Epistolary means written in the form of letters. An epistolary novel tells its story entirely through letters between characters, like when you're reading someone's mail to discover what happened. Instead of a narrator describing events, you experience the story through the characters' own written words to each other.

One famous epistolary novel is Dracula by Bram Stoker, which unfolds through letters, diary entries, and newspaper clippings. Another is The Guernsey Literary and Potato Peel Pie Society, where the entire story emerges from letters exchanged between a writer and the members of a book club. These books feel intimate because you're reading the characters' private thoughts, exactly as they chose to express them.

Before telephones and email, letters were how people communicated across distances, so epistolary novels captured how people actually stayed in touch. Today, some modern stories use emails, text messages, or social media posts in a similar way. When a story is told through these written exchanges rather than traditional narration, it's using an epistolary format.