A character who makes The Promise, must follow the Prime Directive, or is otherwise The Fettered who will be forced to break it... repeatedly. Usually they'll face a veritable parade of situations that force them to choose whether To Be Lawful or Good, Godzilla Thresholds that require heartless necessity, and otherwise constantly force them to compromise their word and/or morals to win, do what's right, survive and/or protect the people they love.
This may take a variety of forms, for example the Actual Pacifist will be turned into a Reluctant Warrior who has to kill to protect the innocent. The Captain will have the completion of their orders and the lives of Innocent Bystanders as mutually exclusive. The Watcher will be compelled off his True Neutral vague fence sitting into taking a side. On a smaller scale, any parent or lover promising to "spend time" with a loved one will be called away to duty... not that the loved one ever understands or puts up with for long.
Expect The Fettered and The Cape with a Heroic Vow to be especially prone to suffer this, though the Noble Demon may be an infrequent target. See also Oddly Common Rarity. If the story has Magically Binding Contracts involved, they'll be as binding as warm swiss cheese. Unless it isn't. If the vow is only broken once or twice, then it's Batman Grabs a Gun.
- Roger Smith of The Big O often says that violence is a last resort in his negotiations... but then, we would never get to see him kick ass in his Humongous Mecha if negotiations didn't break down on a regular basis, now would we?
- In Bakuman。, Mashiro and Azuki promise to never see each other until their dreams come true, but this is broken on a few occasions, such as when Mashiro is hospitalized or when Azuki receives an offer to be the female lead in Natural+, resulting in Mashiro having to come to see her, inspiring her to act on her desire to turn it down. They lampshade how often they've seen each other in spite of their promise, but note that the cases have been emergencies. Azuki decides that they will kiss the next time they see each other so that they will commit to their promise. The next time they meet is after Azuki becomes the female lead for Mashiro and Takagi's anime.
- This is the reason Byakuya has become a Knight Templar by the start of Bleach. As a noble, he is expected to embody the rules and traditions of Soul Society, but he broke these rules twice; once to marry a commoner he'd fallen in love with and, when she died, he swore on her deathbed he'd find, adopt, and protect her little sister (Rukia), breaking the law a second time. He swore that this would be the absolute last time, and that he'd obey the laws no matter what from here on. So, later when Rukia was branded a criminal to be executed for her crimes, he obeyed the law, captured her, and prevented her friends from rescuing her. After being defeated by Ichigo, however, Ichigo convinces him that there's nothing wrong with breaking an unjust law, as shown in the page quote of To Be Lawful or Good. Byakuya has also since learned to abuse loopholes when subverting orders that he personally disapproves of but which aren't actually unjust; sometimes it's possible to not personally break any rules but at the same time facilitate someone else breaking them. Especially when his superiors didn't think to specifically forbid him from doing this.
- Dragon Shiryu in Saint Seiya has several of these with direct orders by his Old Master to never use such or such Dangerous Forbidden Technique. Instances include "being forbidden from using Rozan Shōryūha when weakened or Overdrawn at the Blood Bank" (which he had to break against Black Dragon to take him down in a desperate situation ; he only survived by virtue of HeelFace Turn from Black Dragon impressed by his friendship), "being forbidden from using Rozan Kōryūha" (which he breaks against Capricorn Shura, but admittedly he was on his last leg and a Taking You with Me Heroic Sacrifice was his only way out ; he only survived by virtue of HeelFace Turn from Shura). The reason why this feels like this trope is because every time he does it, he vocally points out he is breaking his promise with his Old Master, for the greater good, but in reality this is more like a sign that the Godzilla Threshold has been broken and it's time to bring out the big guns.
- In the Marvel Universe the Watcher repeatedly violated his oath of non-intervention. Sometimes he does so outright (as in his very first appearance), other times he finds ways to "technically" obey the oath while still somehow helping Earth's heroes. For example, he likes to make his presence known to Earth's heroes (not difficult given his immense size) whenever observing a major event, even though he can watch events just fine from light-years away. Therefore, he doesn't even have to utter a word to make it clear that something of great importance is about to happen. Original Sin #0 reveals that when the rest of his race vowed never to interfere with other species again, he protested the decision and argued that they could learn from their mistakes and do better next time. He has few qualms about bending or even breaking the oath because he never followed the oath in spirit.
- In Star Wars, the one rule of the Sith is the Rule of Two. There can only be two Sith, a master and an apprentice. No more, no less. However, given the treacherous and rule-breaking nature of the Sith, this rule is often bent, twisted, or otherwise ignored. Some masters and apprentices trained Dark Side Assassins as a way to technically not violate the Rule of Two. Other Sith apprentices have straight up trained secret apprentices with the goal to kill their current master. Even the originator of the Rule broke it by training two apprentices, suggesting that the Rule wasn't actually meant to be adhered to.
- In Dragon Bones it is mentioned that oaths of allegiance are considered cheap and no one takes them seriously, least of all the high king Jakoven. When an elderly nobleman starts a plea to the king by saying that he has sworn by his life-blood to be loyal to the king, every decent person present pities him for being so naive as to believe that the king would actually honour his promises. It's all about power, if you have power, you can break your promises all you like. Or that's what Jakoven thinks ... until the nobles have had enough and start a revolution.
- And then there is the whole Hurog family, whose holy duty is to protect dragons. They have been doing a pretty bad job for a very, very, very long time. Ward, the protagonist, is the first one to actually do some dragon-protecting. (One of his ancestors killed a dragon, and the ones that came after that liked the title, but never made a real effort to find out what happened to the dragons.
- A Song of Ice and Fire:
- Used frequently, even to the point of Running Gag extremes. Many major groups in the setting take vows of chastity (Maesters of the Citadel, Black Brothers of the Night's Watch, brothers of the Kingsguard, etc.) and few of them take the vow even a little bit seriously. (The Night's Watch gets by on a bit of Loophole Abuse: their vow is to "take no wife and father no children," and given the ubiquity of moon tea and tansy in the setting, as long as they stick to whores who know their business, there's relatively little chance of that.)
- Part of the reason for Jaime "Kingslayer" Lannister's Card-Carrying Villain-level openness about his lack of honour is because of his disgust with this trope; when he killed the Mad King he was vilified for his treachery despite solemn oaths of loyalty and moral behaviour getting violated left and right in the Crapsack World of Westeros. He is particularly resentful of the fact that nobody actually disputes that he did the realm a favour, yet still condemn him for doing so, and whenever he tries to draw attention to the endless array of mutually contradictory oaths, his "honourable" opponents continue to despise him.
- The Hound's absolute refusal to be a knight is because he considers all their vows to be this; his own brother is a knight and is one of the most monstrous characters in a series full of reprehensible individuals, and the Hound prefers to simply be "a sword and a horse" and not bother with the oaths and ladies' favours that are just "silk ribbons" tied around the sword to make it prettier, but no less lethal.
- In the Warrior Cats series, the Warrior Code (which forbids inter-Clan relationships, has rules about territory, lists prerequisites to achieve certain ranks, and lists other rules about what they're allowed and not allowed to do) is broken quite often.
- Goes to the point of deconstruction with Hollyleaf, who is so obsessed with the code that she breaks down when she realizes that she's the product of a forbidden inter-Clan relationship.
- Death of the Discworld is bound by The Duty to impartially collect souls, and has apparently done so offscreen very diligently for thousands of years, but in the books themselves he has a breakdown and runs off more than once, and also spares people's lives repeatedly because of curiosity or pity or personal relations or because Granny Weatherwax asks him to. (He also killed someone for no reason in the first book, but that was before his character was really decided.)
- In Harry Potter, the Unforgivable Curses are so bad that using them on a human gets a life sentence in Azkaban. In the fifth book, Harry briefly uses the Cruciatus Curse on Bellatrix after she kills Sirius. Okay, it was an extreme situation...and then he tries to use it on Snape in the next book. Um, don't make a habit of this, Harry. Then, in the final book, he uses the Imperius Curse to avoid being caught by a villain. Well, at least in that case it was life or death... And then he uses the Cruciatus again when a bad guy spits on McGonagall. And she praises him for it!
- Averted with the Unbreakable Vow. If you break it you die, with no Loophole Abuse allowed.
- Animorphs' Ellimist, like Uatu above, does not interfere with other species. Except when he does all the time, but claims that he's not interfering. It's later clarified that he can only interfere through agreements with his Evil Counterpart, Crayak (which inevitably means allowing Crayak to interfere for evil elsewhere), so he pulls off as much Loophole Abuse as possible.
- Game of Thrones:
- Vows of chastity are integral to orders such as the Night's Watch, Kingsguard, and Maesters of the Citadel, but Loophole Abuse is common since the Exact Words often only forbid wives and children. The nearest town to Castle Black even has a thriving brothel catering to black brothers of the Night's Watch.
- A major reason for Jaime Lannister's openness about his lack of honour is his disgust with being vilified as The Oathbreaker for killing the Mad King despite solemn oaths of loyalty and moral behaviour being violated on all sides.
- The Hound consistently refuses knighthood because he considers their vows to be this. Thoroughly reprehensible men like his brother Gregor are knights, so in the Hound's opinion knights are just killers pretending not to be. He prefers to forgo the pretense altogether.
- Star Trek franchise:
Admiral Satie: Would it surprise you to learn that you have violated the Prime Directive a total of nine times since you took command of the Enterprise? I must say, Captain, it surprised the hell out of me.
- Star Trek: The Original Series. Captain Kirk's willingness to break the Prime Directive whenever he needed to save the Enterprise and/or a "stagnant" culture is well known. He was also a hypocrite on the issue, condemning Captain Tracy in "The Omega Glory" for doing something he had done before and would do again. Note that Mr. Spock was also guilty for not arresting Kirk each time he did it (as noted in "The Omega Glory", any Starfleet officer who doesn't take action is as guilty as the person committing the offense).
- In an episode of Star Trek: Enterprise, Archer imagines that maybe some day, there'll be some kind of rule or directive to save captains from having to make such judgment calls. Of course, the judgement call in question was his decision to withhold a cure from a dying race, based on Phlox's assertion that nature "selected" them to die so another race could thrive. A Prime Directive would have at least given Archer a rule he could hide behind to justify committing genocide.
- Oddly enough, TNG asserted that Kirk had violated the Prime Directive in circumstances TOS clearly established was not a Prime Directive violation by the interpretation held by Starfleet at the time (they would have been in TNG, but Kirk can hardly be faulted for not knowing about regulation changes decades before they happen).
- Star Trek: The Next Generation episode "The Drumhead" reveals that even Picard, by far the most diplomatic Captain, nonetheless had nine separate violations on his record. This was a late season 4 episode, meaning he had dozens more episodes and four movies in which to rack up more violations.
- The Mortal Kombat series has one rule enforced by the Elder Gods: You aren't allowed to invade a realm without defeating it in ten consecutive Mortal Kombat tournaments. As early as II, this rule begins to collapse as Shao Kahn plots to either loophole around or just plain ignore the system in favor of a forcible invasion.
- Fate/Unlimited Blade Works focuses on Shirou coming face to face with the reality that his ambition to save everyone is impossible, and his failures in pursuing it may ultimately destroy him. Despite knowing it is impossible, Shirou resolves to do his best to uphold the ideal regardless.
- Discussed in the Writing Excuses episode on Comedy. The podcast says that if an author puts a character in a situation in which violating their principles would be easy, and adhering to them would be painful, that's a good and fairly easy way to create humor or drama, depending on what the author is going for. However, an author can't keep forcing a character to break their principles, or else they'll stop being principles.
- In the fifth Season of Noob, one of the players gets a job that amounts to making a Non-Player Character that is an important part of the game's story be controlled by a real person rather than artificial intelligence. He promises his new boss to never break character while on the job, but between getting used to the character's World Boss statistics, making players that know him aware of the situation and other incidents, there are only one or two scenes showing him not breaking character.
- Words like "'til death do you part" and "for as long as you both shall live" are very common in wedding vows. The divorce rate approaches or exceeds 50% in many Western countries (although it's inflated somewhat by serial divorcers). The infidelity rate is harder to measure exactly, but is also quite high. Do the math.
- Some Catholic bishops release priests from their duties and vows of celibacy, because they've fallen in love and want to get married. It's a relatively long process because of the seriousness of the change and the awareness that often such feelings pass and fade as above, but there is a process in place.
- Averted by the Quakers (a religious group, also called "The society of friends"), who take the Bible's word on not swearing oaths seriously. Thus, they manage to stick to the principles that are in the Bible, the ones of their own religious society (there are several cases in history where Quakers got in trouble for refusing to swear oaths), and don't get into the predicament of having to break vows, as they never made them in the first place.
- A quote attributed to Napoleon Bonaparte is "the best way to keep one's word is not to give it."