You can tell how good The Hero or bad the Villain is by how deep their scars were cut. Take it a few steps further and then imagine the kind of stories one can tell when they're missing a leg. Or two.
Artificial Limbs are commonly given to amputees to help them function pragmatically and to give them a sense of normalcy. Prosthetics can range from simple wooden legs and hook-hands, to robotic arms to even fully-functioning clone limbs made of artificial plasma-gel.
Heroic-types usually try to make their arms and legs look similar to their original ones. If they could not put artificial skin of some kind on it, they at least try to make it look as unrobotic and nonthreatening as possible. Bad guys on the other hand try to make their robot arms and legs as bulky and obvious as possible, showing it off to show that they will NOT be a victim again, not unlike how one would brandish a gun in their belt to intimidate. At times they could even see their non-robotic components as a weakness, losing more and more of their humanity as they replace their bodies with soulless tech. Some really nasty types have artificial limbs with permanently-installed weaponry.
Another related pattern is how the character got the augments in the first place. Almost always the Good Prosthetic was installed either because of the medical necessity (replacing a missing arm) or without the consent of the recipient, while all cases of voluntary cybernetic enhancements result in Evil Prosthetic and treated as the morally wrong thing to do.
Character Alignment may also depend on how they lost their limbs in the first place. They could have lost their legs saving a child from a drunk-driven truck, losing their eye trying to rob some old lady or something as simple as losing a finger or five in the garbage disposal.
- Played straight in the original Fullmetal Alchemist from 2003. Good guys like Edward and Paninya have streamlined automail which mimics the proportions of normal human limbs to the point that it can pass for the real thing provided the character is wearing long sleeves/pants and gloves/shoes. Antagonists, such as Frank Archer or the train bandit, have bulkier automail which is heavily weaponized and impossible to hide. The original manga and Brotherhood avert this by including heroic characters like Lan-Fan and Buccaneer whose automail limbs are clearly built for combat.
- Cowboy Bebop has a variation with two of the main characters. Former police officer Jet Black has a mechanical right arm, while ex-assassin Spike Spiegel has a fake eye. For the former, it symbolizes his willingness to confront danger and his humility; he could have had the arm reconstructed, but goes with the prosthetic to remind himself to watch himself better. For Spike, the prosthetic is a symbol of how he's not fully cut off from his past and is something of a Retired Monster.
- In the How to Train Your Dragon franchise, artificial limbs are a recurring element among the vikings of the Barbaric Archipelago. Due to a harsh environment, savage dragons and even savager vikings, loss of limb is rather commonplace.
- The protagonist of the series, Hiccup Horrendous Haddock III, loses his left leg after defending his village from and evil dragon called the Red Death. Not only does his prosthetic leg match the prosthetic tail fin he built for Toothless (making them even), but it can be seen as a badge of honor for defending his people and wears it proudly.
- The Evil Counterpart to this can be seen in the antagonist of How to Train Your Dragon 2 Drago Bludvist. He lost his arm at a young age seeing his whole village destroyed by dragons. He manages to hide the stump with a false arm, and is generally a bastard.
- Rule of Symbolism takes this a step further, as while Hiccup is missing a leg and deals with dragons with a gentle hand, Drago is missing his arm and deals with dragons by crushing them beneath his heel (literally in Hookfang's case).
- Gobber, who frequently serves as a comic relief character, has lost both an arm and a leg to the same dragon. He uses a peg leg and has interchangeable attachments for his prosthetic arm.
- Star Wars: At the end of The Empire Strikes Back, Darth Vader cuts off Luke's hand with his lightsaber, and Luke replaces it with a prosthetic with synthetic skin that looks nigh-indistinguishable from a real hand. It's only exposed as a cybernetic when it gets shot by blaster fire in Return of the Jedi, and is a sign that despite everything Luke's keeping his humanity. By contrast, the prosthetic arm Anakin gets in Attack of the Clones after Count Dooku severs his real arm is brass and obviously robotic, the only thing concealing it being a thick leather gauntlet rather than any synth-skin. This sets up his eventual fall to the Dark Side as Darth Vader, during which he loses the rest of his limbs and is confined to a life-support armor. Much later when The Last Jedi rolls around Luke's cybernetic hand is completely skinless and skeletal, symbolizing that, while he hasn't become evil, he's certainly given up being the good hero in favor of Death Seeking self-loathing. When he decides to be the good hero one final time, he's sporting a brown leather glove to hide the skeletal hand.
- UrTih the Alchemist and his skeksis counterpart SkekTek the Scientist from The Dark Crystal both possess prosthetic arms and legs. UrTih wields a right arm and leg carved from wood, while SkekTek had robotic prosthetics. Because the two were once a single entity, they both probably lost their limbs at the same time. What's even more disturbing, it is mentioned that SkekTek did it to himself out of mix of scientific curiosity and sadomasochism, with UrTih just sitting there taking it as his limbs fell off bleeding without rhyme or reason.
- Imperator Furiosa in Mad Max: Fury Road possesses a make-shift Diesel Punk left arm that she is more than capable of functioning without. This is in contrast to The Antagonist Immortan Joe, a Dark Lord on Life Support kept alive through a breathing apparatus designed to look like a menacing skull mask that gives him Vader Breath.
- Inspector Gadget: Gadget has an entire cybernetic body stuffed with all manner of bells and whistles, yet it's otherwise indistinguishable from the human form. Meanwhile, Claw is mostly human, but has replaced his left hand with a sinister, ferocious-looking, stainless-steel pincer that's as much a weapon as an appendage.
- Warhammer 40,000::
- Many Imperial soldiers sport some form of Used Future prosthetic, but the Adeptus Mechanicus use the degree of prosthetic replacement as an indicator of rank, seeking to one day make themselves wholly mechanical.
- Chaos prosthetics tend to be spikier and more weaponized. The Obliterators are former Mechanicus troops who found themselves melding with their prosthetics, to the point where they now function as a living Swiss Army Weapon.
- Ork prosthetics, on the other hand, are as big, brutish, and utilitarian as their owners.
- And then there's Commissar Yarrick, a human with a prosthetic arm and Powerful Pincer... a prosthetic arm he ripped from the corpse of the Ork who'd just chopped off his arm. He also has a human-made laser-shooting bionic eye, which he obtained after learning the Orks thought he could kill with a glance.
- This trope is present In-Universe in Shadowrun: Obvious cybernetic limbs, especially if they're not covered in appropriate clothing, tend to be viewed with suspicion (or at least as gauche) in polite company and reduce your social skill rolls because people think you're up to no good. Lifelike-looking cybernetic limbs (designed to look like a natural limb for the wearer) do not suffer this penalty, but are more expensive and have less internal space for useful (and illegal) modifications. Depending on the character's role in the Caper Crew, subtle cybernetics may be the way to go.
- Augmentations in the Deus Ex series run the gamut from barely noticeable to barely human, but the good guys tend towards the subtle. For example, Adam Jensen of Human Revolution and Mankind Divided has all four of his limbs replaced, but his Badass Longcoat is custom-tailored to conceal his augments and allow them to operate without taking it off. His co-worker and pilot, Faridah Malik, only has neural augmentations and looks entirely normal on the outside. You may never even realize she's an augment unless it comes up in conversation (like if you try to use the CASIE mod on her) or you find her corpse on a harvester's scrap table if you fail to save her. Jaron Namir, on the other hand, has full-body augmentations that make him look like a cadaver with no skin below the neck.
Simons: You take another step forward, and here I am again, like your own reflection repeated in a hall of mirrors.JC: That makes me one ugly son of a bitch. How'd my face get marked up by bio-electrics?
- In the first game, JC even lampshades this trope when confronting Walton Simons, a fellow nano-Aug who got the ugly end of the stick:
- Each Lokomo in The Legend of Zelda: Spirit Tracks requires an automatic wheelchair to move. The only exeception is Bryne, a rogue Lokomo who has a mechanical left arm equipped with a set of Wolverine Claws. He can use it for hand-to-hand combat or launch it like a grappling hook.
- Overwatch is chock full of examples played straight and otherwise. Of the characters with confirmed prosthetic limbs, we have:
- Doomfist, a mercenary/terrorist whose primary weapon is the massive gauntlet that he wears over his right arm; both his arms are themselves quite intimidating prosthetics. Doomfist is one of the few confirmed antagonists in the game, and his gauntlet is twice as large as his left arm, decked out with spiked knuckles, and features a prominent set of horns on the shoulder.
- Genji, a former yakuza and current Cyber Ninja under the employ of Overwatch whose injuries were so severe that 3/4 of his limbs and most of his torso had to be rebuilt with cybernetic prostheses. Genji is a rogue operator, but ultimately he strives to atone for his past actions. While undoubtedly mechanical looking, his body maintains basic humanoid proportions. Notably, in the Uprising comic (and the skin which was unlockable in the event) his cybernetic parts are Red and Black and Evil All Over, much more angular and expose a lot more wiring and bare skin. It's made clear that at the time he was still working for Blackwatch, and had yet to find the peace he has in the present.
- McCree, a former teenage arms dealer and gang member who was taken in by the titular organization. His bulky (but proportionally sized) mechanical hand and forearm are decorated with a prominent skull, hearkening back to his criminal past.
- Junkrat, an Australian scavenger and international criminal. In keeping with his chaotic nature, his prosthetic arm and leg appear to be cobbled together out of scrap metal and discarded parts. His peg-leg also forces him to walk with a distinctive limp.
- Torbjorn, a brilliant but jaded engineer who worked for Overwatch. His left arm appears to have been replaced by a set of Power Pincers, and his right eye is covered by a mechanical looking eye patch.
- Symmetra's sleek, white cybernetic arm was given to her by Vishkar, an organization that secretly commits atrocities with the goal of establishing order.
- The members of Team Star Fox in the Star Fox all possess identical metal prosthetics to to better endure the G-force their line of work entails note . In contrast, many of the bad guys possess artificial body parts varying in variety. Andross survives his battle in Star Fox and reappears with a false eye in Star Fox 2. General Scales from Star Fox Adventures possesses a primitive two-hooked false hand. Fox's rival Wolf O'Donnell has worn an eye patch through most of the series, ungrading to a technological false eye by Star Fox: Assault.
- BlazBlue: Played with by the hero, Ragna the Bloodedge. The man isn't all that heroic at first, merely going against The Empire because one higher-up in its army pissed him off (that, and his master Jubei and benefactor of sorts Rachel guided him). He's got an artificial arm as he lost the original one to his brother back when they were still children. The new arm he gets, called Azure Grimoire, is nasty: it's permanently black-colored, has a few red veins running on it, and it gives him the power to steal people's souls. Oh, and the Azure Grimoire is made from the corpse of an Eldritch Abomination that destroyed civilization almost a century ago. Due to the events of the games (especially comes the third game), however, he slowly and surely becomes a Jerk with a Heart of Gold who finds a new purpose in life. His prosthetic doesn't change any, though.
- Final Fantasy XV: High Commander Ravus Nox Fleuret of the Niflheim Empire has had his left arm replaced by a metallic prosthetic that looks like the gauntlet of a Tin Tyrant's armour suit. Kingsglaive and Episode Ignis reveal that he was present during the false-treaty betrayal in Insomnia. When King Regis was killed, Ravus picked up the Ring of the Lucii and slipped it onto his finger, believing that he was the one destined to cleanse the Starscourge. The Ring, carrying the souls of past Kings of Lucis, deemed him unworthy of Lucian power and incinerated his arm.
- RWBY: The protagonists who have prosthetic replacements have limbs that are made with advanced Atlesian technology which function like their missing limbs and also incorporate their style of fighting to ensure they can still function as Huntsmen. General Ironwood uses clothing to completely hide the prosthetic part of his his body, even when it means wearing one hand gloved and one hand ungloved, and he only uses his prosthetic arm in battle against the Grimm where its great physical strength allows him to fight without weapons. The Volume 3 finale sees both Yang and Cinder lose an arm which is replaced in Volume 4 by General Ironwood and Salem respectively. Yang chooses to paint her prosthetic in her signature colour scheme (yellow with black accents), incorporating it into her asymmetrical fashion style and therefore displaying it openly. Cinder hides her prosthetic behind an overlong sleeve which allows her to use her new arm as a surprise attack: her new limb is a Grimm arm which is capable of stretching well beyond its normal range. It also enables her to easily steal the power of other Maidens by absorbing it as her victim dies in agony.
- In Kiwi Blitz, villain Gear has a chainsaw like object as her left arm. So far, she is generally unsympathetic. Good guys Steffi and Reed both have prosthetic limbs, but they mostly serve as non-weapons and they lost their body parts trying to save others.
- Yuri loses all four of her limbs and takes the opportunity to become fully transhuman. She upgrades her prosthetics multiple times during the comic. As she lets bloodlust and post-traumatic stress take over, her prosthetics become increasingly inhuman—for example, giving herself the body of a giant spider or mantis. Near the end, she crosses the Bishōnen Line, and her most powerful form looks human again.
- After Martina loses her arm, she has it replaced with a prosthesis that looks and functions exactly the same as her human arm, refusing to trade her humanity for firepower because she'd seen how it affected Yuri.
- Ducktales 2017 provides an example with Della Duck and Black Heron. Della ended up losing her leg in a rocket crash on the moon; replacing it with a prosthetic made from scrapped parts. She is an eccentric from being away from earth for ten years; but is ultimately good-hearted. Heron, however; is an Agent of F.O.W.L. who lost one of her arms in a fire during a mission with Beakley, replacing it with a mechanical one when she's next seen.