First Blood is the first film in the Rambo franchise, released in 1982.The film deals with Rambo struggling to overcome the trauma he experienced during the Vietnam War. After a mini-war with the entire police station of a small Washington State town, Rambo confronts the sheriff at the station and is about to kill him when Rambo's former commanding officer, Colonel Trautman, tells him that it's over. Rambo replies with "Nothing is over!" and has an emotional breakdown where he tells Trautman about the protesters at the airport, how honor and loyalty mean nothing in the real world, and how his friend Joey was killed by a shoe-shining boy in a suicide attack. With nothing left to live for, Rambo decides to turn himself in to the authorities.
This film provides examples of:
Adaptational Heroism: Perhaps more like "adaptational sympathy", but Rambo was a somewhat darker character in the book. The novel puts more emphasis on the fact that the whole situation mostly happens because of Rambo's own pride, and Teasle actually gives him several chances to leave the town peacefully, as opposed to the movie where he takes him in after coming back once. Rambo's actions also seem more like vengeance, whereas in the movie they seem more like self-defense.
Adaptational Villainy: While Teasle was still a bit of a jerk in the novel, he was also a far more complex character. The novel goes into great detail on his motives, his relationships with his family and other members of the town, and acknowledges several similarities between him and John. He arguably comes off as more sympathetic than Rambo. The film makes him into a one-dimensional asshole who the audience has no trouble rooting against.
The other cops count as well, most particularly Galt. In the novel, they were, while not the nicest people around, still very sympathetic characters. In the film, the cops, with the exception of Mitch, are all insufferably unlikable douchebags.
Artistic License - Gun Safety: In the first film, John Rambo could've just as easily sat back and let the sheriff and his deputies kill each other in friendly fire accidents (fingers on triggers, sweeping muzzles through heads and chests, etc.)
Asshole Victim: Nobody cried when Galt fell out of the helicopter to his death.
Sheriff Teasle: What would possess God in Heaven to make a man like Rambo?
Trautman: God didn't make Rambo. I made him!
Blatant Lies: "Dammit, Dave, you think this kid just waltzed into town, announced he was a Medal Of Honor winner, and then I just leaned on him for the hell of it? I tried to do him a favor." That's kind of exactly what Sheriff Teasle did.
There's also the claim that he "treated him (Rambo) like one of my neighbor's kids." Apparently he's in the habit of arresting kids for vagrancy and hitting them with a fire hose.
Bloodier and Gorier: The first movie inverts this from the book. In the novel, Rambo kills at least a dozen people. In the movie he kills three people at most - one guy who falls out of a helicopter when Rambo throws a rock at him in self-defense and two cops who he ran off the road (And who quite possibly survived).
Book Ends: The first dialogue in the film has Delmar Barry's widow telling Rambo how Barry died. The last dialogue in the film has Rambo telling Trautman how Joe Danforth died.
Broken Aesop: First Blood - two hours illustrating and condemning the dehumanization of soldiers. The sequels - two hours of gleeful carnage by a One-Man Army.
Could Have Avoided This Plot: All Rambo wanted was to buy lunch before leaving town, but Teasle apparently decided that it was a crime for transients to patronize the local restaurants. See the Film subpage of Disproportionate Retribution for the extent of the destruction such pride cameth before. In the original novel, this was averted as the sheriff was willing to let Rambo buy some food in town - so long as he ordered it to go.
Did I Mention It's Christmas?: Christmas decorations are visible throughout the first movie, though nobody ever actually makes mention of the holiday.
Supposedly, the Christmas decorations were already up when they began shooting, and they left them both for the ironic quality and to worldlessly remind the viewer that Rambo is on the lam in a wifebeater and jeans during a very cold time of the year.
Disproportionate Retribution: As Teasle should have remembered, pride cometh before destruction, and a haughty spirit before a fall. His pride ended up refusing to let a Green Beret and Medal of Honor recipient eat within his city limits, and what happened afterwards more than demonstrates how much of a bad idea fucking with a Green Beret is.
Everyone Has Standards: Mitch is horrified when Art Galt strikes Rambo before the cops start to clean him up. "Galt, what the fuck was that!?"
From a Certain Point of View: Quoth Trautman: "You did everything to make this private war happen." Except for Rambo being the innocent victim when Teasle chose to harass him, arrest him on trumped up charges, before subjecting to cruel mistreatment at the hands of his fellow officers. All Rambo did was deliberately head back into town to spite Teasle for kicking him out, as well as exercise his right to remain silent when refusing to answer any questions.
Jaywalking Will Ruin Your Life: Invoked in First Blood. Rambo gets picked up by the police for 'Vagrancy', which leads to them messing with him and dredging up his Vietnam-war trauma, which leads to rapidly escalating troubles, which leads to a dead cop and, eventually, Rambo working a prison-quarry. Towards the end of the movie, during the police's Hope Spot when they think they've managed to kill him, Rambo's old general has this to say:
Trautman: Vagrancy, wasn't it? That's gonna look real good on his grave stone in Arlington: Here lies John Rambo, winner of the Congressional Medal of Honor, survivor of countless incursions behind enemy lines. Killed for vagrancy in Jerkwater, USA.
Mugging the Monster: The National Guardsmen (who are just average Joes who never expected to be called into service in their quiet town) fire wildly at Rambo's general direction while chasing him down, hooting and hollering like 19th century cowboys running down slaves... Until he returns fire, nearly hitting every single one of them, scaring them into cover. They're so terrified that they refuse to even peek out of cover.
Only Sane Man: Mitch, the young red-haired cop in First Blood, is the only one to express dismay when Galt starts messing with Rambo. He's the lowest ranking officer, though, so no one listens to him. For his part, he does get off lighter than the rest of the cops, as Rambo disables Mitch by simply stabbing him in a non-vital area (the ass) that's mostly healed by the next time we see him.
Revised Ending: The ending of First Blood was changed not because they were hoping for sequels, it was changed because they felt the film was bleak enough as it was. Apparently, the original author said he was okay with the change. Said original ending can be seen in a flashback in part 4. Trautman shoots Rambo in the gut on his urging. The original ending was played after a 2008 theatrical reissue, following the closing credits and a textual introduction.
Spared by the Adaptation: The originally filmed ending to First Blood was much closer to the novel by David Morrell, which had John Rambo forcing Trautman to kill him. However, due to Rambo's more sympathetic portrayal in the film, a new ending was filmed which had Rambo being arrested instead, making the sequels possible. Due to the relative obscurity of the novel, not many are aware that Rambo was supposed to die in the first film.
Teasle was also killed in the book, but spared in the film. In fact all the other cops except Galt all apply.