Deadly Friend: An Autopsy, article by Joseph Maddrey from 2014 that he did for Deadly Magazine went into great details about entire back story and production problems of the movie, and different versions of the script;
Bruce Joel Rubin submitted his initial story treatment - titled "A.I" - to Warner Brothers in May 1985, followed by a first draft screenplay on July 19. His idea was to get away from Frankenstein clichés of the book, and both Craven and producer Robert Sherman liked that. According to Rubin, Craven really wanted to "make something that had more basis in character and sort of emotional underpinnings that he had not had in his other films."
In subsequent drafts of the script, there was greater focus on developing Sam and BB as complex characters. One scene that didn't make it into the final film was a poignant dialogue scene between Paul and Sam in which they discuss their absent parents. Paul has come to terms with his father's absence, but Sam continues to express hatred and rage toward the mother who abandoned her and the father who abuses her. Paul responds like a mature advisor, diagnosing her repressed anger as battered child syndrome. It's obvious that Sam is already predisposed to become a monster.
In Rubin's earlier screenplay, there was also a dream scene where Paul dreams Sam standing by his bedside covered with blood. Then after he wakes up he finds out that she killed Elvira. Craven however didn't liked this version of the scene so for the final version in the movie he changed it so that Paul dreams Sam's burned father Harry breaking out of his bed and laughing at him, only intended by Craven to be a sly nod to his previous film, A Nightmare on Elm Street.
Character Carl, the bullying biker, was added in early draft of the script by Rubin to appease Warner Bros. president Mark Canton who requested that they need to "toughen up" the first act.
In the final shooting script, submitted in December 1985, in the scene where Sam finds photo of herself with Paul and BB and when she sheds a tear (this part of the scene is still in the movie), Paul embraces her.
In an effort to highlight the love story, Rubin has avoided the more overly horrific details of the novel, including a gruesome sequence where Paul sees that rats have been gnawing on his dead girlfriend's toes, as well as subsequent bathtub sequence that could have been perversely erotic.
Rubin remembered that this script, which had more of a sweet and fantastic tone rather than twisted and gothic, was read by then Vice President of Warner Brothers Lucy Fisher and that she called him one morning to tell him that the script made her cry. He reflected; "I had to ask her which script because i couldn't believe it was Deadly Friend. She was really moved by the story. So at one point, it really had a bit of a heart and an emotional life that was compelling." Even in on-set interview with Starlog journalist Lee Goldberg, Rubin claimed; "Deadly Friend is an unexpectedly tender movie. It's really story about romantic obsession and the length to which someone might go to be with person he loves."
Death scenes of Harry and Elvira were completely different in shooting script. In Harry's death scene, Sam comes at him with her arms stretched out like Frankenstein's Monster but his death is left for viewer's imagination, although Paul later finds his dead body stuffed in furnace. In original version of Elvira's death, Sam shoves the old woman's head through a door. As its well known, few shots of this original death scene are shown in theatrical trailer. In previous drafts of the script, Elvira is electrocuted by Sam.
Ending of the movie was completely changed. In the script, final act and confrontation with Sam starts in Paul's living room, and not with her jumping out of the window and attacking Tom. Couple stills showing Paul and his mom with re-animated Sam in their living room prove that this ending was indeed filmed. In the shooting script, it's also made clear that in her last moments, before she is shot and killed, she runs towards the cops and Paul because she is trying to protect him.
Ever since production began, everybody involved knew that Sam/BB couldn't really be dead at the end of the film. Rubin initially proposed an ending in which Sam escapes from the morgue only to be picked up by a hitchhiker who screams when he gets a good look at her. In a subsequent draft, she appears in Paul's bedroom at night. A dreamy image of undead Sam wearing a white dress on the back cover of Twisted Terror DVD release suggests that this scene was actually shot.
When he was asked about original version of the film (before test screenings, re-shoots and re-edits) Rubin fondly remembered that this version "did have a kind of emotional underpinning that got decimated by the next cut." Amongst many other scenes, this version of the movie also included few additional character based scenes that appear in shooting script. Some examples include the tender scene where Paul and Sam talk about their missing parents, a scene where Paul waits by Sam's hospital bedside, a scene where Paul's mom tries to console him after Sam's death, a montage showing undead Sam's feeble attempts to learn how to walk and talk, and a scene near the end of the film in which Paul tells Sam that they need to run away together. Official publicity and promotional stills, US and international lobby cards and many other pictures show lot of these and other deleted scenes confirming that they were filmed.
Some of the scenes from earlier drafts of the script are also possible to be filmed but deleted; A poignant funeral for BB that strengthens the bond between Paul and Sam, a pivotal moment when Paul heatedly lashes out at Harry Pringle after learning of Sam's death, an extended conversation between Paul and his mentor Dr. Johanson that addresses the moral implications of Paul's experiment, and a later scene in which Paul expresses guilt and remorse over what he has done, only to realize that his love for Samantha outweighs everything else. See more
Old man Pringle and Mrs. Parker, both dead. His face was burned off.
Yeah, I heard somebody say she called the police. Said she saw Sam in her bedroom window. From what I hear, Elvira's head's all over the walls in there.