In order to include the ruby slippers as part of this film, Disney had to pay royalties to MGM, the studio which had produced The Wizard of Oz (1939). The ruby slippers did not appear in the original novel "The Wonderful Wizard of Oz"; they were invented for the 1939 film to better take advantage of the newly developed Technicolor process. Interestingly enough, in "The Wonderful Wizard of Oz," Dorothy wore a pair of magical silver shoes which were actually destroyed when she used them to return to Kansas. In the subsequent novel "Ozma of Oz," one of the books on which this film is based, Dorothy and her friends meet the Nome King who possesses a magical belt with properties similar to those of the silver shoes. Early drafts of the script for Return to Oz reflect this, with the Nome King possessing a magical ruby belt which had been created from the ruby slippers.
Director Walter Murch invited friend George Lucas to visit the set one day. During that visit Lucas wandered to different sound stages where he came across producer Rick McCallum working on a small film. The two became friends and later collaborated on the "Star Wars" prequels.
Fairuza Balk actually performed most of the film barefoot, as she found her black shoes uncomfortable, and the ruby slippers were very fragile and easily damaged. Thus, the actress only wore shoes when they would be visible on camera.
Fairuza Balk's ruby slippers were specially handmade with imitation rubies and rotoscoped in post-production to give them a magical look. The rubies were actually glass beads imported from Austria and individually attached to the shoes with a special spray adhesive. This later proved problematic, as the hot stage lights melted the adhesive, and the young actress' fidgety movements would often knock the beads off. Tired of chasing after detached beads, the wardrobe staff finally ordered the shoes to be worn only when visible on camera. Balk confirmed to a fan, via Twitter in September of 2017, that she got to keep one pair of the ruby slippers she wore in the film.
The movie is based on the second and third Oz books: "The Marvelous Land of Oz" and "Ozma of Oz". Elements from the former include the introduction of Jack Pumpkinhead, the witch Mombi and her powder of life, the conquest of the Emerald City, the escape by flying sofa, and the search for Princess Ozma. From the latter comes the return of Dorothy, the talking chicken Billina, the wheelers, the discovery of Tick-Tock, a princess with interchangeable heads, the introduction of the Nome King, and the ornament room.
Walter Murch never intended for this film to be viewed as a direct sequel to The Wizard of Oz (1939); rather, he intended it as a partial sequel with some direct references (the ruby slippers, actors playing characters in Oz and the "real world") but in closer similarity to the Oz novels (the appearance of the Oz characters, Oz being a real place as opposed to a dream). The misconception that the film was ever meant to emulate the MGM musical probably contributed to its failure at the box office.
Several major characters from the Oz books make cameos in the final parade scene, including: The Shaggy Man, The Patchwork Girl, Prof. H.M. Wogglebug, T.E., Santa Claus, Tommy Kwikstep, Button Bright, and The Musicker.
When the desolate Emerald City is first seen, there is a close-up of a bas relief portrait of a creature with a lion's head, a monkey's body, and an eagle's wings. This is a faithful reproduction of John R. Neill's portrait of the aptly named creature Li-Mon-Eag, which appeared on the back cover of 'The Magic of Oz', an Oz tale by L. Frank Baum, first released mere weeks after the latter's death in 1919.
Several additional scenes filmed for the opening Kansas sequence, including a face-painting scene between Dorothy and Aunt Em, Billina running through the farmhouse kitchen and Uncle Henry reading newspaper clippings detailing Dorothy's disappearance after the cyclone, were cut from the final film.
To create the stop-motion puppets of the nomes, Nicol Williamson and Pons Maar were photographed against a background grid. Will Vinton (of "Claymation" fame) then watched the footage frame by frame and manipulated the puppets based on the movements and expressions of the actors.
In the movie Mombi enchants Ozma into the mirror after the Nome king promised Mombi the heads of the dancing girls if she keeps Ozma a secret. In L. Frank Baum's original novel "The Marvelous Land of Oz," it is the wizard who brought the baby Ozma to Mombi, who hides the girl away in a transformed state.
The Scarecrow was originally supposed to have a fully articulated animatronic face, akin to that of the Gump, however budget cuts forced the puppeteers to reduce his face to a series of masks with fixed expressions.
Disney actually fired director Walter Murch about a week into production due to budget concerns. The studio found dailies lacking and Murch's slow shooting pace disheartening. Much contacted friends Francis Ford Coppola, Steven Spielberg and George Lucas for help, and all three directors lobbied Disney to rehire Murch. Lucas even offered to take over directing himself should Murch fall behind schedule. Murch finished the film on schedule, though while in post-production studio management changed. The new executives had little faith in the movie, and doomed it with limited promotion and a short theatrical run.
Pons Maar who plays the Lead Wheeler, one of the asylum orderlies, and provides the voice of the Nome Messenger also served as a movement coach on the film, working to develop the postures and movements of the Scarecrow and Jack Pumpkinhead.
The character of the movie's version of Princess Mombi is based on that of Princess Langwidere in "Ozma of Oz", who ruled the Land of Ev, across the Deadly Desert from Oz. As in the movie, Langwidere had interchangeable heads and locked Dorothy in the tower room of the palace.
Vince Cross composed a tie-in song "Return to Oz" which was released as a single on the Cherry Lane label, sung by Victoria Wood. It was not used on the soundtrack and is not on the official soundtrack album.
Leo McKern, who bore a strong resemblance to the character in the original Oz illustrations, was the first choice for the role of the Nome King. McKern turned down the role due to scheduling conflicts.
In the movie Mombi enchants Ozma into the mirror after the Nome king promised Mombi the heads of the dancing girls if she keeps Ozma a secret. In L. Frank Baum's original novel "The marvelous land of Oz," it is the wizard who brought the baby Ozma to Mombi requesting that she be concealed from Queen Jinjur; Mombi disguises the girl's identity by turning her into a boy called Tip.
This film has some throwbacks from the 1939 Wizard of Oz film. Examples include Dr Worley and Nurse Wilson having evil Oz counter parts where the Nome King and Mombi represent Dr Worley and Nurse Wilson respectively. Like Tin Man Tick Tock keeps freezing on the spot and at one point cries as well. Like how the Witch of the West has flying monkeys and Winkie Guards as her minions, Mombi similarly has the Wheelers who are original characters in the film as her minions. Belina like Toto serves as Dorothy's pet. And more famously the Nome King says the ironic line 'There's no place like home'.
In the movie, the interior of the Nome King's Mountain looks like Fingals Cave, (near Scotland) as it is made of hexagonal basalt columns (even the floor of the cave). This kind of Basalt columns are also found on the Giant's Causeway located off of Northern Ireland.
While filming the sequence near the end of film where Dorothy rides atop the Cowardly Lion, actress Fairuza Balk became so overwhelmed by the temperature (in excess of 110 degrees Fahrenheit) that she passed out on the sound stage.
During the scene in Dr. Worley's office, Dorothy is telling the story of how the Tin Woodsman came to lose his legs. Dorothy starts to say the word 'hacked' ... but this was hastily dubbed to 'cut' as the original line was deemed too strong for younger viewers.