The movie is based on a young adult science fiction novel by Pittacus Lore, and it is the first book in the Lorien Legacies series: "I Am Number Four," "The Power of Six," "The Rise of Nine," "The Fall of Five," "The Revenge of Seven" and "The Fate of Ten." The final book, "United as One" was released in 2016.
Teresa Palmer went through three months, four hours a day, six days a week of exercises prior to filming. It included training for sword work, flips, sword fighting and wire work.
Alex Pettyfer and Dianna Agron started dating while filming this movie. They broke up a day after the film was released in theaters.
The studio tried to recreate the success of Crepúsculo (2008) with this film by marketing it as a "Twilight for boys." Although it hoped to be a box office success, the movie did not earn the hundreds of millions that the Twilight films (2008-2012) grossed.
Dianna Agron landed her role after a chance meeting with executive producer Steven Spielberg at a charity event. As a big fan of Glee (2009), Spielberg was seriously considering Agron for a prominent part when the chance encounter proved beneficial for both parties.