We talk a lot about the importance of writing characters that readers like or can relate to—and by "we" I mean anyone who feels strongly about books, regardless of profession. It's nice to know when the good guy is good and when the bad guy is bad. That's what you expect from a story. You want a hero, right?
Nope. Not this reader.
I love unlikable characters. It's fair to say that if there's a no-good, dirty, rotten scoundrel in the lead, I am 100 percent on board. But it seems incongruous, doesn't it, that a character who is wholly unappealing—repulsive, even—should be something readers might seek out. And one step further, it seems counterintuitive to recommend that you write characters that readers will rightfully dislike. And here, I think, is where unlikable and uninteresting are confused.
Be they bad apples or good eggs, a character needs to exhibit enough agency to earn a reader's attention—regardless of whether that attention is positive or negative. And herein lies the key: You can make your protagonist as low-down and dirty or as mindful and generous as you please, but she has to be the engineer of her own conflict to earn readers' interest. A character—good or bad—must be an active participant in her own story. And if you want a character with a built-in conflict machine, you should go low-down and dirty.
Some characters are difficult to connect to simply because they do little to engage a reader. A character who lets the world act upon her and doesn't influence a change in her situation could be unlikable or lovable, but either way, she's uninteresting. She’s too passive to warrant concern. You can't care about this character, and as a result, you can't care about her story. You'll lay the book aside and tell your reader-friends that the character is unlikable. But a more accurate sentiment might be that the character isn't interesting or compelling—all things that even a good-girl character needs to be if she wants readers to care about her enough to finish the story.
But the opposite—a character who sets himself up for conflict and consequences through the dastardliness of his doing—is surely unlikable, yes, but also magnetic. You want to watch him ruin his life. He repulses you in the same way a car accident is simultaneously disturbing and hard to look away from. This character is a train wreck, and it is glorious to behold. Every time he does something unwholesome, immoral, felonious, or just, like, super-rude, he creates a conflict. The anticipation and delivery of that consequence are deeply satisfying for a reader, and by their very nature, not-nice characters create these conflicts almost constantly. In the words of Oscar Wilde, “The suspense is terrible; I hope it will last.”
Think about this: You have an idea for a novel. You've been working on it for quite a while now, but something isn't clicking. Your protagonist is a woman who's down on her luck. She is now in a bind and needs some help. She's lost everything: her boyfriend, her house, her job. Even her cat disappeared. Man, what a mess.
In Scenario A, your protagonist asks her parents for money, but they can't give her that. So Instead, they let her stay in their home until she can get back on her feet. Maybe she doesn't love living with her mother. Maybe she never finds a job. Maybe she's camping out in the basement for so long that her parents leave and tell her to keep the house. Win-win, and your character is still a nice girl. That was easy, right? Yep, and honestly, pretty boring.
In Scenario B, no one can (or will) help her out. Your protagonist is living in her car and yet no one is there to lend a hand. Why not?, you're asking. Good question. If she's a good person and her circumstances truly are outside of her control, then surely someone can give this nice lady a hand. But let's pretend she's not a nice lady. Maybe she kicks puppies on her lunch break. Cheats on her taxes. Kidnaps kids for ransom. Kills her boss in a fit of rage and frames her coworker (the nice guy, of course). What if we find out, for example, that her house and boyfriend and even her cat are gone because she's a manipulative sociopath who tied the guy to the bed and then burned the place down so he couldn't leave her? That is much more interesting than a girl who needs to sofa-surf at Mom's until that next job interview.
The character from Scenario A may well be the sweetest, kindest woman who ever existed in print. In fact, I'd put money on it. Poor girl just had a bad week. But the protagonist from Scenario B is going to be infamous, and even if we hate her (and we will, that murderous wretch), we'll still think about her after the book is back on the shelf. (Both scenarios were made up on the fly as I typed this; if they resemble actual works of fiction, my apologies. If not, those ideas are free to use.)
Let's look at some fictional characters who are generally considered unlikable.
Rabbit Angstrom, the protagonist of John Updike's Rabbit, Run and its sequels, is a (slightly) less sadistic character who manages to ruin the lives of every woman he meets. And as often as he isn't doing the hard work of being gainfully employed or staying faithful to his wife, Rabbit is no slouch when it comes to creating an avalanche of consequences for himself. He's an aimless, unkind, jealous cheat, and watching him scramble to avoid the falling walls of his life is as entertaining as a story gets.
Lolita's Humbert Humbert is a monster by every definition, a "detestable, abominable, criminal fraud" according to his wife (and Dolores' mother), and a "vain and cruel wretch" in Nabokov's own words. The reader understands that he's both human and inhumane, and because he chooses to give in to his baser instincts, he earns both the consequences of such and the dislike of readers.
Frank and April Wheeler, the lead characters in Richard Yates' Revolutionary Road are unbearable, conniving snobs. Their shortcomings and pettiness and self-righteousness and backstabbing create every major plot point in the story. Yates' debut novel remains among my favorites because I'd never want to know them, but it's not very difficult to imagine the Wheelers living next door, driving each other insane.
Gillian Flynn's Gone Girl features two of the most despicable characters to ever grace the page. I stayed awake reading through the night to find out who I was supposed to be rooting for, and in the end, I hated Nick and Amy Dunne equally and fully and I loved every word of it. Unlikable? Absolutely. Uninteresting? Not for a second. The novel could accurately be retitled Two Cats, One Bag.
The compelling unlikable character exists in every medium. Books, film, TV, plays, you name it. Add Joffrey Lannister (Game of Thrones), Javert (Les Miserables), Yvonne "Vee" Parker (Orange Is the New Black), Alonso Harris (Denzel Washington's character in Training Day), Ignatius J. Reilly (A Confederacy of Dunces), the Narrator in Fight Club (or more broadly, possibly every character in every Palahniuk novel), Holden Caulfield, Jack Torrance ... there's no end to this list.
But in every case, the unlikable character who earns our attention is generating problems that require resolution—problems that carry the plot forward in a logical, organic way. The unlikeable character is a one-man plot-building machine, and I wholeheartedly encourage you all to try it at least once.