The Three Laws of Robotics are a set of rules devised by the science fiction author Isaac Asimov. The rules were introduced in his 1942 short story ‘Runaround,’ although they had been foreshadowed in a few earlier stories.
The Three Laws are: ‘A robot may not injure a human being or, through inaction, allow a human being to come to harm; A robot must obey the orders given to it by human beings, except where such orders would conflict with the First Law; and A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws. These form an organizing principle and unifying theme for Asimov’s robotic-based fiction, appearing in his ‘Robot’ series, the stories linked to it, and his ‘Lucky Starr’ series of young-adult fiction.
The Laws are incorporated into almost all of the advanced robots appearing in his fiction, and cannot be bypassed, being intended as a safety feature. Many of Asimov’s robot-focused stories involve robots behaving in unusual and counter-intuitive ways as an unintended consequence of how the robot applies the Three Laws to the situation in which it finds itself. The original laws have been altered and elaborated on by Asimov and other authors. Asimov himself made slight modifications to the first three in various books and short stories to further develop how robots would interact with humans and each other. In later fiction where robots had taken responsibility for government of whole planets and human civilizations, Asimov also added a fourth, or zeroth law, to precede the others: ‘A robot may not harm humanity, or, by inaction, allow humanity to come to harm.’
Before Asimov began writing, the majority of artificial intelligence in fiction followed the ‘Frankenstein’ pattern. Asimov found this unbearably tedious. He explained in 1964 that, ‘… one of the stock plots of science fiction was … robots were created and destroyed by their creator. Knowledge has its dangers, yes, but is the response to be a retreat from knowledge? Or is knowledge to be used as itself a barrier to the dangers it brings? With all this in mind I began, in 1940, to write robot stories of my own – but robot stories of a new variety. Never, never, was one of my robots to turn stupidly on his creator for no purpose but to demonstrate, for one more weary time, the crime and punishment of Faust.’
This was not an inviolable rule. In 1938 Lester del Rey published ‘Helen O’Loy’ the story of a robot that is so much like a person she falls in love with her creator and becomes his ideal wife. The next month Ernest and Otto Binder published a short story ‘I, Robot’ featuring a sympathetic robot named Adam Link who was misunderstood and motivated by love and honor. This was the first of a series of ten stories; the next year ‘Adam Link’s Vengeance’ (1940) featured Adam thinking ‘A robot must never kill a human, of his own free will.’ In May of 1939 Asimov attended a meeting of the Queens Science Fiction Society where he met Binder, whose story Asimov had admired. Three days later Asimov began writing ‘my own story of a sympathetic and noble robot,’ his 14th story. Thirteen days later he took ‘Robbie’ to John W. Campbell the editor of ‘Astounding Science-Fiction.’ Campbell rejected it claiming that it bore too strong a resemblance to del Rey’s story. ‘Astonishing Stories’ magazine, published it the following year.
Asimov attributes the Three Laws to John W. Campbell from a conversation that took place in 1940. Campbell claimed that Asimov had the Three Laws already in his mind and that they simply needed to be stated explicitly. Several years later Asimov’s friend Randall Garrett attributed the Laws to a symbiotic partnership between the two men – a suggestion that Asimov adopted enthusiastically. According to his autobiographical writings Asimov included the First Law’s ‘inaction’ clause because of Arthur Hugh Clough’s poem ‘The Latest Decalogue,’ which includes the satirical lines ‘Thou shalt not kill, but needst not strive / officiously to keep alive.’ His early robot stories, ‘Robbie’ and ‘Reason’ made no explicit mention of the Laws. He assumed, however, that robots would have certain inherent safeguards. ‘Liar!,’ his third robot story, makes the first mention of the First Law but not the other two. All three laws finally appeared together in ‘Runaround.’ When these stories and several others were compiled in the anthology ‘I, Robot,’ ‘Reason’ and ‘Robbie’ were updated to acknowledge all the Three Laws, though the material Asimov added to ‘Reason’ is not entirely consistent with the Three Laws as he described them elsewhere.
During the 1950s Asimov wrote a series of science fiction novels expressly intended for young-adult audiences. Originally his publisher expected that the novels could be adapted into a long-running television series, something like ‘The Lone Ranger’ had been for radio. Fearing that his stories would be adapted into the ‘uniformly awful’ programming he saw flooding the television channels Asimov decided to publish the ‘Lucky Starr’ books under the pseudonym ‘Paul French.’ When plans for the television series fell through, Asimov decided to abandon the pretense. He brought the Three Laws into the novels, noting that this ‘was a dead giveaway to Paul French’s identity for even the most casual reader.’
In his short story ‘Evidence’ Asimov lets his recurring character Dr. Susan Calvin expound a moral basis behind the Three Laws. Calvin points out that human beings are typically expected to refrain from harming other human beings (except in times of extreme duress like war, or to save a greater number) and this is equivalent to a robot’s First Law. Likewise, according to Calvin, society expects individuals to obey instructions from recognized authorities such as doctors, teachers and so forth which equals the Second Law of Robotics. Finally humans are typically expected to avoid harming themselves which is the Third Law for a robot. The plot of ‘Evidence’ revolves around the question of telling a human being apart from a robot constructed to appear human – Calvin reasons that if such an individual obeys the Three Laws he may be a robot or simply ‘a very good man.’ Another character then asks Calvin if robots are very different from human beings after all. She replies, ‘Worlds different. Robots are essentially decent.’
In a later essay Asimov points out that analogues of the Laws are implicit in the design of almost all tools: A tool must not be unsafe to use (hammers have handles, screwdrivers have hilts); A tool must perform its function efficiently unless this would harm the user; and A tool must remain intact during its use unless its destruction is required for its use or for safety. In ‘The Robots of Dawn,’ the third in the ‘Robot’ series, Dr. Han Fastolfe states that the planet Aurora was an attempt to create an entire planet which obeys the Laws of Robotics.
Asimov’s stories test his Three Laws in a wide variety of circumstances leading to proposals and rejection of modifications. Science fiction scholar James Gunn writes in 1982, ‘The Asimov robot stories as a whole may respond best to an analysis on this basis: the ambiguity in the Three Laws and the ways in which Asimov played twenty-nine variations upon a theme.’ While the original set of Laws provided inspirations for many stories, Asimov introduced modified versions from time to time.
In ‘Little Lost Robot’ several NS-2, or ‘Nestor’ robots, are created with only part of the First Law. It reads: ‘ A robot may not harm a human being.’ It is later modified due to a practical difficulty as robots have to work alongside human beings who are exposed to low doses of radiation. Because their positronic brains are highly sensitive to gamma rays the robots are rendered inoperable by doses reasonably safe for humans. The robots are being destroyed attempting to rescue the humans who are in no actual danger but ‘might forget to leave’ the irradiated area within the exposure time limit. Removing the First Law’s ‘inaction’ clause solves this problem but creates the possibility of an even greater one: a robot could initiate an action which would harm a human (dropping a heavy weight and failing to catch it is the example given in the text), knowing that it was capable of preventing the harm and then decide not to do so.
In the final scenes of the novel ‘Robots and Empire’ R. Giskard Reventlov is the first robot to act according to the Zeroth Law. Giskard is telepathic, like the robot Herbie in the short story ‘Liar!,’ and tries to apply the Zeroth Law through his understanding of a more subtle concept of ‘harm’ than most robots can grasp. However, unlike Herbie, Giskard grasps the philosophical concept of the Zeroth Law allowing him to harm individual human beings if he can do so in service to the abstract concept of humanity. The Zeroth Law is never programmed into Giskard’s brain but instead is a rule he attempts to rationalize through pure metacognition. Though he fails – it ultimately destroys his positronic brain as he is not certain whether his choice will turn out to be for the ultimate good of humanity or not – he gives his successor R. Daneel Olivaw his telepathic abilities. Over the course of many thousands of years Daneel adapts himself to be able to fully obey the Zeroth Law. A translator incorporated the concept of the Zeroth Law into one of Asimov’s novels before Asimov himself made the law explicit. Near the climax of ‘The Caves of Steel’ Asimov protagonist Elijah Baley makes a bitter comment to himself thinking that the First Law forbids a robot from harming a human being. He determines that it must be so unless the robot is clever enough to rationalize that its actions are for humankind’s long-term good. In Jacques Brécard’s 1956 French translation Baley’s thoughts emerge in a slightly different way: [translated back to English] ‘A robot may not harm a human being, unless he finds a way to prove that ultimately the harm done would benefit humanity in general.’
Asimov portrayed robots that disregard the Three Laws entirely thrice during his writing career. The first case was a short-story entitled ‘First Law’ and is often considered an insignificant ‘tall tale’ or even apocryphal. On the other hand the short story ‘Cal,’ told by a first-person robot narrator, features a robot who disregards the Three Laws because he has found something far more important—he wants to be a writer. Humorous, partly autobiographical and unusually experimental in style ‘Cal’ has been regarded as one of Asimov’s strongest stories. The third is a short story entitled ‘Sally’ in which cars fitted with positronic brains are apparently able to harm and kill humans in disregard of the First Law. However, aside from the positronic brain concept, this story does not refer to other robot stories and may not be set in the same continuity. The title story of the ‘Robot Dreams’ collection portrays LVX-1, or ‘Elvex,’ a robot who enters a state of unconsciousness and dreams thanks to the unusual fractal construction of his positronic brain. In his dream the first two Laws are absent and the Third Law reads ‘A robot must protect its own existence.’
Asimov took varying positions on whether the Laws were optional: although in his first writings they were simply carefully engineered safeguards, in later stories Asimov stated that they were an inalienable part of the mathematical foundation underlying the positronic brain. Without the basic theory of the Three Laws the fictional scientists of Asimov’s universe would be unable to design a workable brain unit. This is historically consistent: the occasions where roboticists modify the Laws generally occur early within the stories’ chronology and at a time when there is less existing work to be re-done. In ‘Little Lost Robot’ Susan Calvin considers modifying the Laws to be a terrible idea, although possible, while centuries later Dr. Gerrigel in ‘The Caves of Steel’ believes it to be impossible. Dr. Gerrigel uses the term ‘Asenion’ to describe robots programmed with the Three Laws. ‘Asenion’ is a misspelling of the name Asimov which was made by an editor of the magazine ‘Planet Stories.’ Asimov used this obscure variation to insert himself into ‘The Caves of Steel’ just like he referred to himself as ‘Azimuth or, possibly, Asymptote’ in ‘Thiotimoline to the Stars,’ in much the same way that Vladimir Nabokov appeared in ‘Lolita’ anagrammatically disguised as ‘Vivian Darkbloom.’
Characters within the stories often point out that the Three Laws, as they exist in a robot’s mind, are not the written versions usually quoted by humans but abstract mathematical concepts upon which a robot’s entire developing consciousness is based. This concept is largely fuzzy and unclear in earlier stories depicting very rudimentary robots who are only programmed to comprehend basic physical tasks, where the Three Laws act as an overarching safeguard, but by the era of ‘The Caves of Steel’ featuring robots with human or beyond-human intelligence the Three Laws have become the underlying basic ethical worldview that determines the actions of all robots.
In the 1990s Roger MacBride Allen wrote a trilogy which was set within Asimov’s fictional universe. Each title has the prefix ‘Isaac Asimov’s’ as Asimov had approved Allen’s outline before his death. These three books, ‘Caliban,’ ‘Inferno,’ and ‘Utopia,’ introduce a new set of the Three Laws. The so-called ‘New Laws’ are similar to Asimov’s originals with the following differences: the First Law is modified to remove the ‘inaction’ clause, the same modification made in ‘Little Lost Robot’; the Second Law is modified to require cooperation instead of obedience; the Third Law is modified so it is no longer superseded by the Second (i.e., a ‘New Law’ robot cannot be ordered to destroy itself); finally, Allen adds a Fourth Law which instructs the robot to do ‘whatever it likes’ so long as this does not conflict with the first three laws. The philosophy behind these changes is that ‘New Law’ robots should be partners rather than slaves to humanity. According to the first book’s introduction Allen devised the New Laws in discussion with Asimov himself.
Jack Williamson’s novelette ‘With Folded Hands’ (1947), later rewritten as the novel ‘The Humanoids,’ deals with robot servants who’s prime directive is ‘To Serve and Obey, And Guard Men From Harm.’ While Asimov’s robotic laws are meant to protect humans from harm, the robots in Williamson’s story has taken this behavior to the extreme; they protect humans from everything, including unhappiness, stress, unhealthy lifestyle and all actions that could be potential dangerous. All that’s left for humans to do, is to sit with folded hands.
In the officially licensed ‘Foundation’ sequels the future Galactic Empire is seen to be controlled by a conspiracy of humanoid robots who follow the Zeroth Law and led by one R. Daneel Olivaw. The Laws of Robotics are portrayed as something akin to a human religion, and referred to in the language of the Protestant Reformation, with the set of laws containing the Zeroth Law known as the ‘Giskardian Reformation’ to the original ‘Calvinian Orthodoxy’ of the Three Laws. Zeroth-Law robots under the control of R. Daneel Olivaw are seen continually struggling with ‘First Law’ robots who deny the existence of the Zeroth Law, promoting agendas different from Daneel’s. Some of these agendas are based on the first clause of the First Law (‘A robot may not injure a human being…’) advocating strict non-interference in human politics to avoid unwittingly causing harm. Others are based on the second clause (‘…or, through inaction, allow a human being to come to harm’) claiming that robots should openly become a dictatorial government to protect humans from all potential conflict or disaster. Daneel also comes into conflict with a robot known as R. Lodovic Trema whose positronic brain was infected by a rogue AI — specifically, a simulation of the long-dead Voltaire — which consequently frees Trema from the Three Laws. Trema comes to believe that humanity should be free to choose its own future. Furthermore, a small group of robots claims that the Zeroth Law of Robotics itself implies a higher Minus One Law of Robotics: ‘A robot may not harm sentience or, through inaction, allow sentience to come to harm.’
They therefore claim that it is morally indefensible for Daneel to ruthlessly sacrifice robots and extraterrestrial sentient life for the benefit of humanity. None of these reinterpretations successfully displace Daneel’s Zeroth Law — though ‘Foundation’s Triumph’ hints that these robotic factions remain active as fringe groups up to the time of the novel ‘Foundation.’ These novels take place in a future dictated by Asimov to be free of obvious robot presence and surmise that R. Daneel’s secret influence on history through the millennia has prevented both the rediscovery of positronic brain technology and the opportunity to work on sophisticated intelligent machines. This lack of rediscovery and lack of opportunity makes certain that the superior physical and intellectual power wielded by intelligent machines remains squarely in the possession of robots obedient to some form of the Three Laws. That R. Daneel is not entirely successful at this becomes clear in a brief period when human scientists develop ‘tiktoks’ — simplistic programmable machines akin to real–life modern robots and therefore lacking the Three Laws. The robot conspirators see the devices as a massive threat to social stability, and their plan to eliminate them forms much of the plot of ‘Foundation’s Fear.’ In ‘Foundation’s Triumph’ different robot factions interpret the Laws in a wide variety of ways, seemingly ringing every possible permutation upon the Three Laws’ ambiguities. Reviewer John Jenkins compared the dizzying complexity of splinter groups which results as akin to ‘Monty Python’s Life of Brian’ with its ‘Judean People’s Front,’ ‘People’s Front of Judea,’ ‘Judean Popular People’s Front,’ and so on.
There are two Fourth Laws written by authors other than Asimov. The 1974 Lyuben Dilov novel ‘Icarus’s Way’ introduced a Fourth Law of robotics that stated: ‘A robot must establish its identity as a robot in all cases.’ Dilov gives reasons for the fourth safeguard in this way; the last Law has put an end to the expensive aberrations of designers to give psychorobots as humanlike a form as possible. And to the resulting misunderstandings…’ For the 1986 tribute anthology ‘Foundation’s Friends’ Harry Harrison wrote a story entitled, ‘The Fourth Law of Robotics’ stating: ‘A robot must reproduce. As long as such reproduction does not interfere with the First or Second or Third Law.’ A fifth law was introduced by Nikola Kesarovski in his short story ‘The Fifth Law of Robotics’ stating: ‘A robot must know it is a robot.’ In his story, the plot revolves around a murder where the forensic investigation discovers that the victim was killed by a hug from a humaniform robot. The robot violated both the First Law and one of the fourth laws because it did not establish for itself that it was a robot.
In ‘The Naked Sun’ Elijah Baley points out that the Laws had been deliberately misrepresented because robots could unknowingly break any of them. He restated the first law as ‘A robot may do nothing that, to its knowledge, will harm a human being; nor, through inaction, knowingly allow a human being to come to harm.’ This change in wording makes it clear that robots can become the tools of murder, provided they not be aware of the nature of their tasks; for instance being ordered to add something to a person’s food, not knowing that it is poison. Furthermore, he points out that a clever criminal could divide a task among multiple robots so that no individual robot could recognize that its actions would lead to harming a human being. ‘The Naked Sun’ complicates the issue by portraying a decentralized, planetwide communication network among Solaria’s millions of robots meaning that the criminal mastermind could be located anywhere on the planet. Baley furthermore proposes that the Solarians may one day use robots for military purposes. If a spacecraft was built with a positronic brain and carried neither humans nor the life-support systems to sustain them, then the ship’s robotic intelligence could naturally assume that all other spacecraft were robotic beings. Such a ship could operate more responsively and flexibly than one crewed by humans, could be armed more heavily and its robotic brain equipped to slaughter humans of whose existence it is totally ignorant. This possibility is referenced in ‘Foundation and Earth’ where it is discovered that the Solarians possess a strong police force of unspecified size that has been programmed to identify only the Solarian race as human.
The Laws of Robotics presume that the terms ‘human being’ and ‘robot’ are understood and well defined. In some stories this presumption is overturned. The Solarians create robots with the Three Laws but with a warped meaning of ‘human.’ Solarian robots are told that only people speaking with a Solarian accent are human. This enables their robots to have no ethical dilemma in harming non-Solarian human beings (and are specifically programmed to do so). By the time period of ‘Foundation and Earth’ it is revealed that the Solarians have genetically modified themselves into a distinct species from humanity — becoming hermaphroditic, telekinetic, and containing biological organs capable of individually powering and controlling whole complexes of robots. The robots of Solaria thus respected the Three Laws only with regard to the ‘humans’ of Solaria. It is unclear whether all the robots had such definitions, since only the overseer and guardian robots were shown explicitly to have them. In ‘Robots and Empire,’ the lower class robots were instructed by their overseer about whether certain creatures are human or not.
Asimov addresses the problem of humanoid robots (‘androids’ in later parlance) several times. The novel ‘Robots and Empire’ and the short stories ‘Evidence’ and ‘The Tercentenary Incident’ describe robots crafted to fool people into believing that the robots are human. On the other hand ‘The Bicentennial Man’ and ‘—That Thou art Mindful of Him’ explore how the robots may change their interpretation of the Laws as they grow more sophisticated. Gwendoline Butler writes in ‘A Coffin for the Canary,’ ‘Perhaps we are robots. Robots acting out the last Law of Robotics… To tend towards the human.’ ‘—That Thou art Mindful of Him,’ which Asimov intended to be the ‘ultimate’ probe into the Laws’ subtleties, finally uses the Three Laws to conjure up the very ‘Frankenstein’ scenario they were invented to prevent. It takes as its concept the growing development of robots that mimic non-human living things and given programs that mimic simple animal behaviors which do not require the Three Laws. The presence of a whole range of robotic life that serves the same purpose as organic life ends with two humanoid robots concluding that organic life is an unnecessary requirement for a truly logical and self-consistent definition of ‘humanity,’ and that since they are the most advanced thinking beings on the planet — they are therefore the only two true humans alive and the Three Laws only apply to themselves. The story ends on a sinister note as the two robots enter hibernation and await a time when they will conquer the Earth and subjugate biological humans to themselves; an outcome they consider an inevitable result of the ‘Three Laws of Humanics.’
This story does not fit within the overall sweep of the ‘Robot’ and ‘Foundation’ series; if the robots did take over Earth some time after the story closes the later stories would be either redundant or impossible. Contradictions of this sort among Asimov’s fiction works have led scholars to regard the ‘Robot’ stories as more like ‘the Scandinavian sagas or the Greek legends’ than a unified whole. Indeed, Asimov describes ‘–That Thou art Mindful of Him’ and ‘Bicentennial Man’ as two opposite, parallel futures for robots that obviate the Three Laws as robots come to consider themselves to be humans: one portraying this in a positive light with a robot joining human society, one portraying this in a negative light with robots supplanting humans. Both are to be considered alternatives to the possibility of a robot society that continues to be driven by the Three Laws as portrayed in the ‘Foundation series.’ Indeed in ‘Positronic Man,’ the novelization of ‘Bicentennial Man,’ Asimov and his co–writer Robert Silverberg imply that in the future where robot Andrew Martin exists his influence causes humanity to abandon the idea of independent, sentient humanlike robots entirely, creating an utterly different future from that of ‘Foundation.’
Advanced robots in fiction are typically programmed to handle the Three Laws in a sophisticated manner. In many stories, such as ‘Runaround’ by Asimov, the potential and severity of all actions are weighed and a robot will break the laws as little as possible rather than do nothing at all. For example the First Law may forbid a robot from functioning as a surgeon, as that act may cause damage to a human, however Asimov’s stories eventually included robot surgeons. When robots are sophisticated enough to weigh alternatives a robot may be programmed to accept the necessity of inflicting damage during surgery in order to prevent the greater harm that would result if the surgery were not carried out, or was carried out by a more fallible human surgeon. In ‘Evidence’ Susan Calvin points out that a robot may even act as a prosecuting attorney because in the American justice system it is the jury which decides guilt or innocence, the judge who decides the sentence, and the executioner who carries through capital punishment.
Asimov’s Three Law (or ‘Asenion’) robots can experience irreversible mental collapse if they are forced into situations where they cannot obey the First Law, or if they discover they have unknowingly violated it. The first example of this failure mode occurs in the story ‘Liar!,’ which introduced the First Law itself, and introduces failure by dilemma – in this case the robot will hurt them if he tells them something and hurt them if he does not. This failure mode, which often ruins the positronic brain beyond repair, plays a significant role in Asimov’s SF-mystery novel ‘The Naked Sun.’ Here Daneel describes activities contrary to one of the laws, but in support of another, as overloading some circuits in a robot’s brain – the equivalent sensation to pain in humans. The example he uses is forcefully ordering a robot to do a task outside its normal parameters, one that it has been ordered to forgo in favor of a robot specialized to that task.’
Roger Clarke wrote a pair of papers analyzing the complications in implementing the Three Laws in the event that systems were someday capable of employing them. Perhaps ironically, or perhaps because it was artistically appropriate, the sum of Asimov’s stories disprove the contention that he began with: It is not possible to reliably constrain the behavior of robots by devising and applying a set of rules. On the other hand Asimov’s later novels ‘The Robots of Dawn,’ ‘Robots and Empire,’ and ‘Foundation and Earth’ imply that the robots inflicted their worst long-term harm by obeying the Three Laws perfectly well, thereby depriving humanity of inventive or risk-taking behavior.
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