In 2014, the Hong Kong newspaper Apple Daily reported that director Ringo Lam would return to directing with an investment from the Mei Ah Entertainment Group with production set to begin in June. On the first day of filming, Lam collapsed due to a heat stroke. He stayed with the project to keep filming. In 2014, the film's titled changed from Hustle to Wild City. Louis Koo has stated, Lam insisted that the actors perform their own stunt work in the film to maintain realism. Variety reported that Lam was in post-production on the film by March 23, 2015.