Continuity mistake: When Arnie uses the hologram projector in the alien reactor, there is a brief shot of him facing his own hologram image. Note that the gun and the projector switch positions in Arnie's hands - the bloodstain on his shirt's sleeve does not. (01:37:55)
Continuity mistake: When Arnold Schwarzenegger and Rachel Ticotin are being attacked by the giant drilling machine, Arnie grabs a pneumatic drill and cuts the main oil line of the machine, getting the left side of his face and his shirt doused in oil. Yet throughout the remainder of the film, there is no oil on Arnie's face or shirt. (01:39:55)
Continuity mistake: Soon after the woman costume malfunctions, you can see the blue screen through the windows, which in the next shot is coloured orange.
Continuity mistake: When the man delivering the briefcase calls Quaid and tells him to go to the window, you see on the screen he turns to look to his side, but when Quaid goes to the window the man on the phone is still looking straight and then is seen turning to his side again.
Continuity mistake: When Quaid first arrives at The Last Resort, he hands Benny a tip and walks in through the front doors. In a front shot behind him is the head of a man outside who wasn't there a moment before when Quaid walked in.
Continuity mistake: When Quaid uses the hologram, it's a mirror image of himself. However, before he enters the reactor room full of guards, we see him put the hologram device on his left wrist. His hologram (the one all the guards shoot at) has the device on his left wrist as well, instead of what would be the right.
Continuity mistake: In the apartment, Lori grabs a knife, and after the first slice, switches the knife to her right hand. After the second slice, the knife can be seen midair as she tosses it from left to right again.
Suggested correction: It's not being shown tossed from right to left, you just see her spin the knife in the air to hold it in a different position.
Continuity mistake: Arnie has come back to the apartment after shooting his coworkers and asks Lori if this is a hallucination. He then reveals fresh blood smeared all over the palms of his hands but he had grabbed her before he asks the question. Lori is sitting in front of him without a drop of blood on her.
Continuity mistake: When Quaid takes off his old woman disguise and throws the head to a soldier who catches it, the close-up shows that he's holding it beneath the ears. In the wide shot, he's holding it from behind the skull.
Continuity mistake: After Edgemar lets Lori in and closes the door, a moment later the door is open in the mirror's reflection.
Continuity mistake: As Quaid copies the name Melina on the paper, the writing is in heavy black ink. When he leaves the counter the writing is very light, nearly non existent.
