Tools of Characterization
Characterization in Blade Runner
Actions
Actions speak louder than words—and killing people speaks louder than most actions. We witness lots of killing in this movie: we see Deckard killing Zhora, we see Rachael killing Leon, we see Roy killing Tyrell.
When Deckard kills Zhora, it shows that he's determined to do his job—but he's not thrilled by it. It's hard and highly dubious morally. It's not "fun" for him. When Rachael kills Leon, it shows that she's just as attracted to Deckard as he is to her—and that she's likely in love with him. And when Roy kills Tyrell, it shows that he's willing to murder his own creator as a protest against the slavery he's suffered and the limited lifespan he's been given.
But we also see Roy forgiving Deckard, and that might be the action (or lack of action) that speaks loudest of all. It shows that Roy isn't just some machine—he has empathy and grace or, in other words, a soul.
Clothing
The clothing in this movie is appropriately dark and edgy. Pris's punk fashion choices—torn nylons and fishnets—highlight her personality as a fighter, while Rachael's black and grey suits and fur coats signal that she's the detective's classic love interest, as in most film noir. Deckard's trench coats give him a pre-Matrix feel, whereas Gaff's bowtie and fedora make him seem oddly quirky.
And did you notice that the clothes are uniformly reflective of classic '40s noir fashion, even though the film was set in the future?
Location
This evil futuristic version of L.A. colors all of the characters' personalities. Take J. F. Sebastian's creepy apartment: he's surrounded by weird, interactive toy-beings, indicating that he doesn't have real human relationships, only relationships with things he's produced. Deckard's apartment has a cold techno-feel to it, while Tyrell lives at the top of a ziggurat—giving us a hint that he has the personality of a tyrant.
Real human interaction is at a minimum in this location, even thought it's full of people. It's no wonder that everyone seems terribly lonely.
Occupation
If you're a blade runner, your job is to blow people's brains out—if replicants can be considered "people," that is. So it's a dubious job: it's dirty work, and it's probably immoral to boot. You get a sense that Rick Deckard and Gaff aren't sweet, rosy-cheeked little cherubs, but at the same time, neither of them seems particularly evil. It's a complicated world they live in.
Deckard is deeply conflicted about his job, which seems to be part of the reason he drinks alone—also, falling in love with a replicant doesn't make anything easier.
As for other professions: J. F. Sebastian is a genetic designer, as are Hannibal Chew and Dr. Tyrell. This makes Sebastian, at least, a fairly odd figure, one who creates his own "friends" and keeps away from connections with other people. He lives in a world entirely conditioned by technology.
We might also consider the replicants themselves, who were slaves in the "off-world" colonies: Roy was a soldier slave, and Pris was a "basic pleasure model" (ahem, a sex slave). This spurs their intense desire for freedom as well as their quest for more life. Roy captures the essence of his old occupation, saying to Deckard, "Quite an experience to live in fear, isn't it? That's what it is to be a slave."
Physical Appearances
The characters' physical appearances help contribute to the movie's general vibe: for example, Pris wears creepy makeup when she fights Deckard, blending a punk look with a scary clown look. Roy's bleached blonde hair and chiseled features make him look like a bad boy you don't want to mess with, and J. F. Sebastian's simultaneously old and young face hints at the fact that he suffers from a disease that is prematurely aging him.
As for Deckard himself, he has the look of a classic film noir detective—mixed with a close-cropped, slightly punk haircut. This speaks a great deal about the character, since he's superficially a tough guy, but—in traditional film-noir detective style—he has secret doubts and pains and insecurities.
Props
The fake family photos owned by Rachael are some of the most significant props in the movie. They give her a point of orientation in the world, a sense of identity. Leon collects photos, too. Nowadays people post pictures of themselves on Instagram in order to remind themselves that they exist, and the replicants do pretty much the same sort of thing. They need these photos, because they help ground them in a sense of reality. Without them, they'd be identity-less and adrift. As Deckard puts it in his voiceover: "Leon's pictures had to be as phony as Rachael's. I didn't know why a replicant would collect photos. Maybe they were like Rachael. They needed memories."
Sometimes the props are overtly symbolic. The nail Roy drives through his hand is a crucifixion symbol, which makes Roy into a slave who suffers for the sins of humanity, and the dove he releases at the end symbolizes both his soul and his basic innocence. Gaff's origami creatures hint at a weird sense of humor. For example, he sits a chicken in front of Deckard when Deckard's thinking of refusing the mission. He also creates a matchstick man with an erection, which he leaves behind at Leon's house, and he indicates that he knows Deckard's dreams when he leaves an origami unicorn at Deckard's apartment towards the very end of the movie.
Sex and Love
When Roy unites with Pris at Sebastian's apartment and makes out with her, it reveals an important point: replicants can love. Deckard and Rachael have a relationship, too: Rachael cares enough about Deckard to blow Leon's brains out and save him, and they sleep together shortly thereafter. At the end of the movie, they're able to actually say "I love you" to each other.
On the one hand, we can see their relationship as being different from that of Roy and Pris. Deckard is ostensibly a human, while Rachael is a replicant but by recognizing humanity in Rachael, Deckard comes to see the replicants as more than just technology.
Social Status
The replicants have next to no social status in this movie's world. They're supposed to be slaves on distant colonies in space, and they aren't even allowed to be alive on earth. You can't really get much lower down the food chain than that. This low status is part of what makes the replicants fighters: their whole role in the movie is to struggle for survival, even if it requires murder. By contrast, their creator, Dr. Eldon Tyrell, runs the corporation that seems to dominate much of the world.
As for the main character, Deckard, he doesn't have much status, either. When he tries to refuse his assignment to hunt down the replicants, his boss Bryant yells at him: "Stop right where you are! You know the score, pal! You're not a cop, you're 'little people.'" A blade runner isn't really on the same level as the police, and maybe that's because of the dirty nature of their work. Thus, Deckard isn't happy with where he is in the system: his freedom is limited, and he's forced to do brutal work that seems fairly unethical.
Speech and Dialogue
There are lots of different modes of speech in Blade Runner. Deckard speaks like a hardboiled detective, Gaff speaks in multilingual street slang, and Roy speaks with a poetic eloquence you might not expect from someone who was created specifically to fight in outer-space battles.
When he walks into Hannibal Chew's lab, he quotes William Blake's America: A Prophecy, comparing himself to a fallen angel: "Fiery the angels fell; deep thunder rolled around their shores; burning with the fires of Orc." This gives him a mythical quality that many of the other characters don't have, even though he's a replicant and isn't supposed to be considered a full human in his society. The dude is larger than life.