This article covers all the known goofs in the Alien films.
- Brett's cigarette changes in length when Ripley confronts him about always answering with, "Right."
- When Dallas enters MU-TH-UR, the shot from outside the interface room shows that one of the lights around the doorway is not illuminated (the fifth one down from the ceiling). In the following shot from inside the room, it is suddenly working. The exact same thing happens when Ripley enters MU-TH-UR later in the movie, meaning these two scenes must have been shot at the same time.
- Following the pull back view of the Derelict, a panoramic view of the ship's landing area (with the Nostromo's lights visible through the wind-borne debris) shows the ringed planet Calpamos in the sky. However, there were no rings around Calpamos during the approach in space.
- When Dallas, Kane and Lambert are exploring the alien spacecraft, you can see that there are wipe marks inside their helmets that change between shots, most noticeably on Kane. This is because the helmets were built without sufficient exhaust systems for the actors and would steam up, but in reality, the characters wouldn't be able to wipe the inside of their helmets with them on, and they couldn't possibly remove them to wipe them due to LV-426's inhospitable atmosphere
- When Dallas, Lambert and Kane first discover the Pilot, the room is sufficiently illuminated for the Pilot, the device he is seated on and the surrounding floor to be perfectly visible. In all close shots, it's suddenly pitch black and all that can be seen are the small areas lit by the crew's helmet lamps.
- Kane is wearing a beige leather hood inside his space suit on LV-426. However, when his helmet is cut off aboard the Nostromo, the hood has vanished.
- When Dallas uses the pen to catch the acid blood, it melts the top of the pen to the point where it is deformed and smoking. When he hands the pen back to Brett, the top of the pen is no longer deformed at all, but it's still smoking.
- When the dead Facehugger falls onto Ripley, it lands on the floor with its legs up. The distant shot shows that its tail has looped under its body, but the close-up shows the tail laid out straight, away from its body.
- Kane's shirt changes between being tucked in and hanging out during the Chestburster scene.
- When the Chestburster erupts from Kane, the camera changes angle and there is significantly less blood on his shirt. Then when the angle changes again, the blood comes back.
- When Brett is demonstrating the cattle prod weapon for the first time, the spot he touches on the overhead has a burn mark before he touches it, likely from a prior take.
- The motion detectors used in the film often fail to pick up the movement of nearby crew members. Furthermore, the devices initially emit a high-pitched humming when they register movement, as heard when they are first tested and when Ripley, Parker and Brett mistakenly detect Jonesy in the locker. However, when Dallas is in the air shafts later in the film, the devices instead issue a completely different beeping tone.
- Just before Dallas is taken, he touches a patch of Xenomorph slime on the floor. In the next shot he has more slime on his hand than there was on the floor to begin with. The amount of slime on his hand also changes between shots.
- When attempting to flee from the Alien inside the air ducts, Dallas descends a ladder and clearly is not carrying his flamethrower. When he gets to the bottom of the ladder, he has it again.
- Just before Dallas is taken, Ash's headset disappears.
- When Ripley is inside MU-TH-UR, the writing on the readout screen is projected onto her face. The screen she is looking at has four lines of green text, yet the image on her face is of one line of white text.
- Ash suddenly appears beside Ripley in the MU-TH-UR interface room, even though we never heard the door (which makes an audible hissing noise) open.
- When Ripley tries to escape from Ash, she suddenly has a nosebleed for no reason. This was actually supposed to tie in to an earlier scene where she suffers a decompression injury, but that sequence was cut from the film.
- The milky sweat that runs down Ash's forehead before he attacks Ripley disappears without him wiping it away.
- During Parker's fight with Ash, the sleeve on Parker's right shoulder suddenly becomes torn and a safety pin is visible holding it together. In the next shot we see his shirt intact and we see Ash tearing it. The positions of the various characters also vary wildly from shot to shot after Ash has been beheaded.
- The items on the table behind Ash's severed head change position between shots.
- When Ripley reconnects Ash, the switch from dummy to actor is blatantly visible. When the android is incinerated, the switch back to the dummy head is equally noticeable, and Ash's left arm also disappears.
- After Ash's body is incinerated, the interior walls of the Nostromo appear more metallic and grey than they were before. According to director Ridley Scott, this was done intentionally to make the Alien's presence appear more menacing.
- Parker's skin color changes in the extreme close-up of the Alien's inner jaw smashing his skull, and he also appears to be bald. This is because a melon was used to simulate the impact. The shot lasts only a split second, but the difference is still noticeable.
- The Alien's tail snakes between Lambert's feet before it kills her, but it's not her feet that are shown — Lambert wears cowboy boots, yet the feet on-screen are dressed in sneakers. The surrounding floor also changes. The shot is in fact of Brett's legs, as the footage was taken from his death scene, which was originally longer and featured the Alien lifting him up with its tail.
- When Ripley is trying to set the self destruct aboard the Nostromo, the sequence begins before she activates the fourth and final button on the control panel.
- The rods that rise up out of the self destruct mechanism switch between being up and down from shot to shot when Ripley tries to deactivate the countdown.
- After Ripley fails to cancel the self destruct we see a shot of the countdown clock showing about 4 minutes 50 seconds left to destruction. Following a shot of Ripley, there is another quick shot of the countdown clock, now showing 10 minutes 39 seconds left to destruction, even though detonation was supposed to happen just 10 minutes after the countdown was first initiated.
- MU-TH-UR's two 30 second countdowns take 36 and 37 seconds respectively.
- It can be seen multiple times throughout the film's final act that Jones is not in the carry box. This is most obvious when the front or back of the box is toward the screen when Ripley is moving through the corridors.
- When Ripley backs into the shuttle's closet there three axes on the wall next to her. When she starts to get into the space suit there are only two, then when she puts the helmet on there is only one.
- The two "knobs" on the front of the space suit helmet Ripley wears are sealed when she is inside the locker, but when she is in the shuttle's cabin the knobs are open at the bottom.
- In the shuttle, Ripley presses buttons to release steam or gas onto the Alien. During the first two bursts of steam (which miss the Alien), the inside of her helmet is foggy and streaked. After the Alien reacts to the third blast of steam, the inside of Ripley's helmet is suddenly clear.
- When Ripley shoots the Alien with the harpoon gun, its acidic blood should quickly melt the harpoon and/or its cable, releasing the creature, yet it does not.
- A dippy bird is seen on the table in the mess hall throughout the film. Dippy birds require water to drink, otherwise they will not move. However, the bird is moving when the crew first wakes up, even though they have evidently been asleep for some time (they are in an unknown part of deep space, 10 months away from Earth). As a result, any water in the beaker should have evaporated a long time ago and the bird should be motionless.
- Several times in the film, the data being shown on computer screens is seen projected onto the faces of the crew. It would be impossible to read a screen that bright.
- LV-426 is said to be 1200 km in diameter and have a surface gravity of 0.86 G. For a moon that small to have a gravity of 0.86G, it would have to be more than twice as dense as the densest element known to man, osmium. Its surface would also be visibly curved when standing on the ground, which it clearly is not.
- One of the moons in the system containing LV-426 is out of phase with the others.
- During the landing sequence, Kane issues the instruction, "Roll 92 degrees port yaw." Roll and yaw are two entirely different directional axes in flight and would never be combined.
- MU-TH-UR issues several basic grammatical/spelling errors throughout the film. When Dallas first queries her at the start of the film, "ALIGNMENT" is misspelled "ALLIGNMENT". Later, it states Special Order 937 is to "INSURE" the safe return of the organism. The correct verb would be "ENSURE". Also, messages typed by the crew are supposed to be underlined, while messages from MU-TH-UR are not. However, this arrangement goes awry.
- When the crew ejects Kane's body into space, it begins to flip faster and faster as it moves away from the ship. Such an increase in rotation could only be caused by aerodynamics. However, there is no atmosphere in space, and as such aerodynamics do not exist there. As a result, Kane's body should rotate at a constant velocity after being shot out of the airlock.
- During the introductory external shots of the Nostromo, the stars in the background remain constant, even when the Nostromo and its cargo are shown from different angles, indicating the same backdrop was used.
- At the start of the film when the cockpit is shown for the first time, you can see the camera shake as it bumps into something whilst it pans towards the seats. The sound of the bump can be heard as well.
- When Dallas first interfaces with MU-TH-UR, he says, "Good morning, Mother." However, the voice does not sound like Tom Skerritt's.
- When the acid is burning through the Nostromo, the same shot of the blood burning through from above is used three times.
- When the crew are watching the acid eat through the decks of the ship, Parker says , "Take a look at this, man!" However, the movement of his lips does not match his words.
- Just before the dead Facehugger falls on Ripley, the collar of her outfit begins to pull downward, unnaturally, until the Facehugger drops onto her shoulder. There was likely some sort of filament, fed from below, through her clothing and attached to the Facehugger, that was used to pull the creature down onto her.
- When the crew are dining together just before the Chestburster scene, the scene cuts from a long shot, where Parker is saying something, to a closer shot, with the conversation continuing as before. Parker's voice can still be heard, but his lips are no longer moving.
- Following the Chestburster scene, as the camera pans around the darkened corridors just prior to Dallas ejecting Kane's body, what appears to be a boom mic is visible for approximately two seconds to the left of the screen.
- The wires holding up the Alien as it drops down behind Brett are visible.
- When Dallas is crawling through the air ducts before he is taken by the Alien, you can see dolly track for the camera along the floor.
- When Parker beats Ash with the fire extinguisher, the prop bends back and forth.
- After Lambert hits Ash with the electric prod, the camera pans down and we can see wires on the ground leading to the prop Ash torso atop Parker. The torso is also just a mannequin of a torso and has no legs connected to it.
- When Parker incinerates Ash, Ash's face melts off, revealing a solid dummy head beneath with no eyes and a sealed mouth.
- When trying to abort the self destruct, the cancellation instructions Ripley follows with her finger are actually just a French translation of the detonation instructions she followed earlier.
- After failing to shut down the self destruct, Ripley runs through a corridor filled with venting gas. As she steps out of the gas, the arm and head of a crew member is clearly visible near the large light. This is acknowledged on the DVD commentary.
- When Ripley is in the shuttle and has the space suit on, she hits the button to open the door and blow the Alien into space. In the shot just as the Alien is getting sucked backwards, the wire coming out of its back that pulls it is visible.
Aliens is notable in that some of the more famous/obvious goofs were later corrected for the Blu-ray release of its extended Special Edition. These corrections have been noted below, where applicable.
- Due to a different cat actor being used, Jones has noticeably changed his appearance since Alien.
- At the inquest, Ripley specifically tells the panel that Kane saw "thousands" of Eggs on board the Derelict. However, Kane never imparts this information to the rest of the crew when he enters the ship's hold in the first film; he simply says it is "full" of Eggs, without specifying how many that entails. Similarly, he could not have told the crew after waking aboard the Nostromo, because upon doing so he makes it clear he remembers nothing of the event.
- The signal that the Nostromo homed in on in Alien should have been heard by the vessels involved in the initial colonization of LV-426, or the ships supplying the colony, yet it remains undetected for 57 years. Director James Cameron has stated on several occasions that the equipment generating the signal had been damaged or destroyed by volcanic activity in the time between Alien and the colonization of the moon, but this is not mentioned in the film.
- In the extended Special Edition, Van Leuwen refers to Ripley's company ID number as NOC14472 while the data screen in the background displays the number NOC14672.
- Ripley lights her cigarette twice when Burke and Gorman come to see her in her apartment.
- Before the crew wakes up aboard the Sulaco, their names and ranks appear on a computer screen. The image quickly cross-fades to a shot of the crew asleep in their cryotubes, but if you look carefully just before the text vanishes, you can see that Hudson's name is missing from the manifest.
- During the wakeup scene, Apone calls for Crowe and Wierzbowski to get on their feet as he walks along the line of cryotubes. However, as he says it, Wierzbowski can already be seen standing at his locker in the foreground.
- The Colonial Marines can stand up straight inside the APC, yet are noticeably taller than it when standing outside.
- The mission time seen on the video feeds from the Marines' helmet cameras constantly jumps back and forth between shots.
- The motion detectors used in the film often fail to pick up the movement of nearby friendlies. It could be said that the Marines have some kind of technology that prevents the trackers from picking up their own personnel; however, at one point Apone asks his men over the radio if any of them could be the source of a movement signal, implying it is possible for the trackers to pick up other Marines. Similarly, Vasquez later suggests Hudson is detecting her.
- In the extended Special Edition, Ripley pauses hesitantly before entering the colony, standing in the rain for several seconds. However, as soon as she is inside, she is dry.
- The handle on the cup of hot chocolate switches sides when Newt drinks from it.
- When Apone is confiscating Pulse Rifle ammunition inside the Hive, he asks Wierzbowski for his magazine. However, all other shots in the film show Wierzbowski to be armed with a flamethrower, not a Pulse Rifle, and as such he should be exempt from the collection.
- Ripley's headset changes position when she is angrily confronting Gorman inside the APC.
- The APC window becomes unshattered after the vehicle rolls over the Xenomorph. The vehicle also has a large dent on its front right corner when leaving the Atmosphere Processor, but it disappears once the APC is outside.
- The acid blood of the Xenomorphs rarely seems to damage the walls and floors like it did in Alien. This is especially noticeable in enclosed spaces like the air shafts, the APC, and the elevator, where Hicks gets burnt but nothing else does.
- When Hicks is fleeing from the crashing dropship, his shoulder torch falls from his shoulder. The lamp then reappears later, without him ever picking it up and strapping it back on.
- Hicks warns Newt not to play with an M40 Pulse Rifle grenade when he's going through the weapons the survivors have left — it clearly has a pale green cap. However, the M40s used by Ripley in the Hive have red caps. The Colonial Marines Technical Manual makes it clear the cap on the M40 should be red, making the grenades Ripley uses correct.
- When sentry guns A and B start firing at the Xenomorphs in the tunnel in the Special Edition, one of the displays briefly shows that at least one of the guns has a full 500 rounds before opening fire. However, both guns fired several shots when Hudson and Vasquez tested them earlier, so they should have less than 500 rounds left.
- When Ripley tries to smash the unbreakable glass in the med lab, a scuff mark is visible on the glass before her first swing. After this, the mark disappears and we see Ripley actually making the mark with her second swing. This goof was fixed on the Blu-ray release of the Special Edition.
- Hicks gets sprayed with acid in the elevator. However, the burn marks on his face do not appear until later, when Ripley carries him out of the colony building.
- When Ripley is assembling her flamethrower/Pulse Rifle combination on the dropship, she first picks up a flamethrower from the rack. However, the next shot shows her setting down a Pulse Rifle. She then takes a Pulse Rifle from the rack, but the next shot shows her setting a flamethrower down on top of the Pulse Rifle. This is editing mismatch was later corrected on the Blu-ray Special Edition.
- When Ripley loads up her Pulse Rifle before going into the Hive, the ammo counter shows she loads it with a full magazine of 99 rounds. However, when she steps out of the elevator the ammo counter on the side of the rifle clearly reads 42, even though she hasn't fired a shot.
- The nozzle burner on Ripley's flamethrower goes out when she fires the weapon just before finding the discarded locator bracelet in the Hive. However, the burner is on again in the next shot.
- In the Hive, the ammo counter on Ripley's Pulse Rifle turns on and off between close-up shots of the ammo counter and full shots of her firing the weapon.
- The Pulse Rifle part of Ripley's flamethrower/Pulse Rifle combination changes many times in between shots. When she is firing the grenade launcher, the Pulse Rifle has eight barrel vents and a longer grenade launcher barrel, but when she is pumping the grenade launcher, the Pulse Rifle has a shorter grenade launcher barrel and eight barrel vents. When she is firing the Pulse Rifle itself, the Pulse Rifle again has a longer grenade launcher barrel, but this time has ten barrel vents.
- The elevator the Queen uses is not actually big enough for her to fit inside.
- When Ripley first grabs the Queen with the Power Loader, she grips around the creature's neck. However, in the next shot, the Power Loader's vice is holding the Queen's head.
- The yellow caution light on the Power Loader smashes when the Queen pulls the Loader into the airlock, but is unbroken in the next shot.
- The barb at the tip of the Queen's tail vanishes when she is in the airlock. It reappears when she is flushed into space.
- The position of the bandage on Hicks' head changes between shots as Ripley shuts him in his hypersleep chamber.
- During the investigation of the Atmosphere Processor, Lieutenant Gorman informs Ripley that the M41A Pulse Rifle fires "10 millimeter explosive-tip caseless" ammunition. However, several times during the film, the weapons can be seen ejecting brass casings, which a caseless weapon would not do. This is due to the Pulse Rifles being built around Thompson submachine guns, which fire .45 ACP rounds.
- In the Special Edition, when Vasquez and Hudson set up the sentry guns in the tunnel they test them by throwing a metal canister in front of them, causing the guns to fire at it and destroy it. Not only does this seem like a complete waste of ammunition, it is also tactically unsound as it alerts the Xenomorphs to their presence. In a combat scenario against a sentient enemy, it would also give away the locations of the guns, allowing the opposition to destroy or even circumvent them. It seems hard to believe such an advanced weapons system would not feature some means of testing its set-up without actually firing live rounds.
- The background conversation noise during the breakfast scene is obviously looped.
- Marks can be seen on the tabletop before Bishop starts the "knife trick", evidently from an earlier take.
- In the first wide angle shot of Bishop using the knife, he is stabbing it behind Hudson's hand. Furthermore, later shots have clearly been sped up, as can be seen from characters in the background, especially Sergeant Apone.
- Hicks deflects Drake's Smartgun upwards to stop him accidentally shooting Newt, yet the gunfire does no damage to the corridor's ceiling.
- A foot (presumably belonging to member of the crew) is visible over the edge of the catwalk when Frost falls to his death.
- The containers that supposedly knock Gorman out clearly do not hit him on the head, but on the arm and back. They are also obviously empty and too light to cause serious harm even if one of them had struck him on the head.
- After the dropship crashes, the paint on the handle of Hudson's Motion Tracker is obviously wearing off and the red of the drill used as the base for the prop can be seen.
- The barrels of the Pulse Rifles are clearly filled-in in some scenes, indicating that a dummy prop weapon is being used, rather than a real one. This is especially noticeable during the escape through the vents.
- When the Xenomorph snatches Newt, wires can be seen holding up its tail as it rises out of the water.
- While searching the Hive for Newt, Ripley fires bursts from her flamethrower to clear the way. Initially, this sets fire to the surrounding walls, as a genuine military flamethrower firing thickened liquid fuel would. However, this stops happening subsequently, indicating the weapon is suddenly a gas-fired prop flamethrower. When Ripley incinerates the Egg chamber, the blast from the flamethrower once again sets fire to everything it touches, as it should.
- The plastic hand of the Newt dummy being carried by Ripley in the Hive is very visible in some shots.
- When Ripley meets the Queen, there is a side shot where the breathing sound and the steam coming out of the Queen's mouth are out of sync. It is also possible to see that the steam is coming from the far side of the Queen's jaws, rather than out of them.
- As the Queen rears her head and roars when Ripley begins torching the Eggs, part of the metal structure inside the Queen puppet is visible.
- As Bishop is ripped in half by the Queen, her hands are clearly not gripping the two halves of his body.
- The hole through which Lance Henriksen's body disappears is visible when Bishop's severed torso stops Newt from being sucked out of the airlock. This was digitally corrected for the Blu-ray Special Edition.
- Between Aliens and this movie, the color of the Sulaco has changed from grey to brown, while the name on its hull is now written in white rather than black. The design of its hypersleep pods has also drastically changed, now appearing closer to those seen aboard the Nostromo in Alien.
- Arguably one of the most notorious continuity mistakes in movie history occurs right at the very beginning of the film — there is an Egg aboard the Sulaco, even though there is no conceivable way it could have got there. While it could be argued that the Queen brought it with her at the end of Aliens, a shot of her emerging from the elevator inside the Atmosphere Processor in that film clearly shows she is not carrying anything with either of her two pairs of arms before getting on the dropship, and without her Egg sac, it seems unlikely she could lay one whilst on board. More confusingly, the Egg in Alien3 seems to be in a completely obscure part of the Sulaco, when the only place the Queen could reasonably have deposited one (had she brought one aboard) is somewhere within the dropship's undercarriage, before she attacked Bishop.
- During the Sulaco evacuation sequence, a monitor shows an X-ray image of a Facehugger attached to someone (later events tell us this must be Ripley). However, a shot of Ripley being loaded into the EEV moments later shows she has nothing on her face.
- The previous films establish Facehuggers die as soon as they have implanted an embryo in their victim. However, the Facehugger in this film somehow impregnates two victims. The extended Assembly Cut explains this by making the Facehugger a previously unseen Super Facehugger, but the theatrical version makes it seem as though a normal Facehugger is suddenly capable of impregnating more than one victim.
- In the mess hall, the amount of orange juice in Ripley's glass changes between shots.
- When Clemens is discussing the prison's history with Ripley in the assembly hall, he points out that it has been "reduced to a custodial staff of 25", implying there are 25 people in total at the facility (not including Ripley, who has only just arrived). However, when Ripley meets with Andrews in his office later, the Superintendent tells her that he has "25 prisoners in this facility", implying there must be at least 28 people on the planet (25 prisoners plus three members of staff). By considering all of the names mentioned in the film's shooting script, it seems there are actually 22 prisoners on Fiorina, plus three members of staff, making Clemens correct. It is possible, of course, that Andrews was casually referring to himself, Aaron and Clemens as prisoners also, due to the fact they are effectively stuck running such a remote facility.
- In the theatrical version, the infant Dragon that comes out of Spike is bigger than the dog was to start with.
- A continuity goof exclusive to the Blu-ray release of the film's extended Assembly Cut — just before Murphy is killed in the ventilation shaft, he sees the Dragon moving around in a hole in the side of the shaft and, curious, leans in for a closer look. However, just as in theatrical version, he calls Spike's name, despite the fact the dog does not exist in the Assembly Cut. This mistake was not present in the Assembly Cut's earlier DVD releases, and is likely a result of the new sound mix created for the Blu-ray.
- When Aaron radios Clemens in his quarters and tells him about Murphy's death, he tells him it happened in vent shaft 22. Later, when addressing the prisoners about the event, Andrews says it happened in vent shaft 17.
- The Dragon appears red-brown in shots using a physical suit, yet effects shots showing the rod-puppet creature often give it a greenish tint.
- Prisoner Golic simply vanishes in the theatrical cut of the movie — he is last seen tied up in the infirmary during Clemens' death. The extended Assembly Cut features extra scenes with the character, revealing what happens to him, but his fate remains a mystery in the theatrical version of the film.
- At one point, Ripley mentions that Xenomorphs are afraid of fire. However, this was never really proven in the preceding films. In Alien, Ash proposes that the Alien may retreat from fire, but he is merely theorizing out loud when he says this. The only person to really use the flamethrower in the vicinity of the Alien in the film is Dallas, and far from fleeing, the creature quickly captures him. In Aliens, Ripley sets fire to the Hive at the end of the film, but is still attacked by Xenomorphs while doing so. In fact, all evidence points towards fire having no greater effect on Xenomorphs than bullets — it is an effective weapon when used directly, but has no greater intimidating impact on the creatures, and the mere threat of it is not enough to deter them.
- Dillon's glasses disappear during the conversation outside the nuclear waste tank after the plan to trap the Xenomorph fails (or after it is released from the tank in the extended Assembly Cut). He puts them back on later in the scene, but we never see him take them off.
- In the Assembly Cut, David identifies the first person killed during the bait and chase sequence as Vincent. However, in the scenes immediately prior to this, all of the surviving prisoners can be identified by name, and none of them are Vincent.
- Ripley is soaked in water when she douses the Dragon and causes it to explode, yet she is almost completely dry moments later when talking to Michael Weyland and his team. Even considering the high levels of heat inside the lead works, the change takes place far too quickly.
- When the EEV crashes into the ocean, a giant plume of water is thrown up. However, exterior shots of the planet show its surface is racked by ferocious winds, and as a result, the plume of water should have been blown immediately off to one side instead of rising neatly upwards.
- Ripley has a badly bloodshot eye following the EEV crash, yet it disappears quickly. Such an injury would actually takes days to clear up.
- At the end of the film, Ripley's signing off message from the end of Alien can be heard coming from the EEV, even though there is no reasonable way a recording of it could be stored on the pod. The novelization of the film explains that the message is not actually stored in the EEV at all, but is in fact lingering in the radio waves of space and is simply being picked up by the battered radio equipment on board the EEV. However, the film never explains this, making it seem as if the recording is coming from the EEV itself, which makes no sense.
- When Aaron attacks Weyland, he shouts out, "Fucking android!" However, the movement of his lips do not match his words.
- When the Chestburster is removed from Ripley 8, the incision is made below her breasts. Later, the scar is higher up, between her breasts.
- Ripley 8 has acid blood, apparently potent enough to burn through thick metal and toughened glass. Yet it does no damage to any of the surgical implements used to extract the Chestburster from her at the start of the film.
- During Dr. Gediman's discussion with Ripley 8 regarding her origins, he says she was cloned using "blood samples from Fiori 16, on ice". However, the planet's name (from Alien3) is actually Fiorina 161, nicknamed Fury.
- During the introduction to the crew of the Betty, when Call confronts Johner she places the wrench she is holding down on a surface. However, it falls off after she places it. Not only is there no sound of it hitting the floor, but it is suddenly back on top of the surface later on, without anyone picking it up.
- The money moves around on the table without anyone touching it during the meeting between Elgyn and General Perez.
- When Ripley 8 knocks Christie to the floor, we do not see or hear the barbell that he was holding fall to the ground.
- Immediately after the basketball fight, when Wren first appears, Vriess and his wheelchair disappear in the reverse angle.
- When Christie draws his Wrist Guns, his hands are behind his back, However, in the next shot they are hanging by his sides.
- The legs of the Cloned Xenomorphs differ between the practical suits and the CGI creatures, with the former having plantigrade legs while the latter have digitigrade legs.
- When the Xenomorph reaches up through the grating and Elgyn is shown getting pulled down, there is a big hole burned into the grate in front of him that was not there just a second before.
- When the survivors are cornered by a Xenomorph after Elgyn is killed, Distephano points out that they cannot shoot the creature because it is in front of the hull. Not only has gunfire been happening for half an hour or so before this (most notably heard off-screen during the initial break out) without anyone rupturing the Auriga's hull, Ripley 8 actually shoots the Xenomorph just moments later without causing any damage to the ship.
- Before the survivors discover the lab holding the failed clones, nine people walk past the camera. However, there are only eight survivors present at that point, as they have yet to find Purvis.
- The Chestburster inside Purvis does not emerge until the very end of the film, despite the fact every other colonist who was impregnated at the same time as him died many hours or even days earlier. Although the film's novelization states Purvis suffers from a low thyroid count, slowing the Chestburster's development, this information is never given in the film, leaving a glaring plot hole.
- The Newborn's mouth is dripping blood when it bites into Gediman's head, yet when it turns to Ripley 8 and roars in the next shot, the blood is gone.
- The blood spattered on Call's face when she is with the Newborn disappears.
- There is no blood on the Newborn's hand when it caresses Ripley 8's face, even though it crushed Distephano's head just moments earlier.
- The potential danger of gunfire rupturing the Auriga's hull is pointed out several times during the course of the movie. However, if this is such a threat, why are the soldiers stationed on board even issued rifles at all if they cannot safely fire them? Some other form of weaponry that would not endanger the ship would make far more sense, such as the electrical shock devices fitted to the assault rifles some of the men carry. What's more, even today, specialized ammunition types are available for use in just such a situation, where collateral damage from over-penetration poses a risk; for example, low-impact rounds are issued to air marshals aboard commercial flights so that they can use their weapons without rupturing the aircraft's fuselage. It seems unlikely future weapons would be incapable of using such technology.
- Wren claims there are twelve Xenomorphs remaining when asked how many more of the creatures exist. However, he could not possibly know this with any certainty at the time he says it.
- Shock and sound waves travel much further and faster underwater, and as a result, everyone should have been killed or seriously injured, or at the very least totally deafened, by the grenade that Johner uses to kill one of the Xenomorphs in the flooded mess hall.
- In all the previous movies, the victims of Chestbursters are completely incapacitated by pain during the birth, yet Purvis suddenly becomes seemingly superhuman when the Chestburster inside him begins to emerge; he gets shot almost a dozen times and yet still manages to walk across the room and give Wren a severe, prolonged beating. Even though it could be argued his body would be pumping with adrenaline, so many bullet wounds would have killed any human being, regardless of the amount of adrenaline coursing through their veins.
- Normal air pressure would be nowhere near sufficient to expel the Newborn through a hole as small as the one in the Betty's window, even in space. Moreover, the time it takes for the Newborn to be sucked out of the Betty's window would be more than enough to decompress the entire ship and kill everyone on board. Re-entering the Earth's atmosphere with the breach in the hull would incinerate Ripley and Call in the hold and likely destroy the ship.
- The barbell Christie hits Ripley 8 with clearly bends, revealing that it is made of rubber.
- In the first shot of Earth from space, the image has been flipped as Africa is facing in the wrong direction.
- When Gediman begins ranting in the Queen's chamber, the movement of his lips clearly does not match what he is saying. In fact, judging by the movement of his lips, he is literally saying, "Blah, blah, blah..."
- Weyland-Yutani Archives - Ripley's Nosebleed
- Strange Shapes - Debate: Loving Lambert
- Weyland-Yutani Archives - James Cameron's Responses To Aliens Critics
- Weyland-Yutani Archives - Whose Who in Alien 3
- Alan Dean Foster (1992). Alien3 novelization. Warner Books, Inc., 185.
- Ann Crispin (1997). Alien Resurrection novelization. Warner Books, Inc., 91.