Every genre has its recurring shapes. Mystery has the locked room. Thriller has the unreliable narrator. Romance has its set of tropes, enemies to lovers, only one bed, found family, marriage of convenience, second chance, and the readers who buy these books actively seek them out by name. A new release will frequently list its tropes in the marketing copy. The reader picks based on the list.
It is easy, from outside the genre, to read this as formulaic. Inside the genre, it reads as honest. The reader is telling the writer what shape of book they want to spend the next four evenings in. The writer is agreeing to deliver that shape. The interesting question is what the writer does inside it.
Enemies to lovers
The most dominant trope in the genre, by sales. What it offers, underneath the rivalry, is a structure for showing a character through two completely different lenses: the one their adversary sees, and the one their partner sees. A well-executed enemies-to-lovers book is, secretly, a study in perception. The trope is a frame for the same character to be misread and then read correctly.
Only one bed
A trope so famous it has become a punchline, and yet it still works. The mechanism is simple. Two characters who have not yet admitted what they feel are placed in physical proximity they cannot escape. The proximity does the work the dialogue cannot. It is a forced-attention device, and it survives because forced attention is, dramatically, very honest.
Found family
The fastest-growing trope of the last five years, and not by accident. It is the trope that maps most directly onto the actual social experience of younger readers, who have rebuilt their idea of family around chosen relationships rather than inherited ones. The popularity of found family in fantasy is, in part, a literature catching up to its readership.
“A trope is not a shortcut. It is a contract. The reader knows the shape. The writer's job is to fill the shape with something true.”
Marriage of convenience
An older trope with a curious staying power. It works because it externalizes intimacy as a logistical problem before it becomes an emotional one. The characters share a household before they share anything else. The romance is then a slow recognition rather than a sudden one.
Second chance
The trope that does the most emotional work for older readers. Two characters who got it wrong the first time, given another version of each other to try again with. What it offers is a fantasy of revision: the idea that an earlier mistake is not necessarily final, and that the version of you who comes back is allowed to be different from the version who left.
All five of these will still be working in twenty years. The shapes are durable. The question, every cycle, is which writer fills them with something the reader has not seen before.