At the 2008 Wondercon, Emmerich mentioned the fiction of Robert E. Howard as a primary influence for the film's setting, as well as his love for the film Quest for Fire and the book Fingerprints of the Gods.
Emmerich indicated that Robert E. Howard's fictional world served as a key inspiration for the film's setting, and he also expressed appreciation for the movie "Quest for Fire" and the book "Fingerprints of the Gods".