Five Nights at Freddy's, also known as FNaF, is a horror-themed logic-puzzle game. Freddy Fazbear's Pizza, a family-oriented pizza restaurant, needs a security guard. The player works as a new guard between midnight and 6 a.m. during the night shift. They must watch out for intruders and check on the animatronic animals designed to entertain children during the day. The animatronics (Freddy, Bonnie, Chica and Foxy) sometimes activate automatically, lurk around the building and attack intruders and criminals.
The animatronics also attack security guards. The player must anticipate attacks using the security cameras and defend against the animatronics by dropping two heavy metal sliding doors into place, switching on lights and paying close attention to vents. The player receives limited power every night. To prevent total power depletion, they can't keep the doors closed, use the lights or check the security cameras all the time.
Five Nights at Freddy's challenges the player to find the right combination of actions to prevent the animatronics from attacking or killing them. The player must use both visual and auditory cues. For example, they must look for signs that the animatronics are wandering the restaurant, such as glowing eyes and shadows on a floor or wall. They must also listen for changes in normal sounds and new sounds like footsteps or running noises.