The main character, whose name is later revealed to be Mike Schmidt,[4] has started a job working as a night watch security guard at the restaurant Freddy Fazbear's Pizza (a pastiche of restaurants like Chuck E. Cheese's).[3][5] A voicemail message left by Mike's predecessor explains that the animatronic animal characters used at the restaurant are able to roam freely around it at night, because if they were left off for too long, their servo motors would lock up. He also adds that the characters were no longer allowed to roam freely during the day following an incident referred to as the "Bite of '87", which apparently involved the loss of someone's frontal lobe. The employee warns the player that if one of the robots encounters a human, they will automatically assume that it is a robot that is not in costume yet, and "forcefully stuff them" into a spare mechanical Freddy Fazbear costume, killing them in the process.[6]
Newspaper clippings in the background of one of the scenes reveal that the restaurant was site to the disappearances of five children whose bodies were never found, after a man dressed as one of the animatronics (in the Golden Freddy suit) lured them into a back room, and was said to have murdered them. Later, the restaurant received complaints that the animatronics began to smell foul and became stained with blood and mucus around the eyes and mouth, with one customer comparing them to "reanimated carcasses".[7]