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.
Revealing mistake: Doug has the hologram when inside the alien nuclear reactor, and a bunch of bad guys encircle the holographic image and fire at it at point blank with automatic weapons, and not one bad guy gets hit. If they encircled the 3D image, at least a few bad guys would have been hit by their own men. (01:37:00)
Revealing mistake: When Arnie uses the dead body as a human shield, watch the corpse's mouth - he grimaces every time he gets hit (the squibs hurt). (00:31:00)
Other mistake: In the scene after Arnold kills the construction hoods he goes home to Sharon Stone and tries to convince her that it was real by showing her his bloody hands with which he was grabbing her shoulders, yet there is no blood on her or the appliances he turned off upon entering the apartment.
Revealing mistake: Pay attention to the drywall on Quaid's left just as he exits the bathroom to a rain of gunfire. If you look closely there are discolorations in the paint where explosive charges are packed and set to detonate in lockstep with the shots - creating "bullet holes". (00:25:00)
Plot hole: When Arnie is taking off his woman's head he presses a switch by the ear and the ear comes out. The device reaches right inside the fake head and there would be no room for Arnie's real head. (00:46:00)
Continuity mistake: A few minutes before Quaid kills his "wife", there's a shot of her with bright pink lipstick. Immediately before he shoots her, her lipstick is burgundy. (01:03:10)
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)
Revealing mistake: In the scene where Sharon Stone attacks Arnie in their house with a knife you can see that the knife is a fake because it bends. (00:26:00)
Continuity mistake: When Arnie is giving his info about what his Mars woman should be like, there are two things to look at on the screen in front of him: The screen zooms in on the woman's face, cuts back to Arnie, cuts back to the screen when it zooms in on the face again. Also, look at the sequence when he's selecting her personality: "demure" is lit up before he mentions it. (00:17:35)
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: In the escalator scene when Arnie uses a corpse as a shield, there's a close-up of Arnie's gun firing, and we can see there's blood on the side of the corpse's head. However, in the wider shots there isn't. (00:31:00)
Continuity mistake: When Sharon Stone cuts Arnie's left arm with the knife, he starts bleeding. Right afterwards he grabs Sharon's neck with his wounded left arm. When he lets go, Sharon's neck has no blood stains from Arnie's wounds. How come? (00:26:10)
Revealing mistake: When Quaid throws the bullet-ridden body down the escalator, you can see Richter and Helm have both been replaced by stuntmen. Their hairstyles are totally different. You can also see that the 'dead' man is still alive as he's flying through the air (slow motion helps). (00:29:55)
Continuity mistake: In the scene where Michael Ironside's cronies are dragging Arnie to the service lift, watch Arnie's head: It changes from being flexed forward to being extended backwards as they swap camera angles. His hand positions change as well from shot to shot. (01:06:40)
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 Arnie meets Bennie, he takes him to his cab and opens the door for him to get in. At that time, there's an explosion, and Bennie pulls the door down to shield himself and Arnie. The camera switches to behind them, and Bennie is just now pulling the door down. (00:52:50)
Revealing mistake: When Arnold jumps through the glass, you can definitely see a change in his face and body shape. (From the stuntman). (00:30:05)
Other mistake: The title 'Publicity' is misspelled as 'Publicty' in the end credits. (01:46:30)
