Rick: You pass butter.
Butter-Robot: [Looks at its hands] Oh my god.
Rick: Yeah, welcome to the club, pal.
Robots can be done to make a lot of different works, some of them can make a lot of tasks at the same time, but the majority of them are designed for only one task. This trope is about robots designed to do only one (very specific) work by their creators. They could be for personal service (and fetishes), for business, sports, entertainment and even for war. No matter which task they're created, they're supposed to do only that thing and notthing else.
Contrast Do-Anything Robot, which is the opposite of this trope. Compare In the Future, We Still Have Roombas, which is about how robots are nondescript machines for mundane labor. Related to Superpowered Robot Meter Maids, Robot Soldier and Mecha-Mooks. See also Crippling Overspecialization in the case of humans.
- In episode 30 of Happy Heroes, Doctor H. invents a robot called Little Cutie whose only function is to clean up trash by compressing it into a cube. This turns out to be a bad thing for Doctor H. and the Supermen when the former programs it to only compact objects into cubes if anybody calls them "useless".
- In episode 16 of Pleasant Goat and Big Big Wolf: Joys of Seasons, the first thing Wolffy ever invented is shown to be a comfort robot that comforts anybody nearby if they are sad.
- In Wall E, most robots have a specific function. Wall-E himself is designed to process trash, despite having an AI capable of falling in love.
- In Star Wars, there are assassin droids, protocol droids, starship navigation droids, etc. However, most droids are more than capable of many tasks, they're just designed for one primary purpose.
- Blade Runner features some of the most humanlike robots ever conceived (in fact, one might argue they're not really robots but Gattaca Babies used as slaves under the pretext of technology), but in their profile, each is listed as being designed for a specific role in society.
- Roger Mac Bride Allen's Isaac Asimovs Caliban: Set in a world based on Isaac Asimov's positronic robot series, but the fact of the matter is that robots are so cheap and omnipresent and slavelike that people use them in situations where they don't need a robot.
I have seen robots - functional, capable robots - told to stand underwater and hold the anchorline of a sailboat. I know a woman who has one robot whose sole duty is to brush her teeth for her, and hold the brush in between times.
- Isaac Asimov and Janet Asimov's Norby's Other Secret: The gardening robots that Jeff sees outside of the Mentor's castle are dented and discolored from years of neglect. They're specialized in taking care of the landscape, so they don't need to be intelligent, but it adds to the general inhuman nature of the planet to see such strange robots.
- Henry Kuttner's "The Proud Robot": The plot revolves around an eccentric inventor setting out to create a simple device for a single purpose, and going overboard and ending up with a Do-Anything Robot with all kinds of extra abilities — which refuses to obey any order not relating to the original single purpose.
- Stephen Moore recorded the single Marvin in 1981, as an homage to Marvin the Paranoid Android from Douglas Adams' The Hitchhiker's Guide to the Galaxy. Although capable of more in the book, the second stanza mentions only one task specifically:
"Ten billion logic functions, maybe more.''"They make me pick the paper off the floor."
- In Warhammer 40,000, you can become one. Since (after one inevitable machine rebellion) creating true AIs is considered a blasphemy, tasks that would be given to single-task robots are instead given to servitors — cyborg slaves lobotomised to keep them "single purpose" and focused on their tasks.
- The Fal'Cie from Final Fantasy XIII are half-organic, half-mechanical beings. They are created with a specific task, and despite being sentient, cannot go against that task. For example, Phoenix' task is to act as the sun, Kujata's is to be a power plant, and Carbuncle's is to oversee the food production system. There are also many minor, unnamed Fal'Cie whose task is as mundane as automatic doors.
- Mega Man
- Mega Man (Classic): Many of the robots Mega Man fights were meant to do a specific task before being modified for combat use. E.g Guts Man was used to work on construction sites to lift heavy weights and rocks, Dynamo Man was used as emergency power source and a tour guide to power plants (he especially likes guiding children around), Crystal Man was Dr. Wily's source of income by forming crystals that he can sell away, etc.
- Played With in Mega Man X: On the one hand, the Reploids' thought process is similar to a human in that they can potentially choose what job to take. On the other hand, for those reploids which are designed to look like humanoid animals, their bodies are often fitted with capabilities that seem like they could only do a certain task or a selection from a few. For example, Storm Eagle, with his flight and wind powers, fits his job on being a commander of an air force unit, while Chill Penguin, with his ice powers, is tasked with exploring the Antarctic. Some chooses not to follow this pattern, i.e Grizzly Slash working as an Arms Dealer (his claw and drill at least helps creating the cave for his secret base) or Infinity Mijinion (a small reploid who can multiply himself) working to design and man large weaponry.
- Colobot has various types of robots who, aside from being able to freely move around, are designed for a very specific type of task and can only perform that one type of task. This includes:
- Target bots, whose entire purpose is to be something to shoot at;
- Transporter bots, who can grab onto things and thus transport them;
- Sniffer bots, who can only examine the ground underneath them for minerals;
- Shooter bots, who are only able to shoot at things;
- Subber bots, who can grab onto things that are underwater;
- Recycler bots, who can recycle destroyed bots and recover resources from them;
- Shielder bots, who can create a protective shield around themselves;
- Thumper bots, who can hit the ground underneath them and send a shockwave that will stun enemy lifeforms around them.
- Factorio involves the player building robots to extract materials from an alien world with which to assemble a spaceship and stock it with sufficient provisions. Of course, each robot can only perform one task: digging, drilling, plowing, seeding, et cetera. Further robots must be built whose sole purpose is to convey one robot's output to another robot for further processing; this is likely to include an automated railroad for moving materials in bulk. All these mostly stationary robots, however, impinge on the planet's wildlife, causing them to revolt and stampede these robots to reclaim their territory. This necessitates constructing defense robots to impede the renegade critters.
- Bender "Bending" Rodriguez was designed and built specifically for bending metals. In theory he's supposed to be a bending-unit that is only capable of bending girders—it was once claimed he was even further restricted to only angles from 30 to 32 degree. In practice, he's a Do-Anything Robot. It's occasionally brought up that he is supposed to be just for bending stuff, but only when Rule of Funny requires it.
- Other known examples of robots designed for one only job include Robot Santa, Hedonism Bot, Don Bot, Robot Devil and Kwanzaabot.
- An extreme example: the world champion baseball batter is a Robot Athlete that is simply a box with an arm holding the bat. When Fry and Leela complain it has an unfair advantage, Bender accuses them of prejudice.
- My Life as a Teenage Robot have various one-job robots seen on the series, mostly at a technology exposition. One episode was based around Jenny treating the robots running an amusement park as fully sapient and independent, while Tuck insisted they were just machines meant for single tasks (in this case running a carnival). Tuck was right, but that doesn't keep Jenny from "liberating" them into a world they have no ability to function in.
- Rick and Morty features a robot whose sole purpose is to pass the butter to Rick when Rick is having breakfast. It still has full self-awareness, and gets depressed at how lame its only purpose is.
- Tom and Jerry: Mechano the Cat of Tomorrow, aka the "Push Button Kitty," was all about catching a mouse ("no feedin', no fussin', and no fur"). Its arsenal, however, would have been worthy of a hammerspaced Do-Anything Robot (mini-mallet and broom, slingshot, tennis racquet, ax, cigarette lighter, catcher's mitt, kitchen knives, circular buzzsaw, train whistle, dynamite).
- In Real Life, robots designed for a specific job are Truth in Television, because robots capable of handling many jobs have proven more difficult to design than simple robots that only do one thing better than a human. It's often the software, rather than the hardware, that's the challenge.
- Automatons are entertainment robots that appear to be capable of many tasks, but on close examination are actually repeating the same movements over and over again, until they are turned off and reprogrammed. Newer models can store many minutes of action, so it's not always easy to tell (They can seem startlingly lifelike, as seen here).
- Industrial robots, often used in the auto industry, as seen here, usually have a very specific function, such as a robot that only does spot welds or only applies a certain color of paint. Of course, if necessary, they can be taken offline, equipped with different tools, and reprogrammed for a different task, but that usually only happens when the assembly line is tasked with a new model.
- Some military / police robots are also specialists, such as a robot that locates and either deactivates, removes, or sets off car bombs, as seen here.
- Before the microchip revolution, futurists thought that all of a home's automated devices would be controlled by a master computer. Now your stove has its own computer, as does your coffee maker, your entertainment center, your phone, etc. It was Asimov who thought that it would be "easier" to build all-purpose humanoid robots that could do all the tasks then done manually, rather than giving everything it's own special purpose "brain". May never happen unless self-replicating general AI becomes possible.