Heroic Vow

""I swear with words not yet written, on gods not yet born... I will never run away again.""

- Kin, Goblins

Most protagonists are depicted as imperfect; though heroic, they aren't flawless paragons of perfection, and will have some minor shortcomings to help the audience identify with them better. SuperBob can selflessly save the world on a daily basis, but mild-mannered Bob Trope will regularly leave the refrigerator door open.

Even so, some characters have a Heroic Vow: a commitment or standard that they will not cross for whatever reason. Perhaps it's a promise to a dear one, a sense of pride, a personal Moral Event Horizon, or just because the hero is a Nice Guy. If a villain takes a Heroic Vow, it's usually because Even Evil Has Standards.

Key to the Heroic Vow is that it is a commitment the character keeps because he willingly wants to. There are no talismans or failsafes preventing the breaking of the Vow, nor are they needed -- the character's willpower and resolve are the only bonds needed.

Note that the Heroic Vow doesn't necessarily have to be spoken (or written); a hero's behavior enforced with sheer personal willpower counts. If the vow is spoken/written, it may become a Badass Creed.

Some Heroic Vows are so commonplace, they have their own tropes:
 * Celibate Hero (will not have romantic or sexual relationships)
 * Doesn't Like Guns (will not use guns)
 * Never Hurt an Innocent
 * Thou Shalt Not Kill (will not kill another person -- sometimes will not kill anything)
 * Wouldn't Hurt a Child
 * Wouldn't Hit a Girl

Often an application of Heroic Spirit, and popular with a Knight in Sour Armor. When done well, can lead to Moments of Awesome. When done poorly, can result in Honor Before Reason, Stupid Good, or Serious Business. If a hero becomes obsessed with enforcing his Heroic Vow, he may end up becoming The Fettered. If unlucky, they'll be forced to make their Vow a Frequently-Broken Unbreakable Vow when circumstances force them to break it.

A convenient Narrative Device to drive a story in a direction it wouldn't normally go. Sometimes used to deliver An Aesop on morality. If the character is forced into breaking the Heroic Vow, expect a Heroic BSOD. If his determination to keep his vow starts to slip, it can be a prelude to Jumping Off the Slippery Slope.

Compare and contrast with Empty Promise, I Gave My Word, Pinky Swear, and Exact Words. When someone has broken this vow so thoroughly they become ostracised they're The Oathbreaker. If the oath is strong enough to prevent even mind control from forcing them to break it, it's an Intrinsic Vow.

Anime & Manga
"If you ever lose your mind, don't worry. I'll destroy you myself."
 * Many heroes refrain from killing, but Rurouni Kenshin is very, very serious about the topic -- to the point of preventing other people from killing if at all possible.
 * Also in the Thou Shalt Not Kill camp, Vash from Trigun.
 * In Super Robot Wars, Kyosuke promises Lamia that he'll kill her if she loses her mind.


 * Naruto's vow to bring Sasuke back to Konoha. Arguably in the series every character has one, but Naruto's is the most important plotwise.
 * The latest arc in the story may be subverting this a bit, by showing the burden and increasing impossibility that this vow seems to entail.
 * He has not (so far) gone back on it, but he tells Sakura that it's no longer the main reason why he wants to bring Sasuke back.
 * Edward Elric from Fullmetal Alchemist made a vow to his brother to restore his body without resorting to the Philosopher's Stone, which drives him for most of the story. He also refuses to kill people but unfortunately sometimes his two vows clash.
 * Also, and similar to the Super Robot Wars example, Riza Hawkeye has promised Roy Mustang that if he ever deviates from the righteous path, she will shoot him rather than let him go against his ideals. In an odd twist, this was his idea.
 * In Mobile Suit Gundam Unicorn, Banagher gave his word to Audrey that he would protect her, and he's sticking to it, no matter what fights he gets plunged into and whether Audrey would like this or not.
 * Shinn from Gundam Seed Destiny vows to protect Stella, even if it means
 * Balsa from Serei No Moribito has vowed to save one life for everyone who died to protect her.
 * She also vowed not to kill, though that was a more recent event within the story.
 * In Eureka Seven, Renton make a personal vow that he will protect his beloved Eureka. He nearly broke his vow when he  in episode 21, but this vow eventually motivates him to go back.
 * In Eureka Seven, Renton make a personal vow that he will protect his beloved Eureka. He nearly broke his vow when he  in episode 21, but this vow eventually motivates him to go back.

Comics

 * Spider-Man has the infamous quote, "With great power comes great responsibility."
 * The Astro City story "Old Times" features Supersonic, a Flying Brick who pledged to always use an original method against each of his opponents.

Film

 * In The Princess Bride, Inigo Montoya devotes his entire life to finding the six-fingered man who killed his father.
 * Similarly, Inigo insists on a fair fight with his opponents, to the point of helping the Man in Black up the cliff and waiting for him to be rested before beginning their duel.
 * In G.I. Joe: The Rise of Cobra, Snake-Eyes takes a vow of silence
 * In Pixar's Up, Carl and Ellie Fredriksen make a vow to visit Paradise Falls... even if it takes them an entire lifetime to do so.
 * In Kung Fu Panda, Po endures everything thrown at him in his Training From Hell to become the Dragon Warrior. Noting that "a real warrior never quits," Po vows to persevere no matter what, and endures everything inflicted on him without complaint.
 * There's a Running Gag in Galaxy Quest where Sir Alexander Dane winces every time he hears or says his Catch Phrase. It becomes a Heroic Vow after
 * The Contract in The Man Who Would Be King is one of these.

Literature
"Every day. Read to Young Sam. No excuses. He'd promised himself that. No excuses. No excuses at all. Once you had a good excuse, you opened the door to bad excuses."
 * In Terry Pratchett's Thud, Sam Vimes will stop whatever he's doing and go home to read "Where's My Cow?" to his son at 6 o'-clock... even if he's halfway across town or buried underground at the time.

""Oh dear," muttered Aziraphale, not swearing with the practiced ease of one who has spent six thousand years not swearing, and who wasn't going to start now."
 * The Discworld novels also suggest that this is the only reason Granny Weatherwax doesn't become a stereotypical Wicked Witch.
 * Arguably, Aziraphale in Good Omens has one in regards to profanity.

"Rule One: Don't kill anyone, ever.
 * Sparhawk of David Eddings' Elenium, who maintains an ironclad sense of personal honor and dignity despite his own world-weary cynicism and the criminals and evils he has to deal with.
 * Gawyn Trakand from The Wheel of Time swears an oath to protect his sister to the death, even when she makes his childhood a living hell with her antics, she runs off in the middle of training twice, leaving him behind. It gets worse, yet he never waivers.
 * Two major ones from Animorphs. Firstly, the kids will never morph a sentient species without the individual's express permission. The other vow is a little more vague: The kids "fight Yeerks, but won't become them". This essentially means the kids agree to not use the same underhanded tactics Yeerks use (cold-blooded murder, ganging up on a single enemy, etc.)
 * These are a major element in C.J. Cherryh's Morgaine Cycle. They form a big part of Vanye's characterization due to his Nhi obsession with honor, and when he does something stupid to keep his honor he's generally well aware of the stupidity of what he's doing. Oaths, their making, their consequences and the attendant difficulties, anguish and so on make for some major drama.
 * In Pyrates, George van Gelder and his friends pledge to protect each other no matter what.
 * The Chronicles of Narnia: In "The Voyage of the Dawn Treader", Reepicheep pledges to find Aslan's country.
 * Also, Caspian made one at his coronation to search for the seven missing lords.
 * Morley's Code of Ethical Behavior from Burnt Empire.

Rule Two: Never blackmail, especially not for anything disgusting.

Rule Three: Never steal, ever.

Rule Four: There is no Rule Four.

Rule Five: Don't insult anyone who doesn't deserve it."

""I swear--by my life and my love of it--that I will never live for the sake of another man, nor ask another man to live for mine.""
 * John Galt's oath in Atlas Shrugged:

Live Action TV

 * Star Trek's Prime Directive: every Starship captain swears a solemn oath that he will risk his ship and crew, rather than interfere with a planet's normal development.
 * It may seem to be violated so often it is hardly a vow at all, but many of the cases are actually a case of Loophole Abuse, especially early on: the Prime Directive forbids interfering with a planet's normal or healthy development, depending on the quote in question. A captain may argue that failing to develop at all is not normal or healthy development, especially if it is not by the free choice of the members of the culture in question, and Starfleet itself originally mandated discreet interference in the most severe case of ceasing to develop, namely ceasing to exist.
 * The principle is generally expressed as a right of self-determination for any society. Even if this means that society making choices which harm or even destroy itself (like oppressive government or civil war). It is also taken much more seriously in the case of civilizations which have not yet developed interstellar travel, that's where the "normal development" part really comes into play; these civilizations have to find their own way to the stars while figuring out how best to run their society (or not). They are treated some-what like under-age minors, simply off-limits even if you might have the best of intentions. In-universe, opinions differ on whether "normal development" includes acts of nature (like the local sun going supernova or a naturally occurring disease which threatens to wipe out a sentient species who possess inadequate medical technology).
 * Mac Taylor will categorically not allow evidence fabrication or tampering within his lab.
 * Derek Reese from Terminator: The Sarah Connor Chronicles. He will stop at absolutely nothing in order to fight the coming cybernetic invasion, simply because no matter how hopeless it gets, it's not just the right thing to do... it's the only thing to do.

Tabletop Games

 * The Dungeons and Dragons Splat book, The Book of Exalted Deeds, has various vow Feats that carry advantages and disadvantages. The Vow of Poverty for instance disallows you from owning equipment, but gives you roughly 80% of your estimated wealth in bonuses).
 * In Exalted, the Charm Righteous Lion Defense causes a magically enforced version of this: one of the character's Intimacies becomes utterly inviolate, and nothing, not even Mind Control, can persuade him to act against it.
 * In Warhammer 40000, the Black Templars chapter of space marines, an army of particularly pious warrior monks, may choose a vows that affects how they fight a battle. One for example gives all models a weak saving throw against ranged attacks that would normally ignore their Power Armor, but keeps them from taking cover, while another forces units to charge at the nearest enemy but grants them significant combat bonuses when doing so.

Video Games

 * Shirou in Fate/stay night has an interesting personal vow. Apart from the one about saving everyone, that is. This one is about how he can accept losing to an enemy, but he refuses to let his own weakness or body get in the way. Basically, he refuses to give up until you kill him outright where he stands.
 * From Persona, Yukino Mayuzumi pledges to rescue Saeko-sama from the Snow Queen, no matter what.
 * In the Windham Classics text-adventure adaptation of The Wonderful Wizard of Oz, the Tin Man swears an oath to "Guard [the party] with my axe, and shield you with my tin" upon being recruited.
 * Valvatorez from Disgaea 4: A Promise Unforgotten has made a vow to never drink human blood until he can show a certain woman true fear. He does not care that the woman in question is long dead, the vow has depleted him of all his former power and standing, and that everybody except for him agrees that the vow is utterly unnecessary - he made a promise and he's going to keep it.

Web Comics

 * Kin of Goblins tried to free herself from Goblinslayer by escaping, but it always failed. Finally she came to the conclusion that fleeing would solve nothing, and that it was necessary for her to stand and solve her problems. So, even as she lay bleeding and weak, she swore to never run away again.

Web Original

 * The Global Guardians PBEM Universe has Thunderfist, a former Seattle cop who vowed to never violate proper police procedure when it came to evidence collection or the treatment of suspects.

Western Animation
""Much as it pains me, I have to honor the Lobe's request, the same as everyone else's... 'Cause it's in the codebook, okay? 'Cause superheroes always keep their word no matter what, okay?""
 * In Ben 10: Ultimate Alien, after Aggregor recaptures the last of his escaped prisoners, Ben makes one to save the aliens and stop Aggregor.
 * This is why Freakazoid couldn't go after the Lobe.

"Rarity: ...I've waited all my life...
 * Occurs in the My Little Pony Friendship Is Magic episode "The Best Night Ever". When the mane six's efforts to make their dreams come true fail, they each individually vow to redouble their efforts. It Gets Worse.

Fluttershy:...for this moment...

Pinkie Pie:...and I'm not going to...

Applejack:...let it slip by!...

Rainbow Dash:...If it's the last thing I do...

Twilight Sparkle: ...I'm gonna make this...

All:...the best night ever!"


 * Also appears in "Applebuck Season", with Applejack vowing to bring in the harvest without anybody's help.
 * Aang has this problem in Avatar: The Last Airbender,

Real Life

 * Google's unofficial motto is "Don't be evil."
 * Have you ever really read the Anglican Marriage vows and paid attention to what you were reading? That is meant to be taken seriously.
 * The Hippocratic Oath.
 * After the September 11 terrorist attacks, teacher Gary Weddle vowed not to shave his beard until Osama Bin Laden was captured or killed. He kept it for ten years...