In the scene where Dustin Hoffman's character first enters the local pub, Sam Peckinpah was unhappy with the other actors' reaction to this stranger entering their world. Eventually, he decided to do one take where Hoffman entered the scene without his trousers on. He got his reaction, and these are the shots shown in the final film.
In order to express a sick enjoyment in the scene where Dustin Hoffman beats the man on the floor to death, he requested that there would be coconuts there for him to smash. In one shot you can actually see a bit of coconut flying off, which Sam Peckinpah passed off as brain matter.
When Reverend Barney Hood and his wife visit David and Amy Sumner to invite them to a church social, Barney and David discuss science and religion. David recites a quotation, "There's never been a kingdom given to so much bloodshed as that of Christ." Barney recognizes the quotation to be from Montesquieu. Montesquieu was a French social commentator who lived from 1689 to 1755. He is sometimes credited with the concept of separation of powers that was incorporated into the U.S. constitution.
The future of the film was put in jeopardy when director Sam Peckinpah caught pneumonia after an all-night drinking session with Ken Hutchison in the sea at Land's End. Having recuperated at a clinic in London, Peckinpah was only reinstated after promising that he would remain sober.
The title comes from the Chinese philosopher Lao-tzu, who wrote, "Heaven and earth are not humane, and regard the people as straw dogs." Straw dogs were used as ceremonial objects for religious sacrifices in ancient China.
Henry Niles' limp was not part of the script. David Warner had broken his leg before production but was able to walk with a cane by the time principal photography started. Because he had broken his foot before shooting (hence the limp), he was considered uninsurable and thus is uncredited.
T.P. McKenna, who plays Major John Scott, has his arm in a sling. This wasn't written in the script - McKenna had broken it while having a wild party with a couple of prostitutes, arranged by director Sam Peckinpah.
Tom Hedden's family were originally given roles in the film, but they were either cut or never filmed. June Brown was cast as Hedden's wife, together with Chloe Franks as their daughter Emma, and a scene was scripted featuring both in their home doing laundry with Susan George. However, although the scene was included, it was never filmed. Michael Mundell was originally cast as Cawsey the rat-catcher but was later switched to the role of Bertie Hedden in a scene featuring the village children. However, this entire scripted role was also never filmed because the scene was canceled due to time and budget constraints.
The opening pub scene mentions "thirty bob." This sum was, in pre-decimal money, 50% more than a pound. A pound, pre-1971, consisted of 20 shillings. Also, for modern audiences, it would be perhaps helpful to know that UK licensing laws required pubs to close every afternoon between 2.30pm and 6pm - though the precise times were variable, because of various by-laws ,in differing counties and boroughs.
When Sam Peckinpah was planning the scene in which Amy is raped twice, he would not tell Susan George how he was going to shoot the scene. Under pressure from her, he eventually told her bluntly that Amy would first be raped and then buggered. She refused to take part in Peckinpah's plans for explicit portrayal of this and threatened to resign. He eventually relented, allowing George to depict Amy's trauma by concentrating on her eyes and face, rather than her body.
In 2002, the BBFC would have passed the film with cuts to the rape scene (shots implying Susan George may be enjoying the rape) but Anchor Bay refused these cuts so the film was ultimately rejected, although it passed uncut on a subsequent submission.
The film was originally seen in work print (unfinished) form by the BBFC, which suggested minor edits to the killing of Vennor and to the second rape scene, which implied that Amy was sodomized. The edits were carried out and the completed film was passed uncut for cinema by the BBFC. Subsequent attempts to release the film on video, however, proved unsuccessful, as chief censor James Ferman suggested cuts to the rape scene (over 3 minutes) but found them difficult to carry out. Another attempt to release the film was prevented by concerns over the 1987 Hungerford massacre. After 5 attempts proved unsuccessful, an edited version of the film (removing most of the second rape) was officially submitted in March 1999 but was rejected by the BBFC as it was felt that too much emphasis had been placed on the initial 'pleasure rape' of Amy by Vennor. The film was again rejected 3 months later (in its complete form) when submitted by a different distributor, as it was considered inappropriate to pass the uncut version after recently rejecting an edited one. It was finally passed fully uncut for DVD in September 2002.