D
EWhat It Is
Murder mystery sudoku is a logic puzzle. There is a map divided into areas — a living room, a kitchen, a garden… — with their furniture, and a list of suspects. Each one signs a card with a sentence about where they were: “I was in the Kitchen”, “I was next to the plant”, “I was north of Bruno”.
With those sentences and one rule borrowed from sudoku, each person ends up with only one possible square. Once everyone is placed, the case closes itself.
It is also called murder sudoku or mystery sudoku. It became popular with the Murdoku books, and anyone who has played those will recognize the rules straight away.
No Numbers, and Not Killer Sudoku
The name is misleading in two ways.
There are no numbers. Only one rule comes from sudoku: one person per row and one per column. No digits from 1 to 9, no three-by-three boxes. If you have never done a sudoku, that's fine.
It is not killer sudoku. That's a different game: a regular sudoku with cages whose digits must add up to a given total. Murder mystery sudoku has no sums. It has a murder.
The Rules in Four Sentences
One person per row and one per column, the victim included. Squares fully taken up by a piece of furniture are shaded and out of play.
The cards tell the truth. If a case has a liar, you are told before you start.
“Next to” means on the neighboring square and in the same area. Walls block it, even when two squares touch.
The murderer is whoever is alone with the victim. Once the map is full, there is only one other person in the victim's area.
Alice“I was in the Living Room.”
Bruno“I was next to the plant.”
BAKitchenBedroomLiving RoomHow to Solve a Case
Read every card before you place anyone. Start with the one that leaves the fewest squares: “I was on the rug” places someone right away if there is only one rug on the map.
Every person you place crosses out their row and their column for everyone else. That's the sudoku rule, and it is what closes the map little by little.
Cards that mention someone else wait. “I was next to Bruno” says nothing until Bruno has a place; after that, it almost always places someone.
The victim goes last. When all the suspects are in place, the victim takes the last free square, and that area tells you who did it.
The full method, with every technique illustrated, is in how to solve a case, and the rules with a case solved step by step are in how to play.
AB
CVKitchenBedroomLiving RoomThe Liar and the Accomplice
Two twists change the way you think about the case.
With a liar, one of the cards is false. You don't know which: you find it because it clashes with the others, which can't all be true at once. From then on, what it says is not true, and that person could be anywhere.
With an accomplice, one of the suspects was keeping watch from an area adjacent to the crime scene, and a clue mentions them. The murderer is still whoever is alone with the victim; the accomplice is a second culprit you also have to find.
In both cases, the game tells you at the top before you start.
How Long It Takes
A five-by-five map with four suspects takes a few minutes and is the best way to learn. The medium ones, eight or nine squares across, are perfect for a quiet evening. The big ones, with a liar or an accomplice, will fill a whole afternoon.
What It's Called in Other Languages
- Spanish sudoku de asesinato
- French sudoku meurtre
- Italian sudoku con delitto
- German Mordsudoku
- Portuguese sudoku de assassinato
- Dutch moordsudoku
It's the same game everywhere, and on Sudoku Detective you can play the cases in seven languages.
Where to Play
On paper, in the book: Sudoku Detective, in paperback and in full color, with the solution to every case explained step by step.
In your browser, free: new cases every week, on your phone or computer, with no account and nothing to install. The Hint button works out the next step when you get stuck.
To print: cases as PDFs, in color and in black and white, with the solution on a separate sheet.
Against an opponent: the duel, one case for two detectives.
Frequently Asked Questions
What is murder mystery sudoku?
A logic puzzle: you place suspects on a map, one per row and one per column, based on what each one says. There is exactly one solution, and the murderer is whoever ends up alone with the victim.
Do I need to know how to play sudoku?
No. Only one rule comes from sudoku: one person per row and one per column. There are no numbers.
Is it the same as killer sudoku?
No. Killer sudoku is a number sudoku with sums. Murder mystery sudoku has no numbers: you place people on a map.
Is it the same as Murdoku?
It's the same kind of game. Murdoku is the series of books that made it popular; Sudoku Detective is a different one, with its own cases, free online and in a book.
How do you find the murderer?
Once everyone is placed, look at the victim's area: the only other person there is the murderer.
Where can I play for free?
On sudokudetective.com, in your browser or by printing the cases as PDFs, with no sign-up.
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