A 1970 novel by James Dickey, adapted into a 1972 film directed by John Boorman and starring Jon Voight, Burt Reynolds, Ned Beatty, and Ronny Cox.A group of stuck-up Atlanta yuppies decide to go into the wild countryside of Georgia where they do a little canoeing, play a little banjo, and suddenly get brutally raped by a pair of local hicks. After one of the group kills the rapist, the four city boys must try and escape the town before the locals find out what happened. However, the dead man's accomplice ran off, and starts hunting them down like animals. The film is best known for the page quote about squealing like a pig and the "Dueling Banjos" scene. If you ever see the film you will never be able to enjoy banjos again. Or go canoeing. Or visit rural Georgia. Or, you know, sleep.
Corrupt Hick: The film would seem to be both played straight and subverted. On the one hand, the rapists themselves play this deadly straight. On the other, we never see the rapists again and while the rest of the hillbilly town is set up to be creepy and/or evil, they never really do anything, good or bad. There's one police officer who mentions that his brother-in-law went missing recently and is suspicious of the protagonists, but the sheriff rightly says they don't have sufficient evidence to arrest them and instead advises that they leave the town and never return. Especially subverted in the case of the mentally challenged banjo player (probably the most famous character in the film), whose banjo playing provides a creepy soundtrack but who is otherwise benevolent.
Crazy Survivalist: Lewis plays around with this. He adores doing the whole Mountain Man thing, scorns people who he thinks rely on or are products of civilization, and believes that at some point society will break down and we'll all have to rely on our wilderness survival skills — Ed suggests that Lewis actually can't wait for that to happen. At the same time, it's implied that Lewis isn't actually as good a survivalist as he thinks he is, and he takes everyone canoeing down that river without finding out if it was safe first, and even after a local warned him it was extremely dangerous. This comes back to bite him in the ass big time when the canoes hit some major rapids, tossing them all out and breaking his leg.
In the gym episode of Rocko's Modern Life, Rocko gets on a rowing machine and accidentally sets the difficulty level to " Deliverance". The computer tells him "We gonna make you squeal, piggy!" (Luckily, in this case it involves making a pig laugh by tickling it with a feather).
Plus, he says "You got a purdy mouth," just before he banjos the zombie.
Also referenced in Kevin and Kell where a character is arguing that the lack of hunting is not causing inbreeding of prey species... followed by someone identifying the music of the scene as Dueling Banjos.
In the Futurama episode "The Deep South", Bender hums a few notes from "Dueling Banjos" when he is first introduced to the lost city of Atlanta (no, not Atlantis, Atlanta).
In The Simpsons episode "Boy-Scoutz 'n the Hood", Bart's Junior Campers rafting group (led by Ernest Borgnine) gets lost and winds up drifting through a river in the woods; mountain men are seen in silhouette along the shoreline while the opening strains of "Dueling Banjos" play.
South Park episode "The China Problem" had a dream sequence in which George Lucas and Steven Spielberg rape Indiana Jones while telling him to squeal like a pig.
Referenced in an SUV commercial, which shows four guys excitedly setting up a campsite, until they hear banjo strings... Then it shows them piling back into the car and peeling out.
The kids' show Cow and Chicken had a scene where Chicken is paddling a canoe down a river, and a creepy hillbilly is laughing and commenting on his "Purty beak", Chicken then starts panicking and rowing away faster.
British comedy Father Ted homages the banjo duel in a completely random scene — complete with a man dancing along.
Horrible Camping Trip: Oh, come on, you big girl's blouse. It's only a bit of horrific rape! Don't ruin the trip for the rest of us.
Riddle for the Ages: The most common, or second most common question from many in the audience tends to be: was the man whom Ed shot the same one who had intended to violate him earlier? (Yes, he was.) However, the actual persistent mystery, which remains ambiguous and unexplained, is Drew's fate: was he shot, did he fall into the river accidentally, or did he choose to jump in? Director John Boorman tended to be evasive on the subject, author James Dickey felt it was murder, and Drew's actor Ronny Cox believed it was suicide. Nobody really knows and John Boorman says it's up to each viewer to decide.
Very Loosely Based on a True Story: Very, very loosely based. Writer James Hickey took a canoe trip in the Georgia woods and got lost but was actually helped by local mountain men, who were friendly. Of course that wouldn't make an interesting book...!