Suspect was one of the interactive fiction games produced by Infocom, Inc during the 1980s. The reader/player is the main character in a detective story. The reader is a reporter attending a high society costume ball when the host of the party is found dead. The story has a life of its own, with several different outcomes possible depending on the activity of the detective. If the player remains passive and does not try to solve the murder, eventually evidence will point at the reporter, who will be arrested when the police arrive.

The fiction came in a cardbox box containing the floppy disk and printed clues that were needed to successfully solve the game. These clues were known as "feelies" and provided an effective protection against illegal copies of the game (in a time when photocopies and scans were not so common). Suspect's feelies included a magazine article, a receipt for a costume, and a business card. Within the terms of the story, these were all said to be in the pockets of the detective.

The game illustrates how interactive fiction could go beyond the limits of other text adventures like Zork or Adventure. The story of the game developed from a combination of programmed events (people wander in and out of rooms, a killing occurs, several people meet in secret) which occur whether the player is aware of them or not. If the reporter does not seek out the clues and attempt to witness the events, s/he will be caught up in them. By taking an active role in the story, the player gains agency and can control events to some degree (at one point in the story, if he is in the living room, two suspects will leave immediately instead of having a planned tryst). The story takes place in 57 rooms, within spaces that include a Mansion, a garage and the surrounding grounds. Players can interact with the story using a programmed vocabulary of 674 words, allowing a wide range of interactions with what the Infocom team have described as the "dungeon master" of their works.