Goofs

When Alicia is underneath the stage trying to get the key, the gun in her hand changes from an automatic pistol to a revolver in one shot - and then back to the automatic.

In the shower scene, after Alicia wakes up, the shower curtains are shown closing, but then they suddenly move; they are clearly two separate shots.

In the scene where the girl is cut in half, it is later revealed she was cut in half by a chainsaw. However, as this was happening, there wasn't single noise coming from the chainsaw.

It's obviously a dummy when the girl get torn in two pieces in the attic. When her torso lies on the floor and the guy next to her stands up, he kicks it by mistake. It then moves very easy and doesn't seem to be heavy as a human body (or half a human body).

Peter's "severed" head blinks several times during the final sequences.

When Alicia is removing the key from the stage floor, the close-up shot of the key and nail, for a few frames, you can see a hand (crew member) trying to dislodge the key.

In the security office, there are two copies of the exact same issue of Time magazine - one in the drawer and one on top of the desk.

When Alicia uses the Fire Extinguisher on Irving Wallace, he falls and grabs a power cable to climb back up. In the wide shot of Irving Wallace climbing back up, in the far right corner of the frame, you can clearly see a cable, hoisting him up as he climbs up the cable.

The old man tells Alicia that her Browning Hi-Power pistol would not fire because the safety catch was engaged. Later, he says that all Alicia had needed to do is load a round into the firing-chamber. On the Browning Hi-Power pistol, releasing the safety catch does not load a round into the firing-chamber.