How to play Sudoku Murder
Sudoku Murder is a murder mystery logic puzzle drawn as a floor plan. You read short clues about each suspect, work out where everyone was standing, and the placement tells you who the killer is. This page has the rules, a first case solved move by move, the mistakes new detectives make and answers to the usual questions.
What kind of puzzle it is
Each case is a whodunit on a grid. Someone was killed in a manor, a garden or a theatre, a handful of suspects were there, and every suspect has one or two plain facts on their card. You place every person on the floor plan so that all the facts hold, and the finished plan shows who was alone with the victim.
The puzzle takes one rule from sudoku: no two people share a row or a column. There are no numbers to add up, and you need no sudoku practice. Boards run from 4×4 to 9×9. The free daily case changes at midnight UTC and climbs from Easy on Monday to Expert on Saturday, so early in the week is a good time to start.
The case, step by step
Read the board
The board is a square grid split into rooms by thick walls. Each room has a name and its own floor. Some cells hold objects: things a person can sit, lie or stand on, like a chair or a bed, and solid scenery, like a plant or a table, that nobody can stand on.
Meet the suspects
A case has as many people as the grid has rows. One of them is the victim. Each person carries one or two clues, written as plain facts: "He was in the Library." "She was not beside a table."
One per row and column
Place every person on a cell so that no two share a row or a column. That is the sudoku half of the puzzle, and it does a lot of the work.
Use the clues to rule cells out
Cross out every cell a clue forbids. When a person has only one row left, nobody else can use that row. Keep going until everyone has exactly one cell.
Name the killer
The victim was alone in a room with exactly one other person. That person is the killer. Submit your solution to close the case.
Every kind of clue, with examples and the usual mistakes: clue types.
A first case, move by move
The practice case further down is a 4×4 manor with four people. Oscar is the victim, and Jonas, Paula and Dario are the suspects. Play it first if you would rather work it out yourself. This is how it solves.
Paula takes the chair
Paula was on a chair, and the board has one chair: in the Pantry, top row, third column. Paula goes there, and the top row and the third column are closed to everyone else.
Dario takes the stool
Dario was on a stool. The only stool is in the Great Hall, second row, second column. Dario goes there, and the second row and second column close as well.
Jonas finds the Kitchen bed
Jonas was in the Kitchen, the strip of three cells down the right-hand side. Its top two cells sit in rows that Paula and Dario already hold, so Jonas takes the third: the bed in the third row.
Oscar fills the last gap
Only Oscar is left, with one free row and one free column: the bottom row and the left column. They cross on the bed in the Great Hall, where Oscar was lying.
Name the killer
The Great Hall holds Oscar and one other person, Dario. Paula is in the Pantry and Jonas in the Kitchen. Dario was alone with the victim, so Dario is the killer.
Bigger cases work the same way, with more clues and fewer free placements. When the object and room clues run out, the six techniques on the tips page take over.
Try a practice case
A 4×4 case with four people. Everything on this page is all you need.
The victim. He was alone with the killer.
Pick a suspect, then tap a cell.
Play this case and the whole casebook in the app, free on iPhone, iPad and Android.
The tools
Mistakes new detectives make
Counting diagonals as beside
Beside means directly above, below, left or right. A plant on a diagonal does not count, and neither does one across a wall in the next room.
Standing on scenery
Plants, tables, statues, clocks and other solid objects block their cell. Chairs, beds, stools, sofas, benches and rugs can be sat, lain or stood on.
Forgetting the victim
The victim takes a row and a column like everyone else. Leave them out and the rows stop adding up.
Reading "with another man" loosely
It means exactly one other man in that room. Women may be there too.
Placing on a hunch
Cross out cells for every suspect before you place anyone. A placement made early on a hunch is hard to undo once other moves depend on it.
Picking the most suspicious person
The clues describe positions and nothing else. The killer is whoever ends up in the victim's room, however innocent their card sounds.