In Bladerunner, Harrison Ford plays the bladerunner, Deckard, who is hired to kill the A-Wall machines that have intruded Earth. Deckard then goes and hunts the machines down. There is much speculation that Deckard is in fact a replicant. However, I believe that he is not a replicant but a human. .
When Deckard ordered Chinese food and the policeman came and spoke to him using the gutter talk, he later says in the narration that he understand this complex language, but he acts like he doesn't know it to avoid a confrontation that might result in bodily harm. I believe this is an instinct of humans because humans will try to resolve problems without means of violence. Later, the bladerunner meets Pris, the stripper girl, and he tries to take advantage of her. Deckard has a sexual attraction for her and wants to take advantage of her in order to fulfill his sexual desire. A sexual desire is purely an emotional trait of living beings, not machines. I noticed that Pris never tried to stop him when he was forceful in kissing her. She just stood there blank faced while Deckard had a slight grin because she couldn't comprehend what he was doing to her. Human kissing involves emotion. Another reason why I think that Deckard isn't a machine is at the end of the movie when he is hanging off of the roof of the building with the leader looking at him, he is slipping. He isn't able to hold onto the edge of the building to save his own life. As mentioned earlier in the movie and on the profiles, replicants are considerably stronger than humans. I believe if Deckard was a machine that he would be able to hold onto the edge of the building and climb up, and not have his grip slip causing him to have fallen to his death. Also, since machines are just as strong as each other, the leader should not have been able to take away Deckard's gun when he is trying to shoot him in their confrontation with each other.