The character of Adam Mitchell was first conceived, along with Henry van Statten, during Russell T Davies' 2003 pitch to the BBC, in a story heavily based on Robert Shearman's audio play Jubilee, which would later form the base for the episode "Dalek". It was always the intention of the production team for Adam to join the TARDIS after Rose developed a liking for him. To play this role Langley was chosen, mostly because of his role on Coronation Street as Todd Grimshaw. He had auditioned for the role on the same day as doing publicity for his leaving storyline in Coronation Street. Reacting to his casting Langley, remarked that "I couldn't have asked for a better next role because Doctor Who is another great institution." Langley describes Adam as "a bit nerdy" and states of his character's attraction to Rose that "she's a very pretty girl and Adam hasn't seen any girls for a long time."
