Many lines were improvised during filming. For example, Jeff's line, "You ever see a demon praying mantis before? They real boy!" was made up on the spot. David Spadora (Walt) started laughing and they had to cut the scene.
Another improvisation happens when Jeff and Walt are firing guns in slow-motion. Walt's character goes overboard and starts crying. This was improvised during the take and used in the final cut of the film.
The spell battle scene was filmed at 4am in 55 degree fahrenheit weather.
The filming location is a real farm High Bridge, New Jersey, only a 5 minute drive from director Taylor Morano's house. The farm owners agreed to let the filmmakers use the farm for a week at no cost.
Horst Oertel, the owner of the farm in real life, appears briefly in the film as Walt's dad. However, since Horst has a strong German accent, his voice was replaced with an American voice.