10 Horror Movies You Didn't Realise Stupidly Broke Their Own Rules
9. The Acidity Of Xenomorph Blood - Aliens
The Rule
Ridley Scott's original Alien makes it unforgettably clear that the Facehugger's highly acidic blood is capable of eating its way through two floors of the Nostromo in just a matter of seconds.
The Breaker
But from James Cameron's superb sequel Aliens onwards, the acidity of the Xenomorph blood is largely dialled back.
We see Hicks (Michael Biehn) able to free himself from his armour before the blood melts through it, Vasquez's (Jenette Goldstein) leg somehow isn't melted down to the bone when it comes into contact with the blood, and Hudson's (Bill Paxton) arm is in surprisingly decent condition after being burned by it.
This inconsistency only grew in the subsequent sequels, such that it's basically a fool's errand trying to make crystalline sense of how strong Xenomorph blood is truly meant to be.