As a result of Fancher’s divergence from the novel, numerous re-writes before and throughout shooting the film, and the fact that Ridley Scott never entirely read the novel on which the film was based, the film diverged significantly from its original inspiration. Some of the themes in the novel that were minimized or entirely removed include: fertility/sterility of the population, religion, mass media, Deckard’s uncertainty that he is human, and real versus synthetic pets and emotions.
Upon entering Sebastian’s apartment, Deckard is ambushed by Pris, but manages to kill her just as Roy returns. As Roy’s body begins to shut down, he chases Deckard through the building and ends up on the roof. Deckard tries to jump to another roof, but misses and is left hanging precariously between the buildings. Roy makes the jump with ease, and as Deckard’s grip loosens, Roy hoists him onto the roof, saving him. As his life runs out, Roy delivers a monologue about how his memories are about to be lost; Roy dies in front of Deckard, who watches silently. Gaff arrives and shouts to Deckard, “It’s too bad she won’t live, but then again, who does?” Deckard returns to his apartment to find Rachael sleeping in his bed. As they leave, Deckard finds a small tin-foil origami unicorn, a calling card left by Gaff. Depending on the version, Deckard and Rachael either leave the apartment block to an uncertain future, or drive through an idyllic pastoral landscape.