, so facts have to be combined before anything is certain. At MASTER DETECTIVE there is no safe first move: you have to assume something, follow it and see whether it breaks.
A new case every day
A new Black File opens every day on Sleuthic. It is free, needs no account and works on a phone. Your time, hints and streak are saved on your device, you can share your result without spoilers, and yesterday's case gets a full step-by-step solution. The community compares deductions on r/BlackFiles.