In The 5,000 Fingers of Dr. T , Bart goes to quite a bit of trouble to avoid waking Dr. T when he goes to break into the vault to steal some money...and then Bart leaves an IOU with his name for the missing cash. This winds up having nothing to do with him setting off the alarms and getting caught.
In An Affair to Remember, Terry refuses to let Ken pay for her to get better and be able to walk again because she thinks Nickie wouldn't approve, she knows Nickie can't afford it, and she thinks it would be ungrateful of her to let Ken give her back her mobility and then go marry someone else.
When Ellen Ripley of Aliens makes a promise, crosses her heart and hopes to die, you can bet your cocooned hide that no hive of monsters, snarling Alien Queen or imminent thermo-nuclear explosion will stop her from saving your life.
In Batman Begins, when Bruce Wayne realizes Ra's Al Ghul's ninja clan is a den of insanely destructive fanaticism and refuses to help them inflict such harm on the innocent. When Ducard learns about Wayne's opinion, he dismisses it and Wayne has the perfect response to illustrate his honor.
Henry Ducard: Your compassion is a weakness your enemies will not share. Bruce Wayne: That's why it's so important. It separates us from them.
Furthermore, Wayne also vows to fight evil his way. Even though he is in this den of villainy, surrounded and outnumbered 100-1, he doesn't hesitate for an instant to start his war on crime on the clan.
Wayne takes this to even greater extremes in the 2008 sequel The Dark Knight where he refuses to kill the Joker despite how much easier it would make his life and how much safer it would make Gotham, just to prove that the Joker can't corrupt him.
The Beast of War (1988). The Pashtun rebels spare the life of the protagonist (a Soviet tank driver) when he appeals to their traditional code of Pashtunwali, which requires even an enemy to be given sanctuary if he asks. Though some of the rebels argue that the rules shouldn't apply to Dirty Communists who've learnt a single word of their language (nanawatai - sanctuary), the fact that he'd been left for dead by his comrades (and is willing to repair an RPG in order to blow them up in payback) is a significant factor in his defence.
Broken Arrow: Rather than forcing Vic Deakin (John Travolta), who is out of bullets, to disarm a nuke there and then, Riley Hale (Christian Slater) drops his shotgun and accepts his former friend's challenge to one final fistfight.
Con Air: Cameron Poe (played by Nicolas Cage), one of only two decent human beings trapped on a prison transport aircraft populated by murderers, rapists and "every creep and freak in the universe", was a free man on parole who could have left the plane at any time to go back to his wife and daughter (who had never met him). Yet, the former Army Ranger in him would not allow him to "leave a fallen man behind," hence Poe gladly traded his freedom to save the life of his diabetic friend and the sole female guard eyed by the plane's worst rapist, "Johnny 23".
In Warren Beatty's Dick Tracy, Tracy is kidnapped and taken to his girlfriend's apartment building's boiler room where Big Boy Caprice tries to bribe him. Although the smart thing for Tracy would be to pretend to accept the money and then turn it in to the Police Department as soon as he's let go, Tracy decides to throw it back in Caprice's face on principle. The Kid is watching all of this in hiding, waiting for an opportunity to help, and is really impressed at the detective's fearless honor, but there is no way Tracy could have known he had an audience.
Excalibur: Queen Guinevere has been accused of treason by adultery with Sir Lancelot, but not one person will champion her in Trial By Battle against Sir Gawain ... except the unarmored, untrained page Percival who appears to be operating either under the simple principle that the Queen must be championed, or The Dulcinea Effect. King Arthurknights him for this purpose ... although the battle is averted by the arrival of Sir Lancelot to take his place.
Come to think of it, King Arthur refusing to champion his own wife against the accusation — on the basis he is king and must be her judge in this — is probably a potent illustration of Honor Before Reason.
There's a similar plot and illustration of this trope in the film First Knight. After catching Lancelot and Guinevere in an embrace (ironically, she had been completely faithful to Arthur and was merely giving Lancelot a good-bye kiss), Arthur bluntly declares, "As a man, I may forgive. As a king. . .", then declares that two will be tried for treason, in public, lest the people think that he is showing favoritism or leniency that he would never have extended to anyone else.
The Mangalores in The Fifth Element live this trope to the core, and it's used against them. When they have barricaded themselves in a room and demand to negotiate, Korben Dallas walks in and shoots the leader in the head, as Mangalores refuse to fight without a leader. This results in one of the mooks complaining, "No fair!", rather than shooting Dallas when they outnumber him five to one.
Gene Autry, famous Singing Cowboy and only celebrity to have five stars on the Hollywood Walk of Fame, is known for having created the "Cowboy Code", a set of rules for cowboy characters in family friendly westerns — which is to say almost every character he ever played — to live by. The first of which falls straight into this trope; "Never shoot first, hit a smaller man, or take unfair advantage."
Given what the Basterds tend to do to survivors of their raids (let's just say they leave them an unwanted memento on them to ensure that they are identified as being former Nazis.), Rachtman was probably lucky.
In Ip Man 2, Master Hung keeps fighting in spite of his injuries because he will not willingly concede to the British. The Twister fatally wounds him for it.
While O-Ren Ishii of Kill Bill is far from a good person, what with making her living as head of the Japanese underworld, she fights the Bride honorably, refusing to do the sensible thing and finish her off while she is on the ground. Honor doesn't really pay off against a Roaring Rampage of Revenge.
Earlier (or later), The Bride had the perfect opportunity to finish off Vernita Greene, but could not do the deed with Vernita's daughter present.
She even doesn't kill the daughter (a living witness) and apologizes for doing the killing in front of her. She tells the daughter that, if and when she needs to avenge her mother, The Bride will be waiting.
Toward the end of Kingdom of Heaven, King Baldwin IV offers Balian his sister Sybilla's hand in marriage. Sybilla is already married to Guy de Lusignan, but Baldwin IV offers to have Guy executed to allow the marriage to occur. It seems like a no-brainer, as it would allow Balian to ascend to the throne of Jerusalem, it would allow him to marry the woman he genuinely loves, and it would allow Balian to have a dangerous political rival eliminated. Balian, however, refuses, his piety not allowing him to have any part in Guy's death. Guy is allowed to live, and after Baldwin's death, ascends to the throne of Jerusalem, immediately inciting a war that allows Saladin's troops to overrun and capture Jerusalem. Had Balian accepted Baldwin's offer, Jerusalem would've remained in Crusader hands.
Balian realized long before anyone else did, that Jerusalem in Saladin's hands was not a bad thing at all, and in fact gives a passionate speech at the end of the movie not for the Crusaders to hold Jerusalem to their deaths, but in fact to lay down their arms and surrender for the glory of God. So he actually subverts the trope later.
In The Last Samurai, the samurai refuse to use firearms and technology as they considered them "dishonorable." But in real life, the samurai were more than willing to use firearms.
In Lord of War, agent Valentine will never break the law in order to arrest or stop Yuri Orlov.
Interpol agent: Let me make him disappear Mr. Valentine. Around here, people disappear all the time. Agent Valentine: I can't do that. Interpol agent:Look where we are. Who will know? Agent Valentine:We will.
The title character in the cult western Major Dundee, Maj. Charles Amos Dundee (played by Charlton Heston) has a Confederate soldier killed for desertion, despite appeals for mercy, as is military law, despite being in the middle of nowhere and needing every man he can get in order to eliminate an Apache tribe on the war path. This ultimately proves to be a mistake as it causes even more tension between his Union soldiers and the Confederates, just when they were starting to get along too.
In Master of the World (based off of the Jules Verne novel), Phillip Evans exemplifies the more unpleasant end of this trope. He is obsessed with being an honorable and courageous gentleman, and doesn't understand why John Strock doesn't openly defy Robur. He considers Strock a coward at best, and collaborating with Robur at worst, and talks down to him all the time. Strock attempts to explain that if he openly defied Robur, who has dozens of armed Mooks and what amounts to a flying battleship at his disposal, he'd be very dead very quickly, and intends to stop Robur behind his back while only seeming compliant. Evans doesn't get it, and in fact this explanation makes him think even less of Strock, as he declares that Strock's subterfuge is dishonorable.
In Pinocchio, when Pinocchio is led astray by Honest John and Gideon, Jiminy thinks about running over to tell Gepetto about it, but then decides to go after Pinocchio himself because "that would be snitching".
William Turner of the Pirates of the Caribbean trilogy is another suicidally selfless example of this trope. For an example, see the "You can't... I can," scene in the first movie. Even the initially selfish Captain Jack Sparrow seems to be infected by his idealism, and eventually obeys this trope as well. In Sparrow's case, though, he obeys the trope explicitly because he knows that it's the last thing people expect from him.
Norrington: You actually were telling the truth. Capt. Sparrow: I do that quite a lot, yet people are always surprised.
Norrington in Curse of the Black Pearl:
Jack: Think about it — The Black Pearl? The last real pirate threat in the Caribbean, mate. How can you pass that up? Norrington: By remembering that I serve others, Mister Sparrow, not only myself.
Those may have been his sentiments, but Norrington's actions were mostly reasonable. Barring the whole 'underestimating peculiar pirates when he really should have known better' part—that could possibly be stress combined with, well, Jack Sparrow.
Every incarnation of the Predator lives by this trope. They will not kill anyone who is unarmed, ill, pregnant, or any other factor that would make them a viable non-combatant. They will also respect the wishes of their enemy if they desire to face off in a melee duel, as seen in the 2010 film Predators. They also may respect anyone who manages to kill one of their own, as seen in the second film. But sometimes, usually when provoked, they just throw honor out the window and use every weapon at their disposal to obliterate the enemy regardless of fairness.
The Purge: Deconstructed Trope. One of the Sandin kids lets a stranger into their house because he really looks like he is in trouble. As a result of doing the morally right thing, horror ensues.
The shining examples in Reservoir Dogs. Honor may just be a Tarantino thing. In the most prominent example in the film Mr. Orange tells Mr. White he is in fact a cop, despite knowing that he would be killed. He waited until after the police showed up. He actually managed to preserve his honor by performing his duty as a cop and was suicidally sincere with a man who just saved his life under false pretenses. If that isn't honor, I don't know what is.
Captain Miller's decision to let the German sniper live in Saving Private Ryan. Dumbass move with a capital D. But later, when Miller explains why he chooses Compassion Over Reason, you "almost" understand why he did it.
In the film version of The Sound of Music, after the Nazi takeover, Uncle Max says, "Well, the Anschluss happened peacefully, let's at least be grateful about that." Captain von Trapp replies, "Grateful?!". As he was brought up as a part of Europe's old warrior-caste he probably took the fact that Austria submitted peacefully as a personal insult.
Captain Kirk and his crew decide that court-martial is a better alternative than not trying to rescue their friend in Star Trek III: The Search for Spock. This wouldn't necessarily be an example of the trope if they had just gone and never come back, but in the next film they all willingly go back to face that court-martial. They then save the Earth on upon their return, so the actual court-martial involves nothing more serious than Kirk being demoted to Captain and handed a shiny new Enterprise.
Luke Skywalker's unconditional love and faith in the humanity of Darth Vader, seen as at best stupid and at worst suicidal by the rest of the galaxy, was what saved his father and the Star Wars galaxy.
Simultaneously giving us the second greatest Crowning Moment of Awesome in the franchise, and setting his father up to give us the greatest one.
Luke actually throws away his lightsaber so that he is defenseless against being tortured to death by Palpatine, rather than kill Vader and go to the dark side.
Then again, the Emperor was very explicit about his intended end state of Luke falling to the dark side.
Except, at least the part about Vader, it was hardly stupid — for a talented and trained Force Sensitive, it is far more reasonable to trust your feelings and instincts. Luke states on more than one occasion that he can sense the good in Vader, and there's little reason to doubt this is true.
And you don't have to be force-sensitive at all to see ahead of time that Luke's faith wasn't completely misplaced. "It is... too late for me, son" isn't a line you'd expect to hear out of someone who is completely heartless or beyond saving.
The Sword, a short film by Pointy Stick Productions, appears to be built entirely around this idea. It features a boy with hundreds of opportunities to exploit flaws in the strategies of the Muslim invaders outside his castle wall, and an able-bodied monk in the castle that, with the boy's help, could at least match the invaders' fighting skills and shut the gate long before help could arrivefor either side. This is made worse when the boy's father thinks it okay to go off and fight in the Crusades; but doesn't think it important to teach anyone how to practically defend a castle, nor work as a team. The fact that the castle is so oblivious how to defend itself save for its gate and that the villains in the forest, with all the accessible wood, don't think to build a flaming battering ram to take down that gate illustrates that the short film's producers really weren't all that concerned with historical realism. The one saving grace is perhaps that the monk successfully averts some films' certain beliefs about monks.
In Tangled, Rapunzel promises to return Flynn's satchel with the stolen tiara if he agrees to escort her to the palace to see the flying lanterns, stating, "When I make a promise, I never break it." Later, after Gothel stabs Flynn in the back, Rapunzel vows that she would never stop trying to escape her. She then tells her that she will not fight her or try to escape if Gothel lets her save Flynn's life with her magic hair. The trope is then averted when Flynn shears her hair off with a mirror shard, removing its healing properties at the risk of his own life.
The most noble live-action example would have to be Indiana Jones in Temple of Doom, who could have escaped with fortune and glory, instead got captured to save a helpless little boy from being whipped to death. Not the smartest of moves, yes; but any illusions of him being a heartless and cynical mercenary disappears at this point, and we cheer for him all the way as he saves all of the children and defeats the evil of Kali-Ma.
John Connor of Terminator 2: Judgment Day is another admirable example of this trope: he stops Sarah from killing Dyson even if it meant preventing Judgment Day, and his idealism allowed a war for humanity's future to be waged and wonwithout murdering a single innocent human being.
Well, at least until the movie that followed. And the movie that followed that where-in it is revealed they didn't prevent Judgment Day, but delayed it, along with the deployment of T-600 and other sophisticated terminators.
Troy: Hector personally goes out to fight the invincible Achilles to allow the man vengeance for killing his cousin, despite knowing that Achilles can kill him easily, the cousin was dressed up like Achilles and charged headfirst into battle, and they had an squad of archers on the wall who could have put down Achilles fairly easily.
Once Upon a Time in the West: The villain, Frank, has a chance to ride away safely after killing his boss, Morton. Instead he comes back to face his nemesis, the man with the harmonica.
Frank: "Morton once told me I could never be like him. Now I understand why. Wouldn't have bothered him, knowing you were around somewhere alive." Harmonica: "So, you found out you're not a businessman after all." Frank: "Just a man."
In Django Unchained, Doctor Schultz has been repeatedly shown to be an honorable, but prideful, man. Toward the end of the film, the only thing Schultz has to do to allow himself, Django, and Broomhilda to leave the plantation alive is shake the reprehensible Calvin Candie's hand. Ultimately, Schultz cannot bring himself to degrade himself by shaking this monster's hand, and fatally shoots Candie, knowing full well it will ensure his own death and endanger Django and Broomhilda. He even apologizes before he's blown away.
In Tenacious D in The Pick of Destiny, turns out that even the Devil must abide by the Demon Code, meaning he simply cannot refuse anyone who declares a rock-off challenge. Keep in mind, he presumably wrote this code in the first place!