These fictional universes are free to explore for writers looking to put their own spin on a classic story.

The legality of fanfiction has always been murky, with questions about how much of a story can be used and how stories can be shared and posted. But some fandoms are in the public domain, meaning they're open to reimagining by writers. (Just remember that only the books are public domain—not the movies or other adaptations.)

Here are a few of our favorite book worlds that are public domain...

Pride & Prejudice

Jane Austen's quintessential enemies-to-lovers tale entered the public domain in 1998. That means Elizabeth and Darcy are free to be remixed by today's creatives. (And it has been already—Seth Graham Smith's infamous Pride and Prejudice and Zombies mashup became a hit book and a 2016 film!)

Sherlock Holmes

Fans of the stern detective and his partner Watson will be happy to know that most Sherlock stories are public domain. Although Enola Holmes recently made headlines with a copyright dispute with Sir Arthur Conan Doyle's estate, even that will soon be a moot point as his final stories are set to enter the public domain on January 1st, 2023.

The Little Mermaid

Hans Christian Andersen's novel The Little Mermaid is in the public domain. Just be aware that the Disney film version is still off-limits, so original characters like Sebastian and the names of Eric, Ariel, and Ursula are still copyrighted.

The Land of Oz

The Wonderful Wizard of Oz was written by L. Frank Baum in 1900, so the fantastical land in the book is open to creative reimagining. That means Dorothy, Toto, and the Wicked Witch of the West are free game. (So maybe you could write the next Wicked!)

Romeo & Juliet

Shakespeare's classic drama about forbidden love has so many great reimaginings already—broadway musical and movie West Side Story, bestselling dark YA novel These Violent Delights, and lesbian romance By Any Other Name to name a few—but it's a classic for a reason! And since it was written in the late 1500s, its copyright is well and truly expired.

The Legend of Sleepy Hollow

The gothic Washington Irving tale of Ichabod Crane and the headless horseman is full of classic horror imagery for authors. With Ichabod's job as a schoolmaster, we think it's just begging to be redone through a dark academia lens.

Did we miss any good ones? Tell us in the comments...