Land of Oz
The book has had 39 official sequels (with the original these are generally called "The Famous Forty"), 13 of them by Baum. Here's a list of titles:
Oz books written by L. Frank Baum
- The Wonderful Wizard of Oz (1900)
- The Marvelous Land of Oz (1904)
- Ozma of Oz (1907)
- Dorothy and the Wizard in Oz (1908)
- The Road to Oz (1909)
- The Emerald City of Oz (1910)
- The Patchwork Girl of Oz (1913)
- Tik-Tok of Oz (1914)
- The Scarecrow of Oz (1915)
- Rinkitink in Oz (1916)
- The Lost Princess of Oz (1917)
- The Tin Woodman of Oz (1918)
- The Magic of Oz (1919)
- Glinda of Oz (1920)
- Little Wizard Stories of Oz (a collection of six short stories L. Frank Baum wrote about the characters in Oz. Was published in separate booklets in 1913, the same year as The Patchwork Girl of Oz, then as a collected edition in 1914, the same year as Tik-Tok of Oz.)
Oz books written by Ruth Plumly Thompson
- 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)
- The Hungry Tiger of Oz (1926)
- The Gnome King of Oz (1927)
- The Giant Horse of Oz (1928)
- Jack Pumpkinhead of Oz (1929)
- The Yellow Knight of Oz (1930)
- Pirates in Oz (1931)
- The Purple Prince of Oz (1932)
- Ojo in Oz (1933)
- Speedy in Oz (1934)
- The Wishing Horse of Oz (1935)
- Captain Salt in Oz (1936)
- Handy Mandy in Oz (1937)
- The Silver Princess in Oz (1938)
- Ozoplaning with the Wizard of Oz (1939)
Oz books written by John R. Neill
- The Wonder City of Oz (1940)
- The Scalawagons of Oz (1941)
- Lucky Bucky in Oz (1942)
Oz books written by Jack Snow
- The Magical Mimics in Oz (1946)
- The Shaggy Man of Oz (1949)
Oz books written by other writers
- The Hidden Valley of Oz by Rachel Cosgrove (1951)
- Merry Go Round in Oz by Eloise Jarvis McGraw and Lauren Lynn McGraw (1963)
Additional Oz books by the earlier writers
- Yankee in Oz by Ruth Plumly Thompson (1972)
- The Enchanted Island of Oz by Ruth Plumly Thompson (1976)
- The Forbidden Fountain of Oz by Eloise Jarvis McGraw and Lauren Lynn McGraw (1980)
- The Wicked Witch of Oz by Rachel Cosgrove (1993)
- The Runaway in Oz by John R. Neill (1995)
- The Rundelstone of Oz by Eloise Jarvis McGraw (2001)
Sequels to the above
- Mister Tinker in Oz by James Howe(1985)
- The Ozmapolitan of Oz by Dick Martin (1986)
- Paradox in Oz by Edward Einhorn (1999)
- The Unknown Witches of Oz by Dave Hardenbrook (2000)
- The Emerald Wand of Oz by Sherwood Smith (2005)
- The Living House of Oz by Edward Einhorn (2005)
- Trouble Under Oz by Sherwood Smith (2006)
- Silver Tower of Oz by Margaret Baum (2011)
The "Alternative" Oz
A number of unauthorized sequels, alternate takes on Oz, and out of continuity tales. The following list may be incomplete:
- The Laughing Dragon of Oz by Frank Joslyn Baum (1934)
- Tales of the Magic Land by Alexander Melentyevich Volkov (1939-1975)
- A Barnstormer in Oz by Philip José Farmer (1982)
- Return to Oz by Joan D. Vinge (1985). Novelization of the film.
- Dorothy of Oz by Roger Stanton Baum (1989)
- The Rewolf of Oz by Roger Stanton Baum (1990)
- The SillyOZbuls of Oz by Roger Stanton Baum (1991)
- The SillyOZbul of Oz and Toto by Roger Stanton Baum (1992)
- The SillyOZbul of Oz and the Magic Merry-Go-Round by Roger Stanton Baum (1992)
- Was by Geoff Ryman (1992)
- Lion of Oz and the Badge of Courage by Roger Stanton Baum (1995)
- Wicked: The Life and Times of the Wicked Witch of the West by Gregory Maguire (1995)
- The Dark Tower IV: Wizard and Glass by Stephen King (1997)
- The Green Star of Oz by Roger Stanton Baum (2000)
- Toto in Candy Land by Roger Stanton Baum (2000)
- The Wizard of Oz and the Magic Merry-Go-Round by Roger Stanton Baum (2002)
- Toto of Oz and the Surprise Party by Roger Stanton Baum (2004)
- Son of a Witch by Gregory Maguire (2005)
- The Oz Odyssey by Roger Stanton Baum (2006)
- A Lion Among Men by Gregory Maguire (2008)
- Oz Squad: March of the Tin Soldiers by Steve Ahlquist (2011). Novel based on the Oz Squad comic book series.
- Out of Oz by Gregory Maguire (2011)
The first 16 books are now public domain. As the list above testifies, there are also many unauthorized sequels, including the award-winning book Wicked (and the equally-award-winning Broadway musical that was based on it), Alexander M. Volkov's Tales of the Magic Land and Philip Jose Farmer's A Barnstormer in Oz.
Interestingly, Walt Disney saw possibilities in Oz, and at one time considered making an animated feature based on the stories. He bought the movie rights to 11 of Baum's books, but for reasons that were never made clear later canned the project well along into the pre-production stages. The Walt Disney Company kept the rights until the 1980s. You can read more about the project here. It features interestingly faithful designs for characters that didn't appear in the 1939 movie, like Princess Ozma and Patchwork Girl, clearly based off the Neill illustrations. Oddly enough, the Disney Books on Tape, which mostly just adapted the movies (with some exceptions), had one for this story.
Check out the Character Sheet.
Most adaptations focus on the first book of the series; for a list of those, see The Wizard of Oz. One adaptation that included some of the later books was the 1986 anime The Wonderful Wizard of Oz, which adapted four of the first seven books. The 1985 film Return to Oz is a loose adaptation of the second and third novels in the series.
- Clockwork Creature: General Tik-Tok may have the distinction of being the first depiction of a clockwork-powered robot in fiction. He's also the Ur Example of the loyal Robot Buddy and We Can Rebuild Him.
- Cyborg and Unwilling Roboticisation: Possibly the earliest example of a full-body-replacement cyborg in modern literature is the Tin Woodsman from The Wonderful Wizard of Oz. He was once a perfectly ordinary human being until a witch cursed his axe, which repeatedly attacked him to chop off his body parts. He gradually replaces his missing body piece by piece with tin prosthetics -- until essentially all that was left was a mind in a tin shell. 
- Robo Speak: In "Ozma of Oz," Tik-Tok, a wind-up robot (though not called that since the word was not yet in circulation) who speaks in mon-o-tone and in-flex-i-ble ca-dence.
- World Building: Maps by Baum depict Oz's four regions and its neighboring kingdoms. The worldbuilding came about because of fans clamoring for more stories and places to explore. (Continuity Snarl ensued.)
Books in the Famous Forty with their own trope pages include:
The remaining books in the Famous Forty include examples of:
- Abuse Is Okay When It Is Female On Male: Jinjur, having failed to take over Oz, appears in a later cameo, placidly explaining that she is content with her quiet life with her husband -- and her husband is nursing a black eye because he had milked the cows in any order she did not approve of.
- Adaptation Dye Job: Dorothy and Ozma's hair color varies from artist to artist and medium to medium. For instance, in their first appearances, Dorothy was a brunette and Ozma a blonde, but later illustrations show a black-haired Ozma and a blonde Dorothy. Long-time Oz illustrator John R. Neill Lampshaded this with one drawing, showing his blond version of Dorothy looking at a statue commemorating W.W. Denslow's brunette.
- Adaptation Overdosed: While the movie is better remembered, the books have a lot adaptations ranging from comic books to film to cartoons made in Russia.
- All Just a Dream: Averted Trope in the original books. Baum himself stated that the land of Oz is located somewhere in the world, it's just surrounded by impassable deserts. Indeed, The Emerald City of Oz, which Baum originally intended as the conclusion to the series, has Dorothy moving to Oz permanently along with her aunt and uncle.
- Backstory: In response to fan mail asking question about Oz and its characters. There's just enough info to give an idea what Oz was like before Dorothy came to it.
- Baleful Polymorph: The Nome King uses the Magic Belt, and later his own magical powers, to turn people into objects. Dorothy later uses it to turn a villain into a dove. Red Reera uses her Yookoohoo abilities to turn herself and her pets into different creatures at a whim. (She also transforms some guests, but only after getting permission.) The magic word in The Magic of Oz also allows characters to inflict this on one another.
- Big Bad: The Nome King.
- Card-Carrying Villain: The Nome King again.
- Cats Are Mean: Both Eureka and the Glass Cat have their moments of this.
- Clockwork Creature: Tiktok the Machine Man. You have to wind him up every few days or he'll run down.
- Continuity Drift: Coherent continuity isn't one of the Oz books' strengths. Probably deliberately, as Baum, being no Tolkien, was much more interested in exploring his fairyland than keeping track of it, and was only writing the sequels anyway as a result of fan clamour for more. The eventually-insanely-convoluted explanation for how the Wizard became the ruler of Emerald City is perhaps the best-known result of this. Other fanbase-dividing changes to the setting include the issues of money (first it existed, then it didn't), death (first it existed, then it didn't), and whether or not Emerald City had its color because of the city's construction or if the green tinted glasses are still being used.
- Crap Saccharine World
- Cute Shotaro Boy: Button-Bright in the Baum books.
- Deadpan Snarker: Surprisingly, the narrator in The Wonderful Wizard of Oz shows this at times.
"For," they said, "there is not another city in all the world that is ruled by a stuffed man." And, so far as they knew, they were quite right.
- Deus Ex Machina: The Road to Oz has one of the more infamous examples of this.
- The Ditz: Button-Bright, in spite of his nickname, is actually kind of dim. He asks a lot of questions, but he's not good at taking the answers to those questions and making connections or thinking critically about it.
- Domed Hometown: The island of the Skeezers in Glinda of Oz is covered by a glass dome, and can be submerged in or raised above the surface of the lake with a spell known only to the queen.
- Early Installment Weirdness: The Oz of the first two books is notably different from the Oz in subsequent books. A lot of this can, and has, been explained and justified by Ozma coming to power and radically changing things.
- Everythings Better With Bunnies: Bunnyburg; Glinda apparently loves rabbits.
- In the last of the Famous Forty. Merry-Go-Round in Oz, it's revealed that the Easter Bunny lives in Oz as well.
- Everything's Better with Princesses: Princess Ozma, although given the political reality of Oz she might be really an Empress. Dorothy herself became a Princess in one of the later books.
- Expansion Pack World: The first two books, "The Wonderful Wizard of Oz" and "The Marvelous Land of Oz" were originally meant to be stand-alone stories. Fans of those books kept asking Baum questions about Oz. So Baum kept writing the Oz books to answer those questions and laid down some backstory.
- Face Stealer: Princess Langwidere, who can change her head at will, and wants to trade Dorothy's head for one of her own.
- Fairy Tale: Wizard of Oz was Baum's attempt to write an "American" fairy tale.
- Fanfic: Outside of the famous forty, there have been fan fics written about the land of Oz and its characters over the years.
- A Barnstormer in Oz by Philip Jose Farmer is one such example. This story is the adventures of the son of Dorothy. The novel is done from a more adult point of view.
- A series of graphic novels about Oz by Eric Shanower.
- Wicked -- The musical Wicked relies much more heavily on the movie's version of events. Gregory Maguire's original book tends to have more to do with Baum's original series, with the characters of (green-skinned) Elphaba and (Northerner) G(a)linda being major exceptions. It equivocates on the silver shoes/ruby slippers question.
- Then there's the prominent Oz sequence in Robert A. Heinlein's novel The Number of the Beast.
- The Indie Game Emerald City Confidential is this.
- Fan Sequel: Various authors throughout the years have been adding on to the Oz series. Focusing on the origins of various secondary characters was a popular choice. Considering the amount of consistency with Baum himself, any of them could probably be considered canon. Yes, this probably involves the Wicked series too.
- Fantasy World Map: One of the earliest examples. Baum apparently used Chinese geomancy (Feng Shui) to make the map. It made west and east look inverted. The map makes a lot of sense if the POV is in the Emerald City, looking southward. See this map.
- Flower in Her Hair: Princess Ozma.
- Forbidden Zone: The Deadly Desert.
- Franchise Zombie: Baum had only meant to write one or two Oz sequels and then move on to other projects, but the popularity of the books, coupled with his own financial issues and the fact that all of his non-Oz books (apart from Father Goose, which he wrote before the first Oz novel and which was his first success) were flops, forced him to keep writing Oz books for the rest of his life, long after he had lost interest in them.
- Giant Flyer: The Gump and the Ork.
- Have a Gay Old Time: The Dicks of Dicksy Land are "queer" about their shoes and their diets.
- In The Tin Woodman of Oz, the Scarecrow and Tin Woodman call their young traveling companion Woot the Wanderer "our boy friend." Hmmm...
- Heart Trauma: In The Scarecrow of Oz, the evil witch Blinkie freezes the heart of Princess Gloria of Jynxland to keep her from loving the gardener's boy, Pon. When the princess' heart has frozen, she not only acts ice-cold towards everyone but seems incapable of any real emotion.
- Heterosexual Life Partners: The Scarecrow and the Tin Woodsman; Dorothy and Ozma.
- Hurricane of Puns: Baum liked puns. Ruth Plumly Thompson liked them even better.
- Intergenerational Friendship: Trot and Cap'n Bill
- Immortality: After the first few books, everyone in Oz has this, though it drifts between Type II and Type VI without the aging.
- The Kingdom: The Kingdom of Oz is really an Empire under Princess Ozma but it does have kingdoms within kingdoms. One of the kingdoms (the Winkies in the West) is ruled by an Emperor. Apparently he just likes the title, since other characters have pointed out the problem with this as early as the second book.
- King Incognito: Ozma's father and Ozma herself
- Level Ate: Several examples in Oz, e.g., Bunbury.
- Loads and Loads of Characters: A frequent plot device of the later books especially is to either send the established quartet off on a quest through remote and uncharted corners of the land, or have the remote uncharted etc.'s inhabitants quest off towards the Emerald City. The net result is an entirely new assortment of characters in each book, in most cases complete with backstories. Oz books written in years after Baum's death introduced still more characters this way.
- Long Running Book Series
- Made a Slave: In Ozma of Oz, the Nome King justifies turning the queen of Ev and her children to ornaments because they had been sold to him as slaves, and it was more humane than slaving in the mines.
- Magic A Is Magic A: Both averted and played straight. Although magical characters like Glinda and the Wizard display New Powers as the Plot Demands, most magical artifacts in the series have clearly defined rules and limited powers, as opposed to being Green Rocks or a Green Lantern Ring. Notable examples include the Golden Cap from the first book, Ozma's Magic Picture, Glinda's Book of Records, and the Powder of Life. The Nome King's Magic Belt is probably the biggest exception.
- Magical Land: Oz and the countries around it.
- The Magocracy: The Quadling (South) Country of Oz is this, being ruled by Glinda. The whole Land of Oz becomes this after Princess Ozma takes the throne.
- Massive Multiplayer Crossover: In The Road to Oz, when characters from several of the author's other books gather at Ozma's birthday party.
- Medium Awareness: The Shaggy Man: "No one can know that, except for the person who's writing this story."
- Mix-and-Match Critters
- The Kalidahs, creatures that have the head of a tiger and a body of a bear.
- The two characters who transform themselves into Li-Mon-Eags (lion-monkey-eagles) in The Magic of Oz Invoked Trope this trope, since they are trying to win the loyalty of all the wild beasts in Oz and want to avoid looking partisan.
- And of course the winged monkeys.
- The Needless: The Sawhorse is a saw horse which Pip brought to life using Old Mombi's life-giving powder. Later Jim the (real) Cab Horse comes to Oz, and tries to convince the Sawhorse that being a meat and bones horse is better than being a wooden horse magically brought to life, but all the examples that Jim gives actually come out in the Sawhorse's favor: for example Jim says that he can bleed and that's good because people can know where he's hurt - the Sawhorse points out that he doesn't get hurt, so he doesn't need to bleed. Jim is the only animal from our world who, having come to Oz where he can talk, begs to go back to the real world where he's just a dumb animal.
- Non-Human Sidekick: Lots of them.
- Offered the Crown: Happened quite often, especially if the book featured a villainous king or queen (almost invariably deposed and replaced with a heroic character or a subordinate who had managed to Pet the Dog).
- The Other Darrin: Not with a character in the book, but with the illustrators (switched to John R. Neill after The Wonderful Wizard of Oz) and later with the author. There is one brilliant illustration in Road To Oz (illustrated by Neill) in which Dorothy looks at a tin statue of herself, appearing "as she was when she left Oz." The tin statue shows Dorothy in the original illustrator's style, but the Dorothy studying the statue is in Neill's style.
- Patchwork Map: A good look at the map of Oz and its surrounding lands screams "PATCHWORK!" at the reader. It's understandable since Baum made it up as he went along.
- Popcultural Osmosis: The Oz books arguably have a more of a pop cultural impact than the movie.
- Princesses Rule:
- Ozma rules as Princess, although she's really more of an Empress.
- In Ozma of Oz, Princess Langwidere of Ev is a justified example, as she's merely acting as ruler until the return of the Royal Family.
- In Tik-Tok of Oz, Ozga, the Rose Princess, would have been one of these, except that her people rejected her as they wanted a male ruler.
- Public Domain Character/Canon Fodder: The first 16 books are public domain and that's still enough material for Fanfics and different takes on Oz. Even now there are new comics based on Land of Oz and sometimes they Crossover with other public domain characters, like Alice from Alice in Wonderland.
- Princess Classic: Princess Ozma
- Reality Writing Book: Glinda the Good Witch of the South has a book in which is written everything that happens in Oz, as it happens. If she needs to find out what happened at any given time she just looks it up.
- Recursive Canon: Later Oz books treats Oz as a real place, and presents the books as based on real events, recounted to the author by Dorothy. New visitors to the land (such as Betsy Bobbin and Trot) are often familiar with the land of Oz and its inhabitants long before they even set foot in the land, because they've read the previous books.
- Retcon: The story how Ozma's father was overthrown was changed to make the Wizard less of a villain.
- Robo Speak: Tik-Tok's way of speaking and one of the earliest examples of this trope.
- Romantic Two-Girl Friendship: Dorothy and Ozma. Morning kisses, and Ozma makes Dorothy her Princess.
- Royal Blood: Princess Ozma
- Schizo-Tech: Oz is a fairyland with wind up robots (Tik-Tok) and cyborgs (The Tin Woodsman).
- Science Marches On: Note to readers of The Patchwork Girl of Oz: Building your house out of solid radium is a really bad idea.
- It gets better. The character in question actually says "It is a medicine, too, and no one can ever be sick who lives near radium."
- Shaggy Dog Story: The Patchwork Girl Of Oz could easily be this. The characters journey to find the ingredients for a magical concoction that will save two people who have been petrified. They find all of them but one, which should have been the easiest; the wing of a yellow butterfly. But the lands on which yellow butterflies live are ruled by the Tin Man, and he won't let a butterfly come to any harm, rendering the quest pointless. And then Glinda just fixes the people by magic anyway, making it even more so. The characters even met with Dorothy and Ozma earlier on, and they didn't even suggest this possibility, or mention the Tin Man's feelings about living things.
- Shining City: The Emerald City.
- Single Palette Town: The Emerald City and each of the four quadrants of Oz: East, Munchkins, blue; West, Winkies, yellow; North, Gilikins, purple; South, Quadlings, red.
- Sugar Bowl
- Threshold Guardians:
- The Guardian of the Gates of the Emerald City
- The Iron Giant in Ozma of Oz
- Touched by Vorlons: The inhabitants of the Valley of Voe who eat the dama-fruit
- Trapped in Another World: Many early Oz books had this as the plot.
- Tunnel King: The Nome King
- Underwater City: The Skeezers' island in Glinda of Oz, when submerged.
- Wacky Wayside Tribe: Plenty of examples in Baum's books.
- White Bunny: Glinda created the city of Bunnybury specifically to be home to all the pink-eyed white rabbits of the forest.
- Wicked Witch: The Good Witches of the North and South are a subversion. A special subversion, as the notion of a good witch was alien at the time. In later books, it is revealed that there were two other Wicked Witches: Mombi, who kept Ozma imprisoned but was stopped from gaining power over Gillikin Country by the Good Witch of the North, and a fourth witch who was stopped by Glinda in the south.
- Witch Species
- The Wonderland: Oz itself, with talking scarecrows and robots before there were robots...
- World Building: Baum's Land of Oz predates other fictional lands like Middle-Earth and Narnia.
- You Imagined It: Notable in that the characters who insist this (chiefly Aunt Em and Uncle Henry) are, in fact, wrong.
- The tinsmith kept his old head in a closet, where, due to the no-death nature of Oz, it remained sentient, desiring nothing to do with the Tin Man when he returned to retrieve it.