[[folder: Fridge Brilliance ]]

* A lot of people wondered why the Predalien looked so radically different from the human-born aliens, whereas the dog alien from the third movie looked pretty much the same aside from some cosmetic differences. This makes sense when you consider that the DNA difference between a human and a dog would be much smaller than between a human and a life form from a completely different world.
* The events of ''[[Film/{{Prometheus}} Prometheus]]'' provide a plausible explanation for why Mother was able to decode some of the distress signal in ''Alien''.
* A lot of the [[ArtisticLicenseBiology things that don't make sense]] about the Xenomorph make a lot of sense if you consider the possibility that they were designed as [[LivingWeapon weapons]]- HollywoodAcid for blood: defense mechanism as well as the 'living battery' idea proposed in the comics. Ability to reproduce with almost any species: A perfect way of making more of them that demoralizes the enemy in the process, as well as incorporating the abilities of other species in the Xenomorph's 'design'. Taking on the characteristics of the animal they hatch from is even more sensible: that creature was already adapted to its environment, so the Xenomorph is adapted to it, as well, and adding its own advantages. And odds are the Xenomorph is taking as hosts the dominant lifeform in a given ecosystem (i.e., humans for most of the franchise), making it that much more capable.
* Might seem horrific, but a lot of Weyland-Yutani's actions are a lot more understandable if you look at it the right way. They want the aliens as bio-weapons. Seems like a fairly typical power-hunger thing that any bunch of {{General Ripper}}s would do, right? Until you think about who they might need to use them on. The galaxy has just been proven to contain other intelligent, spacefaring lifeforms, or at least it did, ones vastly superior to humanity. And they're probably still around. Even if they're not, other species probably are -- indeed, given the implied shared verse, the [[Franchise/{{Predator}} Yautja]] are certainly still around. Controlling the aliens provides Earth with a guaranteed-effective weapon against any aggressors. In essence, they're looking for a trump card to insure the survival of the human race. In that context, they might still be crazy, but they're more KnightTemplar types than the omnicidal maniacs that they look like otherwise.
* ''Videogame/AliensColonialMarines'' may seem like it's {{Retcon}}ing things when it explains that a Chestburster gestates inside a parasitic "mock-womb" that will kill the host even if the xenomorph embryo is removed, but this actually explains something: in every continuity, we almost never see facehugged victims ever be surgically cured; surely, sheer practicality would dictate that even for a {{Megacorp}} it's more profitable to surgically extract a grown Chestburster from a victim than allow it to deliver itself in the usual lethal manner, but nobody ever does so. Even the rare benevolent "xeno-farmers" use surgical clone-lumps (non-sentient masses of clone-grown human tissue and organs) and let the Chestburster grow and remove itself from them.
** At the same time, Ripley 8 having her Chestburster surgically removed makes sense; Film/AlienResurrection is set several centuries into the future of the timeline of the rest of the Alien franchise.

[[folder: Fridge Logic ]]

* How could the Xenomorphs make effective biological weapons? Their only method of killing relies on getting close to their enemies, which makes them easy to kill at a distance. Since they cluster in hives, it should also be relatively easy to bomb them from the safety of the air. Even if you were to disperse a bunch of facehuggers in a densely populated area, it would become impractical once the enemy knows what they're up against and would learn to kill anyone who's been infected after the first use. You could use something that's not a Xenomorph and that something else would likely be able to do it better.
** If you're fighting a stand-up war, sure. But Xenomorphs clearly aren't a weapon of war, they're a weapon of terror. They're designed to be as frighteningly efficient at killing as possible, and even if you can defend yourself against them, their acid blood will do a good job at damaging or destroying nearby infrastructure. They may make an easy target clustered in hives, but first you have to find the hive, and Xenomorphs are sneaky above all else. Adding all this up means that, while Xenomorphs might not win you a war, they'll certainly distract and disrupt your enemy, giving you the advantage.
* If you have quarantine procedures, and a medbay, why would those procedures not include "isolate in (specific part of) medbay, send in the android science officer to examine/operate, sterilize android after"?