Continuity mistake: There are many holes in the 'squad structure' once the marines arrive at Hadley's Hope. Gorman calls up 1st Squad (comprised of Apone, Vasquez, Crowe and Hudson) to approach the colony first. They do. But, if you look closely, there are other marines present. When they arrive at the door Apone goes straight to the console, Hudson holds back to our left and Crowe rests in the background on the right of the screen. Apone then calls Hudson up to do a bypass. If you look closely as Hudson runs up to the console you will see Frost in the background, he steps up to the left of Crowe (his left) and on the left of the screen, you will see Wierzbowski crouch with his flamethrower, slightly obscured by Vasquez (look between her legs). Then 2nd squad is called up. It is comprised of Hicks, Dietrich, Drake, Frost and Wierzbowski. Watch the shot of Vasquez entering the lock and you will see Frost standing roughly where he was when the 1st Squad ran up. Clearly the original scene had all the marines descend on the North Lock simultaneously. The confusion continues when Gorman, Ripley, Burke and Bishop enter the South Lock. They meet up with Hicks' squad yet Dietrich and Wierzbowski are curiously absent.
Continuity mistake: When Ripley and Hicks are discussing their defence plans after the first encounter, they decide to put one of the auto guns in each of three locations, leaving one left over. When we see the guns in place they have actually used two guns in each of two locations, that is, two pairs.
Continuity mistake: Director's Cut: During the briefing scene on board of the Sulaco, Lt. Gorman begins the briefing. He gets interrupted by Hudson. Before the shot changes to Hudson, you can see Gorman standing straight in front of the marines and looking straight ahead. In the shot from Hudson, you can see Gorman looking to the right to face Hudson. He still should be looking straight ahead.
Continuity mistake: As the marines first enter the med labs, Drake at the front, there are some neon tubes hanging from the ceiling that slowly rotate to face the camera. As the angle changes and Drake goes round a corner, the neon tubes rotate to face where the camera previously was again in the background.
Continuity mistake: When Gorman and Burke come to see Ripley to persuade her to come to LV-426, Burke hands her a plastic card so she can call him if she changes her mind. At this point Ripley lights a cigarette. The scene then cuts to a view of the whole room, and Ripley can be seen lighting the cigarette again.
Continuity mistake: When Ripley and the marines go to where the colonists are, there is a ladder in front of the vehicle that was driven inside; the ladder would be in the way if the vehicle was driven further in. But when all hell breaks loose and Ripley decides to drive the vehicle further in, to rescue the marines, the ladder is gone - in fact, a lot of things look different the second time round.
Continuity mistake: Just before the marines are extracted, Hicks tries to close the APC door. An alien stops the door and tries to get inside. Hicks picks up his shotgun and jams the muzzle into the alien's mouth and fires, killing the alien. The alien falls away, they immediately close the door and the APC begins to back up. The camera shot changes to an outside view of the APC. If you look at the area as the APC backs up, you'll see falling debris but no dead alien. It's doubtful the marines would've pulled it into the APC as we don't see it again, or that they would've kicked the corpse out really far due to the acid.
Continuity mistake: When the marines first encounter the Alien hive in the reactor, and Ghorman asks Hudson what he's seeing, we're treated to a shot of Vasquez' helmet cam, and her name in the bottom right is missing her first initial. [Timecodes are from the special edition of the movie. The first one is the one for the error, and the second is a different scene with the initial present for comparison.]
Continuity mistake: In the scene close to the end of the film when Ripley is getting the weapons ready in the 2nd drop ship to rescue Newt, she slams in a new ammo clip into the pulse rifle and the counter reads 95 rounds. Moments later when she is in the elevator descending into the aliens lair the counter is reading 42 rounds, even though she hasn't fired a shot.
Add timeken shabby
Continuity mistake: Towards the end of the film where Ripley and Bishop are in the dropship flying towards the atmosphere processors, Ripley begins to build a composite weapon from a flamethrower and a pulse rifle. She pulls a flamethrower from a rack on the wall, but lays pulse rifle on the deck of the ship, and then pulls a pulse rifle from the rack and lays a flamethrower on top of the pulse rifle.
Continuity mistake: In the scene where the drop ship is about to leave the main ship look at the picture on the side of the ship, just to the left of the pilot's window. There is a symbol of an eagle. Note which way it is facing. Later when the ship is on the planets surface and the marines are leaving it, the eagle is facing the other way.
Continuity mistake: In the original "Alien", Ripley dons a space suit in the shuttle, in preparation to decompressing the quarters to the hard vacuum of space. The helmet has no light on its top. Subsequently, in "Aliens", the opening shots pan through the shuttle chamber, and Ripley's helmet sits there...with a light on its top.
Continuity mistake: Right after Ripley is rescued from the Narcissus, look at her hair in the clinic. At first there is a wide angle shot of the nurse coming over to her with some small talk. Then, when the shot changes to a close up of Ripley and the nurse, her hair has puffed out about 2 inches more.
Continuity mistake: In the extended edition of the film, Ripley, Gorman, Burke, and Bishop meet up with Hicks at the entranceway. It is raining heavily and Ripley's hair gets soaked. But when she is inside a few minutes later, it looks as if she has had time to dry her hair thoroughly between now and then.
Continuity mistake: When Bishop is doing his knife trick on Hudson, his hair changes significantly from one shot to another, especially on the top and around the ears. In addition, at the end of the scene, Hudson is given a meal that was taken off a heater nearby on the table. That meal was apparently not placed back for some of the closeup shots, as it is missing from the heater. Finally, the time shown on Bishop's wristwatch seems to change radically about half-way through the scene.
Add timeMan Athan
Continuity mistake: Hicks gives Ripley a wristwatch which is linked to his tracker. If you look at the watch, its face is mostly black with a tiny portion that is clear. However, when Newt has the watch and falls down the tunnel and is wandering around the pool of water before Hicks and Ripley find her, you can see that the watch face has no black - it has a full clear face and appears to be a standard digital watch of the 1980's era.
Continuity mistake: When Ripley is driving the APC, the passenger side front tire is on fire and engulfed in flames. When she runs over the alien with the same tire, the flames are completely gone. In the next shot and several shots after, the tire is completely engulfed in flames again.
Continuity mistake: As the ship carrying the marines to the planet where communication has been down for too long, the pilot of the ship says, "Where's the damn beacon? Oh, I see it." But when she says the last bit, there is no vision of the beacon; it only comes into sight a few seconds later.