The series was made with the full cooperation of George Lucas, who donated the rights and allowed the use of sound effects and music from the films. As with other Legends material, only material matching what was featured in the original film is considered canon, but many elements of the story first featured in the radio broadcasts were later referenced in other Legends stories. Many of the actors involved in the movie were unavailable to reprise their roles (Harrison Ford, for instance, was committed to Raiders of the Lost Ark), but Mark Hamill and Anthony Daniels returned to reprise Luke Skywalker and C-3PO, respectively.