Ben Wheatley has stated a big reason he set the film in the 70s is so there would be no mobile phones.

Armie Hammer said that police appeared on set during the second day of shooting following calls of concern from members of the public in nearby shops having heard gun shots.

Ben Wheatley has said that one of the inspirations was an actual F.B.I. report on a Miami shootout.

While planning out the dimensions of the set, Ben Wheatley built a scale replica of the film's warehouse in Minecraft (2009).

Ben Wheatley described games such as Half-Life: Counter-Strike (2000) as a source of inspiration for the film.