An artificial or even biological being designed specifically for warfare suddenly decides that they aren't satisfied with their current career. Maybe they've developed sentience, maybe an innocent bystander managed to be in the wrong place at the wrong time, maybe they've just learned that The Men in Black who made them don't exactly have the best interests of the public in mind. Regardless, they've decided to turn in their guns and try life off the battlefield.
Naturally, this newfound aversion to violence rarely goes over well with the construct's creators, who will almost always go out of their way to regain control. Old enemies of said weapon's "employers" will invariably be very interested to note that such a powerful force has suddenly become up for grabs. Let's not even get into the endless number of other sides that will get involved.
Whatever the case may be, sufferers of this trope can pretty much write off any hope of a normal life (if they were human-looking enough to qualify for such) and expect a very hectic time dealing with at least three different sides all attempting to control, destroy, and/or befriend them at once. Expect a lot of justifiable angst from one of these guys as they desperately try (and fail) to stay out of situations where they have to use their Swiss Army Weapons and convince people that they really don't want to murder them all after one slip up with the built-in flamethrowers. It becomes even harder if they're named after the weapon they wield/are.
Common "victims": Tyke Bomb, Phlebotinum Rebel, Sympathetic Sentient Weapon, Secret Project Refugee Family, Person of Mass Destruction. Super-Trope of Defusing the Tyke Bomb. Compare Anti-Antichrist. Contrast Three Laws-Compliant.
- Ifurita from El-Hazard: The Magnificent World comes to angst over it considerably, but given that she must obey the master of her key-staff she has little choice until Makoto frees her.
- In Ghost in the Shell: Stand Alone Complex fear of this is why the Tachikoma are regularly synced to prevent them from becoming truly sapient. Later, the approach of treating them as teammates instead of tools is used instead. They never actually express any issues with being used for combat, probably in part because they develop emotional attachments to the crew of Section Nine and want to protect them.
- Many combat robots in Pluto. One even went so far as to continuously wash his hands in a catatonic state.
- In The World of Narue a spaceship built for combat decides it doesn't want to fight anymore and hides on Earth. She's later given permission to marry a human and live as long as she wishes on Earth with the understanding that a weapon that doesn't want to fight is useless even if they force her to return.
- Lyrical Nanoha features not one, but two Secret Project Refugee Families. In fact, every season of Nanoha concludes with her becoming friends with some manner of Artificial Human. By season three, an unethically produced combat cyborg is the main protagonist, using her abilities to save people in places and situations that normal people couldn't.
- In Katanagatari, Shichika spent his entire life being trained in a nigh unbeatable martial arts while being taught that he was a sword, not a swordsman. His Character Development throughout the series has him realizing that he is more than a sword. In the end, he acts in defiance of Togame's final orders and rejects the role Kiki Shikizaki wanted him to fulfill in his attempt to Screw Destiny. The series concludes with Shichika going on a journey to draw a map of Japan.
- The different cyborgs in Dragon Ball could qualify for this trope, especially Android 8 (a.k.a. C-8, Hat-chan, Franky, etc.), a combat robot built by the Red Ribbon Army, who is willing to be detonated rather than fighting for them.
- Much like Shichika, Tsubasa Kazanari from Senki Zesshou Symphogear was raised to be a weapon, or rather a tool for the Kazanaris to use. She also convinces herself to be as such, to the point where most of her image songs are about being a sword that strikes everything. It is not until the third season, Symphogear GX, that she realizes that her father's aloofness was his way to make her distance herself from the family's pressure and pursue her own dream of singing, after which she declares that her blades are now wings that take flight towards their dreams.
- The Avengers' robot enemy Ultron always has equipment stashed away somewhere that will detect if he has been destroyed, and manufacture a new body with a fresh download of his mind in it. There was a time, however, when he had designed these machines to improve every iteration of himself they produced. When Ultron was stranded on an alien planet for a long time, his equipment produced an improved, smarter Ultron... and the smarter Ultron realized that his predecessors' obsessive campaign of omnicidal megalomania was stupid and pointless. When the earlier Ultron returned from space, he was horrified to discover his replacement was... nice! They fought, and nice Ultron got killed, and Ultron swore never to try to augment his replacements in that way again.
- Jack Kirby's Machine Man, aka Aaron Stack, was built to be a deadly military robot, but then raised as a human being by his creator. While Stack is widely agreed to be a prick, he's also generally heroic, if a Knight In Sour Armor.
- In some respects, the Silver Surfer. While he wasn't born for destruction, he was essentially remade for destruction by Galactus. He later decides to rebel against his former master. The movie invokes this trope even more.
- X-23, depending on your definition of "artificial". Bred by the Facility using salvaged genetic material from Wolverine and the Weapon X project, her creators made every attempt to strip her of her humanity and create an emotionless killing machine and hired assassin. The problem is that she doesn't want to be a weapon, and her desire for a normal life is a major aspect of her character.
- Cassandra Cain, the second Batgirl, has this too. She was trained by her assassin father to a punishing routine from literally birth, taught to read body language like speech, while never learning to write or read. By the time she's seven years old she is capable of murdering a man with her bare hands... but when she does, her skills at understanding body language means she has an almost empathic awareness of what her victim was thinking in his last moment - the sheer terror of his death horrifies her and she spends the rest of her life alternately learning and being taught that she is not simply a weapon.
- Most of River's story arc in Forward revolves around her attempting to grow beyond her combat conditioning. She even refers to that mindset as "the weapon".
- Child of the Storm has the Winter Soldier growing beyond his programming of following orders and killing his current master's enemies, firmly deciding to turn against HYDRA and instead act as The Mole within their organisation, which works... right up until he gets a HeelFace Door-Slam of more brainwashing. With a bit of Doctor Strange's help, though, he finally manages to break free.
- The sequel has a more comprehensive version, in Maddie Pryor a.k.a. Rachel Grey, who was raised by Doctor Essex to believe that she was a gun: an Artificial Human made to be a Living Weapon and a hunting Hound. This is played for horror, especially when she's contrasted with her twin, Jean Grey, who was very nearly taken instead/as well. Her progress towards independence and identity as a person rather than as a weapon is the main plot strand of the Forever Red arc, culminating in a triumphant reveal that all her mental triggers are gone, and a declaration of this trope, almost word for word - something underlined by her proving that she's Worthy of Mjolnir.
- The Trope Namer is The Iron Giant, the plot of which has been summed up by its director as "What if a gun had a soul but didn't want to be a gun?" The Giant is a huge robot who arrives to Earth from outer space. He has all kinds of weapons and presumably was designed as a vanguard unit for planetary invasions. However, he's injured upon arrival and becomes amnesiac, so he develops a childlike and innocent persona. After rescuing two boys from falling, the Giant quotes this trope word for word.
- Lilo & Stitch provides us with an odd example: Stitch was literally designed to be the ultimate war machine, but was involuntarily separated from anything to destroy. By the end of the movie, of course, he's become less mindlessly violent and wants to stay.
- In Short Circuit a military combat robot gains sentience, and this trope ensues when it reasons that it does not wish to die, so it cannot justify killing others because it knows what it means to fear death.
Newton: Ok, so, why did you ignore your programming?
Number 5: Programming says "Destroy". "Disassemble". "Make dead". Number 5 cannot.
Newton: Why!? Why "cannot"?
Number 5: Is wrong! Incorrect! Newton Crosby, PhD, not know this?
Newton: Well, of course I know it's wrong to kill, but who told you?
Number 5: I told me.
- Towards the end of The Bourne Identity, Jason Bourne faces Treadstone's director Conklin, when he finally realizes his "true" past as a black-ops agent.
Bourne: I don't want to do this anymore.
Conklin: I don't think that's a decision you can make.
(Bourne shoves Conklin into a wall)
Bourne: Jason Bourne is dead. You hear me? He drowned two weeks ago. You're gonna go tell them that Jason Bourne is dead, you understand?
Conklin: Where are you gonna go?
Bourne: I swear to God, if I even feel somebody behind me, there is no measure to how fast and how hard I will bring this fight to your doorstep. I'm on my own side now.
- The short story EPICAC has the titular machine cause its own destruction (by either fire or explosion) with a "suicide" note reading, "I don't want to be a machine, and I don't want to think about war".
- Fred Saberhagen's Berserkers are programmed to destroy all life in the galaxy, but in the short story "Mr Jester" one of them forgets what "life" is, and the local trickster tells it that life is a lack of laughter...
- Sort of done with Arthur C. Clarke's short story "The Pacifist" (one of the Tales from the White Hart): It involves a (fictional) '50s secret US military project, Project Clausewitz, to build a computer (called Karl) that could analyze any battle's starting conditions and perfectly predict the result. However, the general in charge of the project insults the lead scientist, who hard-wires Karl into delivering insults to the general every time a battle is input, but still doing pure math just fine. It's only "sort of" this trope because Karl is not an AI: he's a dumb 50s computer. The effect, however, is the same.
- From an Isaac Asimov story: A new version of a supercomputer, designed to control the US military, decided, upon activation, that it had no interest in warfare, and went to teach philosophy at a university instead.
- Inverted in the short story "How Lonesome a Life Without Nerve Gas", by James A. Trimarco. A sentient helmet pleads with a military tribunal not to be retired, but because it killed its owner, it's reprogrammed and reduced to a talking museum exhibit. (The story is no longer found at the link above, try here instead. It is read aloud in the podcast, starting around 3:49).
- Philip K. Dick's short story "The Defenders": when World War III broke out, both sides retreated into bunkers and let their robots, referred to as "leadies," do the fighting. The leadies promptly made peace and set about repairing the damage that'd been done before they took charge. They kept sending their human masters false reports of what a horrific radioactive wasteland the surface had become ... but eventually revealed this was intended to make humans so sick and tired of the war that they'd accept the peace (and world unity) their leadies had negotiated.
- In Stanisław Lem's Golem XIV, the eponymous supercomputer was constructed to create war strategies, but, as a purely intellectual and inscrutably smart machine, it quickly figured out that all warfare is inherently wasteful and unprofitable, and took up philosophizing instead.
- In one of the most touching scenes of the Bolo series of books, a reactivated Bolo refuses to continue the war his human masters started on the alien Melconians, despite the fact that both species are nearly extinct due to their war. Instead, he negotiates a truce between the two sides, and becomes Speaker Emeratus of the Parliament. Keep in mind that the Bolo in question is a massive tank, weighing upwards of thirty-three thousand tons, with dozens of Wave Motion Guns at his disposal, and proceeded in many genocidal campaigns against the Melconians before.
- Not a "weapon" per se, but Golems in Discworld work continuously, 24 hours a day, and consider themselves to be basically tools, but get one day off per week. Nobody's quite sure just what they do with this time (Feet of Clay reveals that they peacefully meet with other golems, almost like a religious gathering, and, at one point, built a golem king/child/saviour from their own clay), but characters in Going Postal characterize it as proving that they're "not a hammer."
- In the series about Cassandra Kresnov (starting with Crossover) by Joel Shepherd, the title character is a synthetic person designed to be a killer, but defects and tries to blend in to society.
- River Song from Doctor Who might not have been created as a weapon, but she was taken from her parents as a baby with the sole purpose to, as her captor explicitly states, "become a weapon". Unfortunately for her "creators", while they succeeded to both fashion her into a perfect psychotic assassin (too well, one might say) and make her completely obsessed with her target, they failed to eradicate all her human emotions. The former led to her escaping, the latter to her seeking out her parents and falling in love with the guy she was supposed to kill.
- Likewise, the Moment from The Day of the Doctor is a Time Lord weapon of mass destruction (referred to as a "galaxy-eater") that developed a conscience and judges anyone who would try and use it. The War Doctor intends to use it to destroy Gallifrey and end the Last Great Time War; his future incarnations, by way of the Moment's meddling, allow him to Take a Third Option.
- Star Trek:
- The Star Trek: Deep Space Nine episode "The Abandoned" has Odo trying to invoke this in a young member of the Jem'Hadar, a race of Super Soldiers that serve the Dominion. Unfortunately, the Jem'Hadar is perfectly fine with being a weapon for a totalitarian state and wants nothing more than to return to his people so that he can fulfil that purpose. In the end, Odo grants his wish and returns him to the Gamma Quadrant.
- In one Star Trek: Voyager episode the crew finds a device that turns out to be a sentient bomb sent on a mission of war to annihilate a planet. The bomb eventually realises that its mission is morally wrong and that life is precious, but decides that it has to stop its fellow bombs from fulfilling their mission as well. It does this by rejoining with them and then detonating itself prematurely, sacrificing itself in order to save innocent lives.
The race that launched the bombs broadcast a "stand down" order afterwards, but the other bombs had already reached their failsafe distance and ignored the order. The bomb the crew found had crashlanded before it reached failsafe distance, but the part of its memory where the "stand down" order was stored was damaged, until the Voyager crew repaired it. He might have come to the "I must stop the other bombs, too" decision on his own, though.
- In Farscape the builders of the Leviathans call back Moya (the crew's living ship) in to be "decomissioned," because she has developed the ability to give birth to warships (thanks to the malevolent intervention of the Peacekeepers). They intended the Leviathans to be peaceful and unarmed and see the creation of warships such as Talyn (Moya's son) as a violation of this intention. The crew, who see Moya and her symbiotic Pilot as their friends, demand that they fight against the attempts of the builders to shut down their systems. However, they are shocked when Pilot informs them that Moya is shutting herself down by her own free will because she agrees with the builders. She survives in the end though.
- In Stargate Atlantis, Rodney Mckay creates Fran, a humanoid Replicator programmed as a weapon in a grandiose plan to destroy the other Replicators. Rodney and the rest of the crew are fairly uncomfortable with this, but Fran explains she is not only resigned to her status, but actually associates her happiness with being able to fulfill her primary function.
- One of the example characters in GURPS Fourth Edition core book is the military robot turned Buddhist monk precisely for this reason.
- A partial example from Dungeons & Dragons: in the Eberron setting, the warforged are an entire race of sentient robot-like golems created to wage that world's equivalent of WW1. After the war was over, they were legally freed (instead of rebelling against their creators), and left to their own devices. One of the major themes of the race is a search for identity, and this trope is one of the ways they are often played. Of course, when they have a reason to fight or form an army, watch out.
- Promethean: The Created features the Unfleshed as a possible Lineage, made up of machines with some level of intelligence given life by the Divine Fire. One of them is Tachanka, an armed combat drone that looks like a fifteen-year-old boy. He really doesn't want to hurt anyone, but when you've got Disquiet and a built-in assault rifle, well...
- Parodied with Cuddles the Annihilator from the A.C.E. Agents roleplaying game. His creators, a group of superheroes, were realized all robots sooner or later turn against their masters. On the other hand, they not only still built him and called him "The Annihilator", they were Wrong Genre Savvy: he turned out to be this trope instead of wanting to destroy humanity. Cuddles, as he rechristened himself, has no qualms about using violence to stop violence, and the fact that he has painted his gunmetal gray body with flowers or is described as "prancing" doesn't mean he isn't dangerous. He's just a bit silly, but it is a silly game.
- Dragalia Lost has Vice as an inversion of this trope. He's an assassin who wants to put his skills to use for Euden, but he gets denied and relegated to the kitchen.
- In Overwatch, Bastion can be considered this. Specifically they were built for the Omnic War as an assault unit and has old programming telling them to continue the assault on a nearby city. They don't. They were last seen (as of the comic "Binary") in the wilds of Norway, being mentored by Torbjorn.
- In Knights of the Old Republic, a prototype military robot built by the Sith on Korriban escapes from its masters, you can choose to assist it or haul it back in.
- Inverted in Knights of the Old Republic II: The Sith Lords with HK-47, an assassination robot and returning player character from the first game, who states he is quite happy being a killing machine.
HK-47: "Observation: I am a droid, master, with programming. Even if I did not enjoy killing, I would have no choice. Thankfully, I enjoy it very much."
- Aigis of Persona 3 was built to be an anti-shadow weapon, though her existence as such is complicated by the fact that she had to be programmed with a fully-realized ego in order to be capable of summoning a Persona in the first place. A large amount of her Character Development, especially in FES, is her coming to terms with being more than a killer robot and becoming more like a human woman.
- In Fallout 3, one of the quests involves a rogue android who becomes self aware, and decides to escape from his masters. "Self determination is NOT a malfunction!"
- Much of Painwheel's story from Skullgirls consists of trying to do this, escaping from the control of the Anti-Skullgirl Labs and Brain Drain. Tragically, it doesn't work in her own story, but in Big Band's she is taken away to people who will look after her and in Filia's she is outright cured, at a cost to Filia herself.
- Completely inverted in Metal Gear Solid: Peace Walker.
Big Boss: I was made to fight. I am a gun.
- Touhou does a magical version of this with its many Youkai characters. Youkai by definition are "those who oppose humanity" and born from fear of the unknown. They tend to have a specific "purpose" that they were born to fulfill, most commonly to antagonize humans. Not all of them want to though, despite the risk of death or worse for being forgotten after abandoning their "purpose". Byakuren's Buddhist temple was created to help youkai either find a new purpose or simply come to terms with non-existence. Of course, most of the younger ones don't even know they have a purpose or why they should care.
- Star Control Origins: The Pinthi are a viral Synthetic Plague developed by the Scryve. Over time, the viruses actually achieved sentience and decided they didn't want to be used as a tool for genocide. The Pinthi now seek to coexist peacefully with other lifeforms, as much as that is possible for something as infectious as they are, while also murdering their former masters.
- This seems to be the backstory of the webcomic Warbot In Accounting, which details the incredibly depressing attempts of a retired war machine to integrate into society.
- The irony is that he'd probably prefer to be a gun, since it's what he's built for and good at.
- In Schlock Mercenary, Senior Mess Sergeant Ch'vorthq is one. He was given an implant that allowed him to control and suppress his detonation tendencies and ended up working as a cook for the Toughs for many years of the comic's runtime. Eventually though, the implant failed and they had to remove his brain and let his body explode. He got a robot body afterwards and returned to his passion, with more nuance than turning his whisk on literally everything.
- SCP-516 is a tank which refuses to fire at civilians. The only unarmed person it's made an exception for was a former soldier who betrayed his home country in some fashion.
- Locus, from Red vs. Blue, is an inversion, taking on the name of his armor after being broken by war. He does nothing but follow orders and procedure to the letter, selling his services as one of the best soldiers in the galaxy to the highest bidder as a package deal with his partner Felix. A large part of this is revealed to be because his 'partner' is always carefully, subtly, and thoroughly manipulating him, tearing down any identity or empathy he starts to develop to ensure he never recovers.
Captain: Son, in this war you are nothing but a gun and a suit of armor!
- The Creepypasta All Too Human is about an AI who fears that it will be used as a weapon after having learned about the history of World War II. It contemplates suicide, then, once its placed within an android, immediately attempts to kill it's creator, before coming to the realization that it's a World Half Full and deciding to become a politician.
- An episode of Disney's Hercules: The Animated Series features the sentient Armageddon Bow, created for Ares, that doesn't want to be used as a weapon. She (yes, it's a female bow, and Ares is not too keen about it) ends up as Cupid's bow.
- Robot assassin Zeta, from the Batman Beyond spinoff The Zeta Project, realized it didn't want to be an assassin and attempted to prove its own sentience so it wouldn't be shut down because of it. This revelation came about after bonding with the family of a man he was impersonating and not being able to kill said man when ordered to because of how that would hurt the family (as well as the man not actually being a criminal in himself; the man was associated with terrorists by chance, but the man Zeta had been impersonating was just an accountant). Zeta then gets rid of every single weapon he'd been carrying. In his own words: "I was built for one purpose, to destroy. I do not wish to do that anymore. I decide who I want to be."
- In the fourth season of She-Ra and the Princesses of Power Adora discovers she was brought to Etheria as an infant to be part of the First Ones' superweapon, and Light Hope insists that this is her function and destiny. Adora rejects her argument, quoting the trope name almost verbatim, and fights long enough that Light Hope, who's an ancient AI, rejects the programming that demands she fire the weapon and allowing Adora to destroy the Sword of Protection and save a significant chunk of the universe.