Room for Murder Daily › Blog › How to Solve a Murder Sudoku — 12 Techniques from Easy to Expert
How to Solve a Murder Sudoku — 12 Techniques from Easy to Expert
Murder sudoku puzzles look hard until you know where to start. These twelve solving techniques take you from your first 5×5 case to Saturday's 7×7 and the lying-killer Sunday.
- Start with the most restrictive statement — the suspect who fits the fewest squares.
- After every placement, cross out that row and column at once.
- Use room capacity: a room two rows tall can never hold more than two people.
- The victim is usually placed last, in the only square left; the killer is whoever shares that room.
- On lying-killer days, test each suspect as the liar — only one choice leaves a valid board.
A murder sudoku gives you a floor plan, a handful of suspects and one statement from each of them. Place everyone — one person per row and one per column — and the killer is whoever ended up alone in a room with the victim. Simple rules, but a blank 7×7 plan can still feel like a wall. These techniques are the ones we use when we test every case.
Room for Murder Daily
A new floor-plan murder mystery every morning: place the suspects, find who was alone with the victim. No sign-up, works on phones.
Play today's caseThe basics (Easy days)
1. Start with the tightest statement
Read all the statements first, then rank them by how many squares they allow. "On the bed" in a room with one bed is a single square. "In the kitchen" might be nine. Place the tightest one and the board starts to collapse.
2. Cross out the row and the column — every time
This is the sudoku part, and it is where most mistakes happen. The moment someone is placed, strike their whole row and column. On a phone, use the ✗ marks: long-press a square.
3. Remember what you can't stand on
Tables, plants, shelves, stoves and the piano block their squares. Chairs, sofas, benches, beds, bathtubs and rugs don't — people sit and stand on them. "Beside" means directly next to it — up, down, left or right, never diagonally — and a two-square sofa has more neighbours than a lamp.
4. Corners are rare
"In a corner" means a square touching two walls of the person's own room. A room has only four of those, and furniture often blocks one or two — so corner statements are excellent starting points, especially when the room is named too.
The middle game (Medium and Tricky)
5. Room capacity
A room that is two rows tall can hold at most two people, however wide it is. A room one column wide can hold only one. When a statement says two suspects are in the same room, capacity often tells you which room.
6. "Alone" cuts both ways
If a suspect was alone, nobody else is in their room — so every other suspect's options shrink too. And the victim's room always holds exactly two people at the end: the victim and the killer.
7. Direction clues are row and column clues
"North of Tom" means any row above Tom's row, not just the square above. Once Tom is placed, a north-of clue crosses out every row from Tom's downwards.
8. Look for the last free square in a row
When a row has only one square left that isn't crossed out, blocked or illegal for anyone remaining, someone must stand there. Ask: who is still allowed in that square? Often only one suspect is.
Expert days (Hard)
9. Pairs and pigeonholes
If two suspects can only be in the same two columns, those columns are "taken" — nobody else can use them. This is the murder-sudoku version of sudoku's naked pair, and it unlocks most Saturday cases.
10. Merged rooms change the count
L-shaped rooms span more rows and columns than they look. Count them again before you use capacity: an L-room can sometimes hold three people.
11. Save the victim for last
The victim rarely has a statement of their own. Place everyone else; the victim drops into the only square left, and the killer is whoever shares that room. If two people share it, re-check — the rules say the killer was alone with the victim.
Sunday: when the killer lies
12. Test each suspect as the liar
On a lying-killer day, exactly one statement is false: the killer's. Pick a suspect, assume their statement is the lie (so the opposite is true), and solve. If the board breaks — two people forced into one square, or nobody alone with the victim — that suspect wasn't the liar. Only one choice survives, and it also tells you who did it.
Practice routine
Play the daily case for a week from Monday to Sunday: the difficulty climbs on purpose, so each day uses one more of these techniques. Missed a day? The archive keeps every past case, and solving one late still counts towards your streak.
Room for Murder
80 floor-plan murder mysteries in five chapters, from cosy cottages to a lying-killer finale — the book behind this site.
Solo or together
See it on EtsyQuestions people ask
What is the fastest way to start a murder sudoku?
Find the statement that fits the fewest squares — "on the armchair", "in a corner of the kitchen" or "beside the stove" — and place that suspect first. Then cross out their row and column before you read anything else.
Do you ever need to guess?
No. A well-made murder sudoku has exactly one solution that can be reached by deduction alone. Every case on Room for Murder Daily is checked by a solver that proves this before it is published.
How long does a murder sudoku take?
A 5×5 case usually takes 3–8 minutes. A 7×7 case with merged rooms takes 10–25 minutes, and a lying-killer case a little longer, because you test each suspect as the liar.
What is the difference between a murder sudoku and a logic grid?
A logic grid matches categories in a table (who had which weapon, in which room). A murder sudoku puts people on a map, so the clues are spatial — beside, north of, in a corner, alone — and the final room tells you the killer.
Keep reading
- The 10-Minute Habit — Why a Daily Logic Puzzle Is Worth Keeping (and How to Keep Your Streak)
- Daily Puzzle Games Like Wordle — for Logic Lovers
- What Is a Murder Sudoku? Rules, Tips and Where to Play
We make the games mentioned in this guide — that's why we know them well. Links to Etsy go to our own shop, Midnight Motive.