Based on the novel "The Wave" by Todd Strasser (under the pen name Morton Rhue), a fictionalized account of the "Third Wave" teaching experiment by Ron Jones that took place in a Cubberley High School history class in Palo Alto, California in April 1967.
Ron Jones has stated that he thinks the film is much closer to the actual events of the experiment than the novel by Morton Rhue/Todd Strasser.
Much like Napola, the film was partly inspired by Gansel's grandfather, with whom Gansel had a lot of fights when young because his grandfather used to tell him he was supportive of the Nazi government when they where in power. It was not until Gansel's grandfather told him of his ambition to become an artist - which family poverty could only avail him towards joining the National Political Academy (NAPOLA) instead - that Gansel understood the lure of fascism was all about seduction and psychology. This laid the basis for the film and its themes.
Dennis Gansel has stated that he will never make another film about national socialism again after The Wave as he feels he has said all he has to say about the subject.
Ron Jones, the initiator of the original experiment, attended the film's world premiere at Sundance Film Festival.
The students are repeating a play, in which only "The Wave" students have roles after Karo is fired. In this play, 'Der Besuch der alten Dame' by Friedrich Durenmatt, an old woman who was exiled from her village by her fellow inhabitants comes back after many years. Having lost her billionaire husband and inherited his wealth, she has her revenge by leading all the villagers to kill her former lover who didn't help her. One of the themes is the group action and how people lose their personalities in a group. This mirrors the teacher's experience, who lead people into acting and losing personalities.
While the crew managed to get numerous businesses to allow them to spray the "Wave" onto their stores, or to attach the stickers, they were not allowed to paint the scaffolding, making that the only CGI-Shot in the whole movie.
Rainer Wenger was named after a beloved teacher named Rainer who worked in Dennis Gansel's school and whom the students (against German custom) refereed to by first name.
Ron Jones, teacher and writer of the original short story and teleplay The Wave appears in the film as a diner sitting outside the restaurant that the members of the Wave tag with their logo stencil.