Murdoku for Sudoku Players

If you play Sudoku, you already know more Murdoku than you think. Both are logic puzzles with exactly one solution, both are solved by elimination rather than guessing, and both reward the same habit of asking what cannot be true rather than what might be. A good deal of what you have learned transfers directly. Some of it does not, and a few things in Murdoku have no Sudoku equivalent at all.

What Carries Over

The line rule is the same idea. In Sudoku every row and column holds each digit once; in Murdoku every row and column holds exactly one person. So the line techniques work exactly as you know them: a naked single is the last tile for a suspect, a hidden single is the only suspect who can still reach a row, and naked pairs and triples become locked lines — two suspects confined to the same two rows fill them, and nobody else may use them.

Pencil marks carry over too. A tap in Murdoku leaves a note without placing anyone, and the habit of noting candidates for the most constrained piece first is just as useful here.

What Does Not

There are no boxes. A Murdoku board is cut into rooms, and rooms look like Sudoku regions, but there is no rule that each room holds one person. A room can hold three people or none. So box-based techniques — pointing pairs, box-line reduction — have no direct counterpart; the room reasoning that replaces them is driven by clues, not by a rule.

There are also no givens. A Sudoku starts with digits on the board; a Murdoku starts with an empty floor plan and a list of witness statements. Nothing is placed until you place it, which is why the opening of a hard Murdoku case can feel emptier than any Sudoku.

What Is New

Clues. Instead of digits, every suspect comes with statements: on a chair, beside a window, north of Dana, in a room with no other woman. Each one defines an area rather than a cell, and the puzzle is in combining areas. Clues that relate two suspects to each other are the closest thing Murdoku has to a hard Sudoku technique: they say nothing on their own and a great deal once one of the two is pinned down.

The murder. The victim also takes a row and a column, and the victim is always alone with exactly one suspect — the murderer. That second rule is a constraint like any other and finishes about a quarter of all cases. Sudoku has nothing like it, and it is easy to forget until a case refuses to close.

Where to Start

Boards run from four by four to twelve by twelve, but most cases sit between six by six and nine by nine. Begin with a few easy cases on small boards to learn how clues read, then move to medium. The line techniques you already know will carry you a long way; the new skills are reading clues as areas and remembering the murder rule.

Good First Cases

Easy cases on the smallest boards — a quick way to learn how the clues read:

More Strategy

The Techniques

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