Mary Shelley's novel, "Frankenstein; or, The Modern Prometheus," was published in 1818. Copyright protection was significantly different back then, and the book's copyright expired long ago.
This means that anyone can use the character and story of Frankenstein in their own creative works without needing permission or paying royalties.
However, it's important to note:
* Specific adaptations of "Frankenstein" might be copyrighted. For example, the 1931 film adaptation of "Frankenstein" is still under copyright.
* Original creations based on Frankenstein might be subject to copyright. If you create a new character or plot based on the Frankenstein mythos, your creation would be protected by copyright.
Ultimately, while the core story and characters are free to use, it's always a good idea to check if any specific adaptations you're interested in are still under copyright.