Friday The 13th (1980) - 49 mistakes

Revealing: In the beginning, Claudette and the other counsellors are all singing. When they get closer you can see that Claudette is playing the guitar, then she stops, but the guitar playing and singing still continues.

Visible crew/equipment: When Annie jumps from Mrs. Voorhees' jeep, a white elbow pad can be clearly seen on her right elbow.

Revealing: When Ned is pretending to drown, Brenda swims out to rescue him. You can clearly see that she and Ned stay underwater for a few second, until their cue to emerge.

Audio problem: When the kid is playing classic guitar the movement on the guitar's neck doesn't match the music. He somehow manage to play high tones on low frets.

Continuity: When Alice opens the pantry door to find Crazy Ralph in there, you can see Ned and Nancy running to the kitchen. It cuts to Ralph, then back again and the other two run into the kitchen again.

Continuity: At the lake when they pull the floating object by the pier the girl on the right side is about ten feet ahead of the object. When it cuts she is behind it.

Continuity: When the two teenagers find the axe in the bed, the axe is perfectly clean despite the fact it had been shoved through a girl's head. Furthermore, it also looks brand new with a fresh coat of polish on it as well.

Continuity: When the kids are at the beach, Alice shows up saying "Hey you guys. Ready to get back to work?", while placing her foot on a red towel. When it cuts the towel has changed position.

Continuity: When Annie talks to the dog, it's position changes between shots.

Continuity: After Brenda is thrown through the window, he face is facing to her right. Later when Alice goes back to the kitchen, her face is facing to her left. The glass and wood around her changes too.

Visible crew/equipment: In the scene at the diner after the kids have played "Strip Monopoly" there is a shot of Sandy behind the counter and some customers walking out of the diner. Look behind the last woman walking out and you can see a crew member reflected in the window.

Continuity: When Enos is about to give Annie a lift he says "Ok kid, let's move", we see the red clothing going over her shoulder covering her bag's strap. When it cuts the strap is visible.

Continuity: After Alice bangs at the lock with the end of the gun, the position of the lock and it's chains differs through the following consecutive shots.

Continuity: When Alice runs into the barn to hide from Pam, as she slides the door open, a plank of wood falls over, to the right of the door. In another shot of the barn, it is upright again.

Revealing: When Jack and the kids get up to the cabin you see Steve chopping on a stub in order to remove it. He then gets help from the kids to tip it over but there are no chop marks on it.

Continuity: While Annie is talking to the woman in the bar the guy that washes the floors (that appeared earlier standing on the other side of the counter) now stands behind the counter by the woman. When Annie is leaving the guy stands on his original position.

Deliberate "mistake": In the scene when Alice decapitates Mrs. Voorhees and Mrs. Voorhees raises her hands and grabs air, if you look carefully, the hands have hair on the back, even when, during the chase scenes, she doesn't have hair on the back of her hands.

Continuity: After Brenda hears a noise, she puts her book down next to the candle, and walks to the door. When she gets to the door, the book is now by the opposite side of the candle.

Continuity: As Annie backs into the tree, and then has her neck slit, her hair changes styles between shots, and the amount of leaves in her her changes as well.

Visible crew/equipment: When Pamela Vorhees pulls over to pick up Annie we can see a man's arm reflected in the front shield sitting in the passenger seat.