 All of the names of the main characters were changed by  Walter Hill (I) (qv) and David Giler (qv) during the revision of  the original script by Dan OBannon (qv) and  Ronald Shusett (qv). The script by OBannon and Shusett also had a  clause indicating that all of the characters are "unisex", meaning  they could be cast with male or female actors. However, Shusett and  OBannon never thought of casting Ripley as a female character.