Unlike humans, robots aren't (usually) driven by emotional and irrational whims, don't need to take breaks, and can work efficiently based on their hardwired objectives and skills. So, it's no surprise that if a human is unable to do their job, a common solution is to replace them with a robotic version of themselves. Robots are more reliable, right?
Wrong. After being built to replace somebody, things start to go south. This is typically because the robot is a cold, emotionless machine who only cares about the end result and as a result does their job either without passion, without concern for anybody else, or with the willingness to dominate and destroy whoever gets in their way. In addition, robots, being machines, typically have a one-track mind and lack the ability to think creatively, making them unreasonable and too rule-oriented.
This may also be because robots, being machines, can malfunction and glitch. One more alternative is because the robot turns out to be just as irrational and flawed as the original human, but without the same memories, skills and personality, they can't do the job as well. Robots taking the place of people with authority, such as a parent or boss, are especially prone to becoming controlling and dominating, often contrasting the original person they replaced.
Sometimes it goes well at first, but through any number of reasons, the robot will go from helpful and competent to creating problems or outright harming people. Often, this is due to someone messing with it, like changing their settings or attempting to shut them down. In some cases the robot is so competent that someone decides to mess with it out of spite or insecurity.
A subtrope of Ludd Was Right. Compare A.I. Is a Crapshoot, Evil Doppelgänger and Sucksessor; Compare and contrast Job-Stealing Robot, which is about robots and tech in general being competent and cheap enough to run human employees out of the job; there may be overlap. Often overlaps with Deceptively Human Robots and Robot Me.
- Doctor Slump: One chapter has Senbei being invited on a TV show to show one of his inventions. Instead, he sends a robotic version of himself, while he controls the robot from his house. He wins the contest but later he accidentally breaks the machine he used to control the robot, which begins destroying the TV studio and then the entire city.
- Ms. Marvel has Kamala attempt to create replacements so she could superhero without worrying about her real life. It doesnt go well.
- Judge Dredd often has to deal with robotic Judges introduced to the Mega-City-One for whatever reason or crisis. They almost invariably go insane and start shooting everyone.
- Young Justice once got replaced by a team of poorly-made robotic duplicates created by Ivo Jr. Impulse lived with them for a week before he noticed that something was wrong.
- Wonder Woman Vol 1: Professor Menace builds a robotic Wonder Woman meant to replace her, and his plan almost works until he's afraid she'll return from Paradise Island and prevent him from using his robot to commit crime and has it attack her while she's on her way there. She manages to short it out and catch Menace.
- Calvin and Hobbes: In one strip, Calvin is abducted by aliens and replaced with a bad-behaving robot, who proceeds to smash a lamp, raid the cookie jar, dump his textbooks in the garbage can, and more. His parents, of course, don't believe that this is what happened...
- What's New? with Phil and Dixie in Dragon magazine #63. TSR Labs creates a robotic version of Phil Foglio to replace him. The robot shocks Phil and knocks him unconscious for most of the strip. Phil gets his revenge by pouring water in the robot's ear and short circuiting it. In the last panel, just as Phil announces that he and Dixie are finally going to do "Sex and D&D" next month, a robot replacement for Dixie appears (it replaced her offscreen).
- The Santa Clause 2: When Scott is temporarily cast away from the North Pole until he can find a woman to be his wife, a toy Santa is created to take his place. This fake Santa lacked Scott's compassion and boundaries, proclaiming a kid naughty for not doing anything bad at all and places Head Elf Bernard under house arrest.
- Isaac Asimov's "The Tercentenary Incident": Edwards believes that the President was replaced with a robotic duplicate that was involved in a conspiracy to assassinate the President. The trope is Inverted as Janek points out that before the incident, the President had been rather lackluster, but after the incident, they've done a wonderful job, making them a Preferable Impersonator.
- Chernobyl has this, though it's not the fault of the robot. The original plan to clear the stupidly radioactive graphite debris off the roof involved using radiation-hardened robots instead of people, but the final roof, 'Masha', was so radioactive that it outright fried the robot in less than a minute because the Russian government gave the people responsible for providing the robots the "official" radiation figures instead of the actual radiation figures which were tens of times higher, forcing them to resort to humans to clean the debris, although it's unlikely that a robot could be radiation-hardened enough to withstand the actual amount of radiation the graphite was putting out.
- The Mr. Potato Head Show: Zig-Zagged with a robotic duplicate of Mr. Potato Head, built so that the real Mr. Potato Head can go on vacation: at first, the robot is actually well-liked by the cast. However, when they realize the real Mr. Potato Head is miserable because he feels like the robot has made him superfluous, the problems start: the robot concludes the real Mr. Potato Head is a bad influence on the others and tries to keep them from him.
- Star Trek: The Original Series episode "The Ultimate Computer". A computer called the M-5 is installed on the Enterprise to determine if it can replace James Kirk as captain of the ship. M-5 develops artificial intelligence, goes crazy and tries to destroy four other Federation starships.
- In The Addams Family episode "Lurch's Little Helper", Lurch is promoted "head butler" of the house by giving him another butler to order around, "Smiley" (played by Robby the Robot). Smiley proves a poor replacement, leading Lurch to terminate him and go back to being the house's one and only butler.
- The Buffybot from Buffy the Vampire Slayer was built with genuine impersonation of Buffy in mind, but only in a certain context. When the gang tries to use the robot in combat situations and to fool other people, it can generally maintain a halfway decent veneer of normality for a short period of time before screwing it up due to the limits of its programming. Examples include spouting Word Salad instead of snappy one-liners and running away in the middle of a fight because her override tells her to return to Willow for service if she's damaged.
- Katamari Damacy: Katamari Forever sees the King of All Cosmos being knocked into a coma. The Prince and his cousins decide to make a Robotic King to replace him... and said Robotic King destroys the stars. Robotic King does, however, feel bad about it and tries to help The Prince once again rebuild the cosmos.
- PONY.MOV: After Rainbow Dash is sawed in half by Fluttershy, Twilight attempts to use a resurrection spell to bring her back to help take down Discord. When that doesn't work, she decides to build a robot of Rainbow Dash to serve as her replacement. Unfortunately, R-DASH 5000 instead ends up doing the opposite and helps Discord in destroying Ponyville.
- In the 1988 animation Technological Threat, the tyrannical boss of an office takes every possible excuse to replace his workers with obedient robots. Eventually, there's only one worker left, and he looks up to see that even the boss has been replaced. Then the bossbot leaves the office for a moment, and the one remaining living worker starts avenging his colleagues.
- In the SuperMarioLogan episode, "Robot Jeffy", Jackie Chu gives Jeffy detention when he takes a dirty dump in his diaper (or Triple-D'd, as Jeffy calls it) and tosses his diaper at Jackie Chu's face. Because Jeffy doesn't want to go to detention, Cody gets his robot, Codo, to make a robot of Jeffy named Jeffo to take his place. When Bully Bill bullies Jeffo, Jeffo enters Kill Mode and goes on a rampage, leading Codo to destory Jeffo, sacrificing himself in the process.
- Dexter's Laboratory:
- In "Maternal Combat", Dexter makes a robotic version of his mother to replace his mother when she gets sick. It works well until he and Dee Dee fight over the robot's controls, making her go berserk.
- One short has Dexter being asked to repair a damaged Dynomutt, Dog Wonder, but once he succeeds, he deems Dynomutt completely useless because he's a clumsy ditz (even explicitly comparing him to Dee-Dee) and builds an "upgraded" replacement for Blue Falcon. Unfortunately, the replacement Dynomutt is an utterly psychotic Knight Templar that goes on a rampage and nearly kills Dexter and Blue Falcon when they try to stop it.
- The Adventures of Jimmy Neutron: Boy Genius: When Judy goes to a spa getaway, Jimmy creates a "Maternotron" to be her temporary replacement, so that he and his father can get out of doing chores his mother would otherwise be doing. Maternotron however becomes too controlling and strict, such as forcing Carl and Sheen to complete a giant questionnaire to decide whether or not they are allowed to spend time with Jimmy at all.
- An episode of TaleSpin revolved around an attempt by Khan Industries to replace all pilots with a robot, the "Auto-Aviator", and Baloo's fight to not be put out of business. While he was unfortunately unable to beat the Auto-Aviator in a Man Versus Machine competition, the Auto-Aviator showcases a very fatal flaw on in the episode's final act: it is completely unable to change from its preset course and will not accept orders to do so, even when not doing so endangers the plane and everybody in it from being shot down by air pirates.
- One Tom and Jerry episode has Tom being replaced with a robotic mouse-hunting cat in order to better hunt Jerry, and at first it's shown to be efficient. However, later, Jerry discovers and exploits its weakness: toy mice that heavily distracts said robot, causing it to go crazy and wreck the house while trying to hunt them, causing the owner to replace it back with Tom.
- Phineas and Ferb: Phineas and Ferb decide in one episode to create a team of "Phinedroids and Ferbots" to do their creative ideas for them and save time. The robots end up being extremely efficient, doing multiple ideas in a single day and taking the fun out of everything for the boys, then run out of projects and design their own, then go haywire from drinking coffee and attack the boys for trying to shut them down.
- Rick and Morty: In an episode of season three, Rick, Morty, and Summer decide to stay on another planet for a few weeks. In order not to worry Beth, Rick creates robot replacements of all three of them to stay at the house on Earth. The robots do okay other than rather monotone acting, but then the Mortybot starts to become sentient and launches into a rant about being alive in front of Beth. Rickbot and Summerbot intervene, but come off somewhat odd themselves.
Summerbot: We will return... possibly in different clothing.
- Muppet Babies (2018): Beaker 2.0 from his namesake episode was invented by Bunsen to take the real Beaker's place when the latter left to get a haircut. At first, Bunsen enjoys working with Beaker 2.0, but Beaker 2.0 soon turns against Bunsen and kicks him out of Muppet Labs so that he can work on new inventions by himself. As a result, Bunsen needs the real Beaker's help to stop Beaker 2.0.
- In the first episode of the Danger Mouse relaunch series, "Danger Mouse Begins ... Again!", after Danger Mouse accidentally destroys all of London's oddly-shaped glass buildings and wipes out the series budget, he's replaced by robotic Safety Mice created by the supposedly reformed Baron Greenback. Inevitably, it turns out to be an evil plot.