Shadows of Doubt

A huge generated city of citizens makes the culprit impossible to guess. Shadows of Doubt generates hundreds of citizens in seconds, each with a home, a job and fingerprints, and one of them is the killer. Because the information space is so large, the detective work is choosing the best path through it, and you only find the culprit by choosing where and when to go.

In the example, a type BD fingerprint on a toy car leads through CCTV, co-workers, a resident database and a door handle to a shotgun and Oscar Nielsen. Generating citizens supplies the dead ends and red herrings that would be expensive to author by hand. Mark Brown: "You can't guess that."

Players follow leads by learning how the city is structured, and several routes reach the killer. Every home has a box holding the occupant's birth certificate, and CCTV footage and work schedules show when to look or break in. You can trace the killer through footprints, fingerprints, CCTV or phone call history, so no single clue blocks progress.

Brown groups this with Return of the Obra Dinn's multiple ways to deduce an identity and Hypnospace Outlaw's hidden server: games reward learning how the world is organised.

A pinboard and a killer who strikes again keep the investigation manageable. The pinboard lets you place people, places and objects, connect them with string and add notes. Brown says it makes investigations "10 times more fun".

Hints also come from the game itself: the killer strikes again, which gives new leads when you are stuck.