The catchphrase of the Audubon Ballroom, "Shall we dance?" Though, admittedly, you could say anything and it would be badass if you happen to do it while charging head-on into a squad of Super Soldiers with Guns Akimbo.
"Sneer and be damned," indeed! Though Victor Cachat never actually says it out loud, and, again, anything said while in the process of turning super-solders into blood pudding is almost guaranteed to be badass.
Weber's good at this. One of the treecats, recognizing that the 'cats who adopt humans will have shorter-than-normal lifespans, says: "Perhaps our time will be short, but oh, how we shall blaze against the night!" (Worlds of Honor, "What Price Dreams")
And the Borderlanders stole the Bushido quote: Death is lighter than a feather, Duty heavier than a mountain
"Attack on ground where your enemy believes you will not, from an unexpected direction at an unexpected time. Defend where your enemy believes you are not, and when he believes you will run. Surprise is the key to victory, and speed is the key to surprise. For the soldier, speed is life." —Comadrin
A Kandori oath taken when a boy is first given a sword (at age 14):
Why do you draw your sword?
In defense of my honor, my family or my homeland
How long do you fight?
Until my last breath joins the northern wind.
When do you stop watching?
Speak it louder!
The oath of the Malkieri warriors:
"My arm will be the sword, my breast itself a shield, to defend the seven towers, to hold back the darkness. I will stand when all others fall. For my sweet land Malkier."
The Oath of the Malkieri kings:
"To stand against the Shadow so long as iron is hard and stone abides. To defend the Malkieri while one drop of blood remains. To avenge what cannot be defended."
Night gathers, and now my watch begins. It shall not end until my death. I shall take no wife, hold no lands, father no children. I shall wear no crowns and win no glory. I shall live and die at my post. I am the sword in the darkness. I am the watcher on the walls. I am the fire that burns against the cold, the light that brings the dawn, the horn that wakes the sleepers, the shield that guards the realms of men. I pledge my life and honor to the Night's Watch, for this night and all the nights to come.
The motto of the Faceless Men: Valar morghulis; valar dohaeris. (All men must die; all men must serve.)
Arya's "Fear cuts deeper than swords."
The various houses all have their own mottoes of a self-aggrandizing boast, but the Starks have the enigmatic and ominous, "Winter Is Coming."
In addition to their official motto, the Lannisters also have the unofficial motto, "A Lannister always pays his debts." This is usually a threat, but if the Lannisters actually do owe you money, you'll be paid, and probably with interest.
The Boltons have the saying: "A naked man has few secrets, a flayed man none.", also not their official motto.
"There is only one god, and his name is Death. And there is only one thing we say to Death: Not today."
The Bene Gesserit Litany Against Fear: "I will not fear. Fear is the mind-killer. Fear is the little death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain."
And from the movie, more of an entertaining psycho creed from the mentats... It is by will alone I set my mind in motion. It is by the juice of Sapho that thoughts acquire speed, the lips acquire stains. The stains become a warning. It is by will alone I set my mind in motion. It is by the juice of Sapho that thoughts acquire speed, the lips acquire stains. The stains become a warning...
Subverted in The Last Hero, with the creed (suggested by Rincewind) for the expedition to stop Cohen the Barbarian being Morituri Nolumus Mori, translated from Latin to English it reads as "We who are about to die don't want to."
The Nac Mac Feegle in The Wee Free Men: "Nae king, nae queen, nae laird, nae master. WE WILLNA BE FOOLED AGAIN!" In fact, the Feegle have several Badass Creeds, and a habit of shouting them all out at once in a confused mess.
Note that it's traditional to say it literally. "I comma bracket recruit's name end-bracket comma..."
Vimes has noted that the Oath is a treacherous, slippery thing. It allows the alert, considerate Watchman almost complete freedom of action to do good things. Of particular note is the single reference to upholding the actual laws of the city, numerous references to protecting and serving the best interested of the people of the city, and the total absence of any promise of loyalty to the ruler.
Dorfl: "To Serve The Public Trust, Protect The Innocent, And Seriously Prod Buttock, Sir."
A few lines later:
Nobby: "'S not going to be popular, a golem as a Watchman."
Dorfl: "What Better Work For One Who Loves Freedom Than The Job Of A Watchman. Law Is The Servant Of Freedom. Freedom Without Limits Is Just A Word.
And later, talking about his plan to free the golems: "We Are Bought And Sold. So We Will Buy Ourselves Free. By Our Labor. No One Else Will Do It For Us. We Will Do It By Ourselves.
This gets reformulated on the legend above the door of the Golem Trust in later books: "By our own hand, or none."
The fearsome dwarfish warcry in Feet of Clay: T'dr'duzk b'hazg t't! (Today is a good day for someone else to die!)
The millennia-old messenger golem Anghammarad remembers a Bad Ass version of the A-M Post Office motto from the dawn of time: "Neither Deluge Nor Ice Storm Nor The Black Silence Of The Netherhells Shall Stay These Messengers About Their Sacred Business. Do Not Ask Us About Sabre-Tooth Tigers, Tar Pits, Big Green Things With Teeth Or The Goddess Czol."
Inevitable question: The Goddess Czol?
Anghammarad: Do not ask.
Based on the inscription from Herodotus on the New York Post Office (which isn't an official motto): "Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds".
In Life's name and for Life's sake, I say that I will use the Art for nothing but the service of that Life. I will guard growth and ease pain. I will fight to preserve what grows and lives well in its own way; and I will change no object or creature unless its growth and life, or that of the system of which it is part, are threatened. To these ends, in the practice of my Art, I will put aside fear for courage, and death for life, when it is right to do so — till Universe's end.
The version of the Oath for saurian wizards:
The Fire is at the heart, and the Fire is the heart; for its sake, all fires whatever are sacred to me. I shall kindle them small and safe where there are none, for the wayfinding of those who come after: I will breathe on those fires about to die in dark places, and in passing, feed those that burn without harm to any; the fire that burns and warms those who gather about it, in no wise shall I meddle with it save that it seems about to consume its confocals, or to die. To these ends, as the Kindling requireth, I shall ever thrust my claw into the flames to shift the darkening ember or feed the failing coal, looking always toward that inmost Hearth from which all flames rise together, and all fires burn undevouring, in and of That Which first set light to the world, and burns in it ever more...
The meditation of the Feline Worldgate Team:
I will meet the cruel and the cowardly today, liars and the envious, the uncaring and unknowing: they will be all around. But their numbers and their carelessness do not mean I have to be like them. For my own part, I know my job; my commission comes from Those Who Are. My paw raised is Their paw on the neck of the Serpent, now and always. I shall walk through Their worlds as do the Powers that Be, seeing and knowing with Them and for Them, tending Their worlds as if they were mine: for so indeed they are. Silently shall I strive to go my way, as They do, doing my work unseen; the light needs no reminding by me of good deeds done by night. And in this long progress through all that is, though I will know doubt and fear in the strange places where I must walk, I will put these both aside, as the Oath requires, and hold myself to my work ... for if They and I together cannot mend what is marred, who can? And having done my work aright, though I may know weariness at day's end, come awakening I shall rise up and say again, with Them, as if surprised, "behold, the world is made new ... !"
And when the Cat-Wizard in question is feeling particularly cynical:
I will meet the terminally clueless today, idiots, and those with hairballs for brains, and those whose ears need a good shredding before you can even get their attention. I do not have to be like them, even though I would dearly love to hit them hard enough to make the empty places in their heads echo ...
The code of The Three Musketeers, which only appears twice in the original story: "One for all and all for one!"
Conan the Barbarian.
"I have known many gods. He who denies them is as blind as he who trusts them too deeply. I seek not beyond death. It may be the blackness averred by the Nemedian skeptics, or Crom's realm of ice and cloud, or the snowy plains and vaulted halls of the Nordheimer's Valhalla. I know not, nor do I care. Let me live deep while I live; let me know the rich juices of red meat and stinging wine on my palate, the hot embrace of white arms, the mad exultation of battle when the blue blades flame and crimson, and I am content. Let teachers and priests and philosophers brood over questions of reality and illusion. I know this: if life is illusion, then I am no less an illusion, and being thus, the illusion is real to me. I live, I burn with life, I love, I slay, and am content." From The Queen Of The Black Coast.
"Conan, what is best in life?" "To crush your enemies, see them driven before you, and hear the lamentations of their women." From the movie.
Psalms 144:1-2 "Blessed be the Lord my strength, which teacheth my hands to war and my fingers to fight: My goodness, and my fortress: my high tower, and my deliverer: my shield, and he in whom I trust; who subdueth my people under me.
This creed might not seem all that badass now, but picture what it must have been like 2000 years ago: "You have heard the law that says, 'Love your neighbor' and hate your enemy. But I say, love your enemies! Pray for those who persecute you!"
Life is nothing in itself. It's a place marker that proves who's winning, and we are the winners. We are always the winners. There is nothing but the winning. Even winning means nothing. We win because it's an insult to lose. - Durzo Blint
And that's not even the real creed. The true creed of the Night Angels goes as follows:
I am Sa'kage, a lord of shadows. I claim the shadows so that the Shadow may not. I am the strong arm of deliverance. I am Shadowstrider. I am the Scales of Justice. I am He-Who-Guards-Unseen. I am Shadowslayer. I am Nameless. The coranti shall not go unpunished. My way is hard, but I serve unbroken. In ignobility, nobility. In shame, honor. In darkness, light. I will do justice and love mercy. Until the king returns, I shall not lay my burden down.
...down these mean streets a man must go who is not himself mean, who is neither tarnished nor afraid. The detective in this kind of story must be such a man. He is the hero; he is everything. He must be a complete man and a common man and yet an unusual man. He must be be, to use a rather weathered phrase, a man of honor—by instinct, by inevitability, without thought of it, and certainly without saying it. He must be the best man in his world and a good enough man for any world.
Tennyson, "Sir Gallahad":
My good blade carves the casques of men,
My tough lance thrusteth sure,
My strength is as the strength of ten,
Because my heart is pure.
Tennyson again, "Ulysses"
Though much is taken, much abides; and though
We are not now that strength which in old days
Moved earth and heaven; that which we are, we are;
Even prior to this, Sofia's internal mantra of "I am Mendes", in reference to her Sephardic family's history of endurance as well as her own.
The dying words of many an heroic Bolo have been the Dinochrome Brigade's motto, "For the Honour of the Regiment!"
One particular sub-command of the Dinochrome Brigade has a Pretentious Latin Motto that doubles as a creed for the Bolos and a challenge to their enemies; translated, it simply says Stand and be judged.
From the same story, the Bolos in particular are units DBC and DBQ, nicknamed 'Chains' and 'Quarter' respectively. What does the DB stand for, you ask?
Colonel Ishida: "Death By Chains."
Unit DBC: "So judged."
From the novella A Dry, Quiet War, by Tony Daniels:
They sucked down my heart
to a little black hole
You cannot stab me.
They wrote down my brain
on a hard knot of space,
You cannot turn me.
from the eye of a star
I've come to kill you.
Rudyard Kipling's poem "The Overland Mail" shows that native postmen in India were Bad Ass. The poem specifically states he's doing all this at night ... in the jungle ... uphill:
Is the torrent in spate? He must ford it or swim.
Has the rain wrecked the road? He must climb by the cliff.
Does the tempest cry halt? What are tempests to him?
The service admits not a "but" or an "if."
While the breath's in his mouth, he must bear without fail,
"Life before death, strength before weakness, journey before destination."
This is actually only the First Ideal of the Knights Radiant, which is shared by all ten orders, each order also has four other ideals of their own. The Second Ideal of the Windrunners is "I will protect those who cannot protect themselves". The Second Ideal of the Edgedancers is "I will remember those who have been forgotten". The Second Ideal of the Bondsmiths is "I will unite instead of divide, I will bring men together". The Third Ideal of the Windrunners is "I will protect those I hate, so long as it is just".
The world is getting weirder. Darker every single day. Things are spinning around faster and faster, and threatening to go completely awry. Falcons and falconers. The center cannot hold. But in my corner of the country, I'm trying to nail things down. [...] I don't want to live in a world where the strong rule and the weak cower. I'd rather make a place where things are a little quieter. Where trolls stay the hell under their bridges, and where elves don't come swooping out to snatch children from their cradles. Where vampires respect the limits, and where the faeries mind their p's and q's. My name is Harry Blackstone Copperfield Dresden. Conjure by it at your own risk. When things get strange, when what goes bump in the night flicks on the lights, when no one else can help you, give me a call. I'm in the book.
"I was made for Abhorsen to slay those already dead. The Clayr saw me. The Wallmaker made me. Abhorsen wields me so that no Dead my walk in life, for this is not their path."
The Pulp incarnation of The Shadow had "The weed of crime bears bitter fruit. The Shadow never fails", in addition to the Radio Shadow's "Who knows what evil lurks in the hearts of men?"
Two of them in The Truth of Rock And Roll: "It's about rockin', not remembering" and “That’s what Rock and Roll really is, you know – beneath all the motorcycles and cars and leather jackets – it’s about being young and being brave. Young leaves us all, but you have to let Brave go of your own free will.
The Dauntless manifesto from the extra materials of Divergent.
We believe that peace is hard-won,
that sometimes it is necessary to fight for peace.
But more than that:
We believe that justice is more important than peace.
We believe in freedom from fear, in denying fear the power to influence our decisions.
We believe in ordinary acts of bravery, in the courage that drives one person to stand up for another.
We believe in acknowledging fear and the extent to which it rules us.
We believe in facing that fear no matter what the cost to our comfort, our happiness, or even our sanity.
We believe in shouting for those who can only whisper, in defending those who cannot defend themselves.
We believe, not just in bold words but in bold deeds to match them.
We believe that pain and death are better than cowardice and inaction because
We believe in action.
We do not believe in living comfortable lives.
We do not believe that silence is useful.
We do not believe in good manners.
We do not believe in empty heads, empty mouths, or empty hands.
We do not believe that learning to master violence encourages unnecessary violence.
We do not believe that we should be allowed to stand idly by.
We do not believe that any other virtue is more important than bravery.
The Oath taken by the residents of Atlantis in Atlas Shrugged: "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."
The creed used by the agents in Ari Bach's Valhalla is simple yet very effective:
"Don't fuck shit up."
In The Zombie Knight, the Rainlords of Sair have a motto summing up their take on enemies and danger.