Joel Schumacher and David Kajganich had a falling out over all the changes Schumacher wanted in the script (not unlike what happened between Schumacher and Andrew Kevin Walker on 8mm - Delitto a luci rosse (1999)). The director won and re-wrote parts of the script himself.
Micheal Fassbender was excited to work with Joel Schumacher, whom he cites as one of his favorite directors.
Wentworth Miller plays an unnamed german soldier. He also starred in Prison Break opposite Dominic Purcell.
The production was filmed on locations in Romania (Bucharest and MediaPro Studios).