If you're looking for a way to add tension to your romance novel, there are a slew of tropes out there to try. Enemies-to-lovers is usually the go-to, but for a twist, try the class differences trope.
It's a common trope in historical romance. It makes sense when you think about it—it's harder to distinguish between classes in the modern West, but in centuries past, the task was much easier.
From someone's clothes to their accent to their profession—or lack thereof— there were many visible and/or audible clues that hinted at someone's class.
The class differences trope also lends itself well to historical romance because one of the best examples of it is from the Regency era.
It's—you guessed it—Pride and Prejudice.
Class differences are the basis for some, though not all, of the external conflicts that Lizzie and Darcy have to battle on their way to love. And though the book ends in a happily ever after, it's clear that they'll never totally escape the repercussions of their origins.
Authors have applied the class differences trope to other historical eras, including:
The 1920s, with Slippery Creatures by KJ Charles
The Gilded Age, with Baron by Joanna Shupe
Edwardian, with The Nature of a Lady by Roseanne M. White
But the class differences trope isn't just for historical romance. It's prevalent in contemporary romance, too, though usually with different character archetypes. Instead of dukes and earls, you have royals. Instead of wealthy industrialists, you have billionaires, business heirs, rockstars, and actors.
But the conflict the trope creates remains the same: two people, from two vastly different backgrounds, trying to figure out how and if they can make it work with someone whose lifestyle seems totally different from theirs.
My favorite contemporary examples of the trope are:
A Duke by Default by Alyssa Cole (royal!)
The Stand-In by Lily Chu (actor!)
Hurts to Love You by Alisha Rai (heiress!)
Read these for inspiration and see how you can apply the class differences trope to your next romance novel.