Murder sudoku glossary
Every word you meet on the board, in the clue list and in the guides, explained in a sentence or two. Each entry links to the page that covers it in full.
The case
Case
One puzzle: a floor plan, a list of people and their clues. It ends when you name the killer.
How to play →Daily case
The case of the day, the same for every player and in the app. A new one comes out at midnight UTC.
Today's case →Suspect
A person on the case. Every suspect stands on exactly one cell, and one of them is the killer.
Rules →Victim
The person who was killed. The victim is placed like everyone else and was alone in a room with the killer.
Rules →Killer
The one other person in the victim's room. You never pick the killer by instinct: the finished board names them.
Rules →Clue
A short, true fact on a person's card, such as "She was beside a plant." No clue is a lie and none is there for show.
Clue types →Case cold
What you see when the board is wrong. Reopen the case and check your crosses.
How to play →Archive
Every past daily case, still playable, each with a worked solution once its day is over.
Archive and solutions →The board
Board
A square grid drawn as a floor plan, from 4×4 up to 9×9. A case has as many people as the board has rows.
Rules →Cell
One square of the board. A person stands on one cell, and cells are named by row and column.
Rules →Room
A named area of the board, closed off by thick walls. A room can hold any number of people, except the victim's room.
Rules →Object
Furniture or scenery drawn on a cell, such as a chair, a bed, a plant or a table. Clues often point to one.
Rules →Seat
An object a person can sit, lie or stand on: chair, armchair, sofa, bed, bench, stool, carpet or rug.
Rules →Blocked cell
A cell with solid scenery, such as a plant, a table, a statue or a bookshelf. Nobody can stand there.
Rules →Words in the clues
In a room
"She was in the Library" means somewhere inside that room. Some rooms read "on", like on the Terrace.
Clue types →Beside
Directly above, below, left or right, and only within the same room. Diagonals never count, and neither does a cell across a wall.
Clue types →Corner
A cell whose room walls meet on two sides, such as the top and the left. Inner corners of an L-shaped room count too.
Clue types →With another man
Exactly one other man was in that room. Women may be there as well. "With another woman" works the same way.
Clue types →Top row, left column
Rows count from the top and columns from the left: "the second row" is the one under the top row.
Rules →Solving
Deduction
A step you can prove from the rules and the clues. Every case can be solved with deductions alone, with no guessing.
Techniques →Ruled out
A cell you know a person cannot be on. On the board you mark it with a cross.
Read every clue as a map →Cross
The mark for a ruled-out cell. Crossing out early and often is most of the work.
Read every clue as a map →Notes
Pencil marks for the cells a person might still be on, so you can keep possibilities without committing to them.
How to play →Placed
A person whose cell is certain. Placing someone closes their row and column for everyone else.
How to play →Open cell
A cell that is still possible for a person: not crossed out, not blocked, and not in a row or column someone else holds.
Read every clue as a map →One solution
Every published case has exactly one arrangement that fits all the clues, and a solver checks it before the case goes out.
Rules →Techniques
Reading clues
Turn each clue into the set of cells it allows and cross out the rest before you place anyone.
Read every clue as a map →Pinned suspect
A person whose open cells all sit in one row or column. That line is theirs, so cross it out for everyone else.
Pinned suspects →Only one fits
A row or column that only one person can still reach. That person is in it, wherever else they could have gone.
The only one who fits →Room counting
Using the clues that count people in a room: the victim and exactly one other, "alone", and "with another man".
Room counting →Shared rows
Two people who between them can only reach the same two rows fill both, so nobody else can use those rows. Columns work the same way.
Shared rows and columns →Contradiction
Assume a cell, follow the easy techniques, and cross the cell out if a rule breaks. Expert cases need it.
Follow it to a contradiction →Levels and the app
Easy
Cases solved by reading clues, pinned suspects and "only one fits". The daily case is Easy on Monday and Tuesday.
Difficulty and hints →Medium
Easy moves plus room counting, at least twice. The daily case is Medium on Wednesday and Thursday.
Difficulty and hints →Hard
Room counting plus shared rows or columns. The daily case is Hard on Friday and Sunday.
Difficulty and hints →Expert
Everything above, plus at least two steps that need a contradiction. The daily case is Expert on Saturday.
Difficulty and hints →Board size
Shown next to the level, such as 6×6. Size and difficulty are separate: a big Easy case can be gentler than a small Hard one.
Difficulty and hints →Hint
Help when you are stuck. On the web a hint places the selected person; in the app it first points you to the next deduction.
Difficulty and hints →Detective rank
A title in the app that grows with the cases you solve, from Rookie through Constable, Sergeant, Inspector and Chief Inspector to Superintendent.
The app →Event night
A themed case on a set date, such as the eight Halloween Nights from October 26 to November 2.
Halloween Nights →Put it to work on a real case
A new murder at midnight UTC, free in the browser, with one arrangement that fits every clue.