A family tree of useful constraints
Classic sudoku asks which number belongs in each square. Its strength comes from a small set of rules interacting across a large grid: one of each number in a row, column and box. Killer sudoku adds cages and arithmetic, giving the player another system of constraints to reconcile.
Logic-grid puzzles approach the same pleasure from another direction. They describe relationships in language: the baker arrived before the doctor; the blue house is not beside the park; Nora owns neither the bicycle nor the cat. Solving means translating those statements into eliminations until every category lines up.
Murder-mystery deduction games add motive and atmosphere, but their logic is sometimes hidden behind dialogue choices or object hunts. Detective Sudoku keeps the deduction on the surface. The floor plan is the grid. The statements are the clues. The final room identifies the culprit.
These traditions fit together neatly. Rows and columns prevent duplicate placements. Rooms and furniture make the board a location rather than an abstract square. Natural-language clues give every suspect a voice. The murder rule makes the solved arrangement mean something.
What makes this whodunit different
The game is inspired by classic deduction grids, but it does not ask you to fill a separate spreadsheet of attributes. You place the suspects directly into the scene. A statement such as “I was north of Grace” can be tested against the same board that contains Grace, the study wall and the victim.
Two promises keep the mystery fair.
First, every case has exactly one solution. The generator does not stop when it finds an arrangement that works. A constraint solver searches for another. If a second answer exists, the clue set is strengthened or the case is discarded. The mystery reaches the player only when one complete placement survives.
Second, hints explain the deduction. The solver records the steps it used: which clue ruled out which positions, where a row became forced and how a relationship tightened after another placement. When you request help, the game presents a real next step with its reason. It does not silently reveal a square and leave you to reverse-engineer the logic.
How a case is assembled
Each case begins with a room template: walls, named areas, furniture and occupiable cells. The generator places a cast of suspects, chooses a victim and builds a pool of clues that are true for that hidden solution. It then selects clues for the characters and asks the solver how many arrangements remain.
If the answer is more than one, the weakest part of the evidence is revised. A vague clue may become a stronger one, or a suspect may receive a compound statement. The loop continues until the solution is unique. Cases that collapse into an uninteresting run of obvious placements are rejected as well.
The launch collection is planned around 75 cases. “Generated” here does not mean endless random noise. It means the system can test many casts and clue combinations, keep the coherent ones and grade them by the actual reasoning they demand. The cases are packaged with the app and work offline.
Difficulty measured by technique
Many puzzle games use board size or a timer as a rough proxy for difficulty. Detective Sudoku watches the solve itself. A straightforward case may fall to direct clue eliminations and single remaining positions. A harder file may require relational pruning, hidden singles, pairs or a longer chain involving the murder constraint.
That produces a more honest difficulty label. A small board can be devious. A large one can be gentle. What matters is the depth and variety of deductions between the first clue and the closed case.
If you enjoy games like killer sudoku, deduction puzzles on iOS, or a compact whodunit that respects your reasoning, Detective Sudoku sits at their intersection. It is still sudoku in its discipline. It is a mystery in what the final grid reveals.