At some point during the making of Blade Runner, Ridley Scott decided that it would be brilliant if Harrison Ford’s character were a replicant.
Some kind of irony, I suppose, that Deckard was retiring replicants but was a replicant himself without even knowing it.
So he added the unicorn scene in the Director’s Cut so that we could all be let in on the joke.
And then Hampton Fancher, Michael Green, Denis Villeneuve, Harrison Ford and Scott himself became involved in making a sequel. So they had to face this question. Obviously Ford was going to look a lot older in the sequel. So what would that mean?
So the decision they made was to leave the question just as open as it was at the end of the first movie.
But for me (as for Harrison Ford) Deckard was always human. And the unicorn scene was a mistake.
The reason I think Deckard was human was because he was clearly no match for the replicants in combat. He was lucky to survive each encounter with a replicant. He only survived the final encounter with Batty because the latter allowed him to. And he felt pain, as the fight with Batty so clearly illustrated.
And the reason I thought that Deckard should have been human was that he represents us. In his encounters with Rachel. In his encounters with Batty. The movie only makes sense if he is a human experiencing those emotions. Feeling empathy for Batty. Falling in love with Rachel. And Batty chooses to let him live. Not because Deckard is another replicant. But because Deckard is human. When he says “I’ve seen this you people wouldn’t believe” he is referring to “you humans”, in my opinion.
So Ford is right, and Scott is wrong.
And Fancher and Villeneuve (presumably out of respect for Scott) decided not to set the record straight.
Here is the great “Tears in Rain” scene from the original movie.