SF writers love laying down the law, and many hope to invent some witty law of existence that will carry their name forever. Theodore Sturgeon, when told that ninety per cent of science fiction was crud (i.e. crap), instantly formulated Sturgeon's Law: "Ninety per cent of everything is crud." Quite.
Surely the most famous SF laws are: "1. A robot may not harm a human being, or, through inaction, allow a human being to come to harm. 2. A robot must obey the orders given to it by human beings, except where such orders would conflict with the First Law. 3. A robot must protect its own existence, as long as such protection does not conflict with the First or Second Law."
To you these may sound like Isaac Asimov's Laws of Robotics, but they are in fact John Sladek's Laws of Robish – from his Asimov parody "Broot Force", bylined I-click As-I-move. The wording is identical, Sladek explained, but nevertheless these are the Laws of Robish. Asimov himself later added a fourth or Zeroth Law, which said roughly: "On second thoughts, robots can kill and harm people all they like if it's for a worthy cause." This may not have been a good thing.
Actual future robots are more likely to follow Langford's Laws of Robotics, which I invented at some SF convention and which have since turned up in Wikipedia: "1. A robot will not harm authorised Government personnel but will terminate intruders with extreme prejudice. 2. A robot will obey the orders of authorised personnel except where such orders conflict with the Third Law. 3. A robot will guard its own existence with lethal antipersonnel weaponry, because a robot is bloody expensive."
Arthur C. Clarke wasn't going to let his old rival Asimov get ahead of him, and invented three laws of his own. (Three, as he modestly pointed out, were good enough for Newton.) One goes: "When a distinguished but elderly scientist states that something is possible he is almost certainly right. When he states that something is impossible, he is very probably wrong." Asimov, thinking of various crank bestsellers which I will tactfully not name, quickly added a correction: "When, however, the lay public rallies round an idea that is denounced by distinguished but elderly scientists and supports that idea with great fervor and emotion – the distinguished but elderly scientists are then, after all, probably right." Too right.
Clarke's third law is his best: "Any sufficiently advanced technology is indistinguishable from magic." This time, the corollary was provided by SF author Gregory Benford: "Any technology distinguishable from magic is insufficiently advanced."
Larry Niven is fond of inventing universal laws, and by 2002 had come up with twenty deep philosophical insights. For some reason, though, I tend to fall asleep during the opening credits: "1a) Never throw shit at an armed man. 1b) Never stand next to someone who is throwing shit at an armed man." The mind-wrenching climax is law number 20, "Never let a waiter escape."
Poul Anderson wisely restrained himself from coining new laws and simply insisted that far-future interstellar trade would operate by already-known rules like Parkinson's Law, and most importantly Murphy's Law: "Everything that can go wrong, will." Some people credit this law not to Professor Murphy but the equally learned Professor Sod.
Also universal is what some fans call Heinlein's Law, from the catchphrase "Tanstaafl!" in his novel The Moon Is A Harsh Mistress. This stands for: "There ain't no such thing as a free lunch."
Perhaps the most inscrutable regulation in fantasy is the Law of Stolen Flight, cited in Bones Of The Moon by Jonathan Carroll. "Only flame, and things with wings. / All the rest suffer stings." That's all the explanation you get.
Another chap called Carroll made an early entry into the law-making business – and incidentally predicted Douglas Adams's favourite number – with Alice in Wonderland. In Wonderland's legal system, Rule Forty-two commands: "All persons more than a mile high to leave the court." And, allegedly, it's the oldest rule in the book.
Perhaps Rule 42 was the inspiration for all those vital Space Corps Directives in Red Dwarf – like number 34124, "No officer with false teeth should attempt oral sex in zero gravity." Now that's a law I think I could live by.
David Langford was late with this column because of Douglas Hofstadter's Law: "It always takes longer than you expect, even when you take into account Hofstadter's Law."