A good trivia question is a small piece of engineering. It has to be hard enough that getting it right feels earned, fair enough that the answer seems obvious the moment it is read out, and interesting enough that the losing table still wants to hear it. Managing all three at once is genuinely difficult, which is why the people who manage it have quietly built a hobby around the craft.

Where the word came from

The Latin trivium meant a meeting of three roads and, by extension, a public place: somewhere ordinary, where anybody at all might be standing. The flavour of the commonplace stuck to the word, and the plural eventually drifted towards knowledge nobody strictly needs. The modern hobbyist sense is surprisingly recent and surprisingly traceable. American students in the mid-1960s began trading questions about advertising jingles, comic strips and radio serials, and a column in the Columbia Daily Spectator attached the label in February 1965. Ed Goodgold and Dan Carlinsky organised the first structured contests and published a book, Trivia, in 1966 that reached the bestseller lists. Obscurity was never the aim. The aim was shared childhood, converted into a scoring system.

The pub quiz, invented slowly

The British pub quiz has a founding story and a much older, messier prehistory behind it. Organised quiz leagues were running across the north-west of England by the late 1950s, with something like four thousand people involved around Merseyside and Lancashire, and the term appears in print from 1959. The modern industry, though, dates from 1976, when Sharon Burns and Tom Porter began arranging quizzes for pubs in the south of England. They started with thirty-two teams across three leagues. Landlords worked out very quickly that a quiz filled the deadest night of the week with customers who stayed three hours and bought drinks between rounds, and the operation grew into thousands of teams.

The format that settled out is unusually well designed for its purpose. Teams write answers down instead of buzzing, so nobody is humiliated in public. Rounds are short, so a terrible start is survivable. A picture round gives the table something to do while scores are totted up, and a music round lets someone who has never opened a history book be the hero for four minutes. Nearly every convention exists to keep a mixed group of friends playing together, which is a quite different design goal from finding out who knows the most.

A game sketched on a cigarette carton

On 15 December 1979, two Canadian journalists, the photo editor Chris Haney and the sports editor Scott Abbott, sat down to play a board game and found that pieces were missing. The often-told version has them deciding, in the way people do, to invent one instead. Trivial Pursuit was reportedly laid out in about three quarters of an hour on the back of a cigarette carton. Researching the questions took most of the following year. The game reached Canadian shops in 1981 and the United States in 1983 under licence to Selchow and Righter, and between 1983 and 1988 the original edition sold in the region of thirty million copies.

It also generated one of the odder pieces of American case law. In October 1984 the trivia author Fred L. Worth sued for $300 million, alleging that a large share of the questions had been taken from his own books, and pointing to a deliberate error he had planted as a trap, a fictitious first name for a famous television detective, which had duly turned up in the game. The courts held that facts are not protected by copyright however much labour goes into gathering them, and the Supreme Court declined to hear the case in 1988. Question-writing, the law decided, is a craft rather than a property.

The serious end

Above the pub sits a competitive layer most people never see. Quiz leagues run on fixtures, tables and promotion much as football does, and the Quiz League of London has been staging interclub matches for decades. There are national championships and a World Quizzing Championship sat simultaneously in dozens of countries on a single day, under exam conditions, with no teams and no conferring. A small population of players treats general knowledge the way a club cyclist treats hills. They keep notebooks. They hold opinions about question style with the intensity a sommelier reserves for glassware.

What makes a question good

Ask a serious setter and the first word you get is discrimination, in the technical sense rather than the social one. A good question separates the field. If everybody gets it, it has told you nothing; if nobody gets it, it has also told you nothing, and it has spent thirty seconds of everyone's evening doing so. The most useful questions sit roughly where a third of the room can reach them.

Fairness is the second axis, and it is where amateur questions most often fail. A fair question can be reasoned towards from what a reasonably informed person already carries about with them. It rewards deduction rather than luck. That is why the good ones tend to be built like a short staircase: an opening clue that means nothing to most of the room, a middle clue that narrows things, and a closing clue that makes the answer inevitable, so the quickest table wins on the first step while everybody else still gets to feel clever by the third.

Then there is the gap between obscure and interesting, which is more or less the whole art. Obscure is the year a minor treaty was signed. Interesting is why it was signed in that particular town. A question is doing its job when the answer produces a noise from the room: the groan of the near miss, the delighted swearing of the person who knew it, the flat astonishment of a fact nobody suspected was true. Setters chase that noise, because it is the only reliable evidence that the question was worth asking in the first place.

The part that is not about knowing things

What actually holds the hobby together is not the answers. It is the table: six people who have tacitly agreed that one of them handles geography, one handles sport, one is inexplicably strong on flags, and one is present for the company and the crisps. Team names are a genre of their own, usually a pun that landed better in the car park. Disputes over a marked answer are conducted with a gravity that would embarrass a parliamentary committee.

Hardly anyone remembers their score by the following week. Everybody remembers the question about the octopus. That is the trick the hobby pulled off: it took the least useful category of knowledge available and turned it into a standing excuse to sit with people for two hours, which may be the most useful thing knowledge has ever managed.