The question of whether or not memories and emotions make a human a human is central in Bladerunner. The main character, Deckard, is tasked with destroying four replicants, which are basically robots that have implanted memories and a short lifespan. Some replicants escaped their home/work turf and traveled to futuristic Los Angeles to try to permanently extend their lifespan. Deckard first goes to Tyrell of the Tyrell Corporation, who has the most knowledge of the kind of replicant Deckard is hunting. While there, he meets Rachel, a replicant who believes she is a human. She and Deckard become acquaintances, and she tries to tell him that she really is human based off memories of specific photographs of what she thinks is a childhood. Deckard offers up a quick explanation, but is nevertheless intrigued. Meanwhile, two of the replicants, Roy and Pris, end up in the home of a man who is friends with Tyrell. Roy convinces him to take him to Tyrell, who he eventually kills when he is denied a lifespan extension. Deckard tracks them to the house, and them promptly kills Pris before Roy returns home. They fight and run up to the rooftop, and when Deckard is dangling from the edge of the roof, Roy saves him before his life runs out. The final scene is of Deckard leaving his house with Rachel and, after seeing an origami unicorn on the ground, experiences a flashback of a dream. It is implied that there is a possibility that Deckard is actually a replicant.
Bladerunner is like a old western movie set in a futuristic setting. The sheriff, Deckard, is out hunting some lawbreaking bandits, the replicants. However, instead of having clear cut good vs evil themes, Bladerunner is more ambiguous. The movie is about memories, and what role they play in making some human. Rachel is definitely a replicant, as she said so herself, but she looks, talks, acts, and thinks like a normal person. She tells stories of her past life, and whether or not that actually happened, anyone but Deckard and Tyrell would likely believe that she is a human. Because of this, most people would probably think that, for all intents and purposes, she is human. The film definitely emphasized the more emotional aspects of robot/human debate, contrary to Total Recall which was all action and dead people. The intent of Bladerunner seemed to be to make the audience question the definition of humanity, and what are the most important characteristics of people. Clearly, the movie says that memories and personality are more human than looks or strength, and it makes a convincing argument.