To create the right physique for his role, Gong went on a diet for three months to reduce his body fat. He learned the Russian martial art Systema for the film's fight scenes, and performed car chases, rock climbing and skydiving at the Han River without using stuntmen.
The film was partly shot in Puerto Rico in April 2013.
Gong Yoo was eventually cast, and the protagonist's name "Ji Dong-chul" is similar to the actor's birth name, Gong Ji-chul.
Yoon Kyesang was originally cast in the lead role, but dropped out after costar Choi Min-sik left the project.