Ridley Scott introduced Ellen Ripley in Alien in 1979, and the most important thing she does in the entire film is try to enforce quarantine. Kane has a creature attached to his face. Dallas wants to bring him aboard. Ripley, as warrant officer, cites protocol: nobody with an unknown organism comes back on the ship until it has been studied. She is overruled. Ash opens the door. Every death that follows is a direct consequence of someone ignoring the one person who was following the rules.

Ripley survives Alien not because she is the strongest, the fastest, or the most heroic. She survives because she is competent, procedurally correct, and unwilling to let sentiment override safety. These are not traditionally cinematic qualities. They are the qualities of a good employee, and Scott's genius was recognizing that a good employee, in a horror scenario, is the person most likely to live. Dr. Barbara Creed of Monash University, in her theory of the monstrous feminine in horror film, has analyzed Ripley as a character who survives by maintaining boundaries that others, particularly male characters, are willing to compromise.

The Cat and the Flamethrower

Ripley goes back for the cat. She has set the Nostromo to self-destruct, she is the last human alive, and she turns around for Jones the cat. This detail is what separates Ripley from a survival algorithm. She is practical and she is sentimental, and the sentimentality does not compromise her effectiveness. She gets the cat and she escapes. Both priorities are met because Ripley is organized enough to accommodate compassion within an emergency plan.

Get Away From Her

Aliens, the sequel, transforms Ripley from survivor to warrior, but the transformation is motivated by maternal instinct rather than revenge. Ripley fights the Alien Queen not to save humanity but to save Newt, a single child who has survived alone in a colony of death. The line, get away from her, delivered while strapped into a power loader, is the most iconic moment in action cinema, and it works because it is not a battle cry. It is a mother's warning.