I am currently reading the book Wicked which is about the Wicked Witch of the West. What is the law regarding using somebody else’s character creation as the basis for your story?
Both tradmark law and copyright law are involved. However, I believe that L. Frank Baum’s books are all out of copyright, and I don’t believe that the Wicked Witch of the West is the subject of a trademark claim by anyone, so there would be no problem with using her in a story. But IANAL.
Indeed, since The Wonderful Wizard of Oz is in the public domain, you would not need permission to use the generic Wizard of Oz characters and personalities. However, if you wanted to use the familiar costumes of the characters as they appeared in the 1939 film, you’d have to obtain permission from Turner Entertainment, as the film is still copyrighted. Of course, since Wicked is a book, there’s really no regard in that case, although I’m sure the musical uses depictions of the characters that are different from those of the film.
Someone I know wrote a sequel to Asimov’s Foundation. He just changed all the names of characters and also planets. For example, my home of Trantor was renamed “Splendid Wisdom” and there was a race of people called “FrightfulPeople”. He did it to avoid copyright/trademark problems.
Actually, the musical does use depictions of the characters that were developed for the film. License to do so was obtained from Turner Entertainment.