The Copyright status of the Oz books along with films affects their use by non-canonical authors, imitators, and creators of fan fiction.
All of the books of L. Frank Baum have passed out of copyright protection and entered the public domain with their plots and characters available for general use. The Wonderful Wizard of Oz, published in 1900 entered the public domain in 1956. Baum's other thirteen Oz books entered the public domain between 1960 and 1995. The firm of Reilly & Britton (later Reilly and Lee), which published all of the "Famous Forty" Oz books, only renewed certain titles depending on re-releases.
In general, the copyright law that prevailed through most of the 20th century protected published works for 28 years, with an option for renewal for another 28 years. The law was amended in 1976 and 1998 so the period of copyright protection was extended. As of 2022, this puts everything before 1927 in the public domain as 95 years after. There are ongoing discussions to lower the threshold, including one piece of legislation introduced in May that if passed as written would reduce it to 56 years or before 1966. This would be a significant revision but unlikely to pass because of corporate interests and the political background of it targeting Disney in particular.
Previous versions of the law, namely the 28 year minimum rule of 1909 has caused some confusion as there was a practice of reprinting Oz books many times without providing any date or edition information other than the original copyright date. This has bedeviled book collectors who have mistaken later versions for first editions. The company reprinted Baum's pre-1919 books with the "Reilly & Lee" imprint, instead of the "Reilly & Britton" imprint of the original editions with no other indication that the books were later editions. Canadian editions of the Oz books were issued by the firm Copp, Clark.
The situation is somewhat different for the works of Ruth Plumly Thompson as some have entered the public domain while others have not. Mark E. Haas ran into a copyright problem when he published his first Oz book, The Medicine Man of Oz in 2000. He used the character Herby the Medicine Man from The Giant Horse of Oz (1928), which is still under copyright protection until January 1, 2024. Robin Hess's first Oz book, Toto and the Cats of Oz, remains unpublished because of similar copyright considerations.
Thompson's earliest books, The Royal Book of Oz (1921), Kabumpo in Oz (1922), The Cowardly Lion of Oz (1923), Grampa in Oz (1924), The Lost King of Oz (1925), and most recently The Hungry Tiger of Oz (1926) are in the public domain. A few of Thompson's later Oz books did not have their copyrights renewed, and so entered the public domain before her earlier books. This is true of her last five "Famous Forty" books: The Wishing Horse of Oz (1935), Captain Salt in Oz (1936), Handy Mandy in Oz (1937), The Silver Princess in Oz (1938), and Ozoplaning with the Wizard of Oz (1939).
As of 2022, 10 out of Thompson's 21 Oz books are still protected with the rights held by the L. Frank Baum Family Trust.
As books published with copyright notice and later renewed between 1923-1963 retain protection for a total of 95 years. Thompson's remaining 'Famous Forty' works were all published between the years 1923 and 1934, so these works started to enter the public domain starting in 2019 with The Cowardly Lion of Oz and continuing with each successive book on an annual basis until 2030 with no further extensions.
There was a period of mixed copyright rules for the Magic Land books by Alexander Volkov which will now enter the public domain in 2048. This is because five of them were published in the Soviet Union before 1973 while modern Russia joined the Berne Convention in 1995. An author named Mary G. Langford went around this rule in 1969 when she translated Urfin Jus and His Wooden Soldiers into English as The Wooden Soldiers of Oz five years after its publication while March Laumer and Chris Dulabone released their own English versions of The Yellow Fog entitled The Yellow Fog of Oz and The Seven Underground Kings entitled The Seven Underground Kings of Oz in 1993. The rights for official translations were obtained by Peter Blystone.
For many of March Laumer's books, his publisher Vanitas Press in conjunction with Opium books decided to release PDF copies on a now defunct website that can still be accessed through the Wayback Machine, making them publicly available, if not public domain. This might have been done because the late author infringed on many copyrights, and perhaps avoided lawsuits by not being worth suing, plus publishing them in Hong Kong and Sweden. The Wikipedia page on this topic says: “he never saw any repercussions because his works were not considered significant enough to fight”.
There are some exceptions with modern authors allowing their books to appear on Project Gutenberg with fair use designation. Also Internet Archive has many copyrighted books available for viewing through a free account for usually an hour at a time.
Samuel Goldwyn purchased the film rights to the first Oz book in 1933. He sold the rights to the MGM studio in 1938, enabling the studio to create the classic 1939 film. The film rights to Baum's other 13 Oz books were purchased by Walt Disney in 1954. In the 1950s, Walt Disney himself attempted to develop a film, Rainbow Road to Oz, which would have been released while these copyrights were still valid but the Disney corporation eventually released the films Return to Oz (1985) and Oz the Great and Powerful (2013).
All of the silent films are in the public domain, with The Wizard of Oz (1925) entering in 1954.
The 1939 film will enter the public domain in 2035. Its long copyright holding by MGM and then Warner Brothers had impacts on later Oz adaptations as Return to Oz having to pay to use the Ruby Slippers. Copyright experts made sure Oz the Great and Powerful was distinct from the film in order to be made and some merchandise for Legends of Oz: Dorothy's Return had to be examined also.
Warner Bros. owning the exclusive rights to the 1939 film has led to direct-to-DVD films Tom and Jerry & the Wizard of Oz and its sequel Tom and Jerry: Back to Oz along with their series Dorothy and the Wizard of Oz, all of which are able to use trademarked likenesses of the 1939 film's characters.
Using settings and characters while copyright is valid has led to some issues:
- The Blue Emperor of Oz: First known fan-fiction
- The Laughing Dragon of Oz: Maud Gage Baum sued her own son Frank Joslyn Baum as Whitman Publishing settled out of court and promised Reilly & Lee they would not publish anymore Oz books.
- The Medicine Man of Oz: As mentioned on this page, this book about Herby the Medicine Man was published while the author previously faced legal threats from the L. Frank Baum Family Trust.
- How the Wizard Came to Oz/How the Wizard Saved Oz (1991-1993), novels by Donald Abbott: In the first volume, the characters Ku-Klip and Nimmie Amee appear, but couldn't be named because the copyright for The Tin Woodman of Oz did not expire until two years after the publication. In the second volume, King Pastoria's downfall is referenced, but happened differently than it did in Ruth Plumly Thompson's The Lost King of Oz, which remained in copyright until 2021.