Ellen Ripley (Sigourney Weaver) in ALIEN is a supporting character for the film's first half. It was a wise choice to do.

She doesn't even get top billing, Tom Skerrit does. In the first hour of the movie, the focus appears to be on Skerrit, Veronica Cartwright and John Hurt. Sigourney Weaver is a mostly background character, someone you wouldn't expect to be the last survivor and protagonist.They also pulled a Psycho with Skerrit's character, even bolder than Janet Leigh's, since Leigh didn't even get top billing in PSYCHO. Skerrit did in ALIEN.By the 2nd half, the mood changes when Weaver takes over and we get to see more of her. Weaver's performance is superb, it's a far cry from her action type part in ALIENS. In ALIEN, she's just struggling to survive. via /r/movies https://ift.tt/dtNLRhi