The show was originally supposed to take place in a type of shopping centre with each of the Misfits working in a different shop on Saturdays. It was changed to the show as it is now known after E4 told Howard Overman to make it more "urban".
Antonia Thomas was originally reluctant to take the role of Alisha Daniels due to the heavy amount of sexual activity involved in the part. However, she changed her mind when she read the script further, met with Overman and found that the character had far more depth than originally thought. Thomas also joked in an interview that when Overman met with her and asked if there were any requests for character development in Series 2 she answered "less inappropriate sexual things to do on screen."
Joseph Gilgun's character Rudy Wade was brought in after Robert Sheehan's departure after Series 2. However, Howard Overman decided he didn't want another Nathan, so decided to make Rudy 'more emotional' which is present in the character's power of emotional induced multiplication.
Karla Crome and Nathan McMullen both auditioned for other characters before being chosen to play Jess and Finn respectively. Crome originally auditioned for Curtis' love interest Nikki and McMullen, a minor villain in Series 3.
Joseph Gilgun got '23456' tattooed on to his chest in honor of his time on the series. Each number represents a different cast member from Series 3, including Matthew McNulty whose character of Seth was becoming a regular.
Over the course of the show's first three seasons, each character was given their own Twitter accounts, supervised by writer Howard Overman himself. Initially used for Viral Marketing, these accounts were also used to provide extra information about each character and were key to the 'Guy in the Mask' arc during the show's second series. They also bridged gaps between series' building up to the 'Vegas Baby!' and 'Erazer' spin-off short films.
Iwan Rheon (Simon), Michelle Fairley (Louise Young), Ellie Kendrick (Helen) and Nathalie Emmanuel (Charlie) have all starred in Game Of Thrones (2011-) as Ramsay Bolton, Catelyn Stark, Meera Reed and Missandei.
The trivia items below may give away important plot points.
The powers attained after the storm represent flaws within the characters. In season 1, Alisha, who has casual sex without regard to others, is given the power of hyper-sexual arousal. Curtis, who constantly regrets his failed athletic career, can now reverse time. Kelly, conscientious of how people saw her, has the ability to read others' minds. Simon, an introvert can now become invisible. Nathan had a "live for today" attitude and so becomes immortal.
Iwan Rheon, as with most of the other cast, were disappointed with their power change in Series 3. Antonia Thomas, however, stated that she was not disappointed with the change because "her old power was shit".