How we know the case is fair
Every case is proved solvable before you see it
The obvious way to build an AI detective game is to let the AI invent the mystery as you go. It is also the way you get a case with no answer in it — where the contradiction you were chasing was never there, and the game quietly agrees with whoever you accuse.
So Culprit does the opposite. The truth, the timeline, the evidence chain and who knows what are authored and fixed. Then a scripted detective — no hints, no luck, no co-operation from the AI — plays the case and has to reach the right accusation. If it cannot, the case does not publish.
The current table
Generated at build time from the same gate that decides whether a case may ship — not typed out. If a case stops passing, this page says so on the next deploy.
| Case | Solvable | Fair-play rails | Structure | Depth | Publishable |
|---|---|---|---|---|---|
| The Empty Frame | ✓ | 12/12 | ✓ | ✓ | ✓ |
| Death at the Gilded Lily | ✓ | 12/12 | ✓ | ✓ | ✓ |
| Death at the Gilded Lily — After Dark | ✓ | 12/12 | ✓ | ✓ | ✓ |
| Meeple and Murder | ✓ | 12/12 | ✓ | ✓ | ✓ |
| The Prize Marrow Affair | ✓ | 12/12 | ✓ | ✓ | ✓ |
| Murder at Ravenshollow Manor | ✓ | 12/12 | ✓ | ✓ | ✓ |
6 of 6 cases pass every check
The 12 rails
Each one is a way a whodunnit can be technically complete and still unfair to play.
- culprit hides something
- The culprit must be holding at least one fact they will not volunteer. A guilty party with nothing to conceal is not a mystery, it is a queue.
- decoy motives
- More than one suspect must have a motive worth having. If only one person could plausibly have wanted it, the case is arithmetic.
- lies catchable
- Every lie must be contradicted by something reachable — a document, a room, or another suspect's account. A lie you cannot catch is just the game withholding.
- motive establishable
- The real motive must be provable from what a player can find, not merely announced in the epilogue.
- no filler suspects
- Every suspect must carry something: a secret, a contradiction, or a piece of the timeline. Nobody is in the room to make the number up.
- red herring exists
- At least one honest-looking trail must lead somewhere else. Without it the first suspicion is always right.
- rooms earn their place
- Every room must hold something worth finding. A room you can search for nothing is a corridor with a name.
- rooms two way
- The map must not trap you. Every room you can enter, you can leave, by a route you already know about.
- stall hints
- A player who has stopped making progress must be able to get unstuck without being told the answer.
- timeline reconstructable
- The order of that evening must be recoverable from testimony and evidence alone — no gaps only the author can fill.
- unlock threshold
- The accusation must unlock at a point where the case is genuinely provable, not the moment you have merely seen enough screens.
- winnable without confession
- You must be able to win without anybody breaking down and admitting it. A case that requires a confession is a case that requires the AI to co-operate.
Questions
- Are Culprit's cases AI-generated?
- The suspects are played by AI actors, but the case itself is authored and audited. The truth, the timeline, the evidence chain and who knows what are all fixed before a case ships, and a scripted detective has to be able to solve it. What the AI improvises is delivery — hesitation, deflection, an outright lie — never the facts.
- Can a suspect invent evidence or change their story to something impossible?
- No. Each actor is given only the facts their character is allowed to know, and cannot introduce a new room, a new person or a different solution. They can lie about the facts; they cannot replace them.
- What does 'proved solvable' actually mean?
- A scripted detective — no hints, no luck, no help from the AI — plays the case and must reach the correct accusation with the evidence required. If it cannot, the case does not publish. That check runs on every case in the table above.
- What happens if a case fails one of these checks?
- It is not published. The same gate runs on commissioned cases, so a mystery written from your own brief is held to the identical bar before you can play it.