When you’re thinking of the Theatre of the Absurd, life tends to copy art. Douglas Hodge, who is staging a triple bill called Absurdia at the Donmar Warehouse in London, found himself earnestly asking friends who were charitably adopting a whale: “Where are you going to put it?” I was talking to Michael Grandage, the Donmar’s artistic director, when he said, “And the truth of the matter is . . .” and went into a learned disquisition about Absurdism, which was a complete blank to me since his mobile had cut out.

Then, after the PR people had spent a day hunting down the 88-year-old N. F. Simpson, who had apparently evaporated somewhere in London, my trusty tape recorder failed to record what he said about A Resounding Tinkle and Gladly Otherwise, the playlets he has contributed to Absurdia. And then, bless me, it did the same with Michael Frayn, whose new Crimson Hotel completes the evening. I could hear myself chuckling and saying “terrific” on the tape but there was total silence from them. So in the spirit of the absurd, don’t believe a word of this piece. It comes from my scrambled notes and addled brain.

Beckett excepted, we haven’t seen much of the Theatre of the Absurd since its heyday in the 1960s. That’s why Grandage has long wanted to find out whether the genre still has legs, first planning a festival of absurdist writers, then reducing this to a pairing of Englishmen. And others are catching the bug, for the Royal Shakespeare Company has just staged Macbett, Ionesco’s Shakespeare parody, and last week there was a rehearsed reading of Simpson’s unknown If So Then Yes at the Royal Court, the theatre that will revive Ionesco’s Rhinoceros in the autumn. Perhaps another heyday is in the offing.

So what is Absurdism? Ionesco explained that his plays derived from childhood, when the sight of Punch and Judy left him feeling that he was watching “the spectacle of the world itself – unusual, improbable, grotesque, but truer than truth”.

Simpson said that his plays could be “readily understood by anyone who has ever been threaded through the top of someone’s pyjama trousers and found himself protruding from both ends at once”; but, like Frayn, he isn’t sure that the label Theatre of the Absurd fits his work.

Certainly, so-called Absurdism is various. Simpson’s One Way Pendulum: a traffic warden tries to teach 500 speak-your-weight machines to sing the Hallelujah Chorus. Beckett’s Happy Days: a housewife cheerily babbles away while she’s buried in sand. Ionesco’s Rhinoceros: small-town people are serially transformed into rampaging beasts. So one might go on, citing Wolfgang Hildesheimer, Dino Buzzati, Ezio D’Erico and other names so abstruse that they might have been invented by those Johnny-come-latelies, the Monty Python boys.

Actually, they’re some of many dramatists cited by the late Martin Esslin in his Theatre of the Absurd, the book that gave a name to what he saw as a genre or school. This he derived from Camus, who had written in his Myth of Sisyphus that modern man had become a baffled stranger in a world “deprived of illusions and light” and so was overwhelmed by “a feeling of absurdity”. Esslin traced the genre back to the Dadaist Tzara, who in 1921 wrote a play about talking noses and eyebrows, and to Jarry’s 1896 caricature of a tyrant, Ubu Roi; but he felt that Absurdism suited the socially shifting, spiritually confused world of 1961, when his book appeared.

At times one feels that the word “absurd” covers so many different writers – Pinter and Albee make guest appearances in Esslin’s book – as to be absurd itself. But it’s possible to pick out two distinct manifestations of the genre, though they often overlap. The one, says Frayn, “places some extraordinary event into the context of ordinary life and treats it as if it’s absolutely normal”. The result is often a play that jokily exposes the shallowness, idiocy and arbitrary values of society. The other is more metaphysical. “If you have no faith and don’t believe in God there’s no reason for living,” explains Hodge. “You just sit and exist and your situation becomes absurd. The English,” he goes on, “find this rather hilarious but the Europeans see it as desolate.”

An example of Absurdity No 1 would be Ionesco’s first play, The Bald Prima Donna, a sly attack on the bourgeoisie in which Mr Smith exchanges the banalities the author found in a French-English phrase-book (“the country is larger than the city”) with a woman he doesn’t recognise as Mrs Smith. Another is A Resounding Tinkle, where a suburban couple debate the name of the elephant that has just been delivered to them. Simpson describes this as a “jeu d’esprit” influenced more by The Goon Show than by Ionesco, whom he’d never heard of when he wrote it in 1957. But although he now disclaims any didactic intent (“I’m not a ruddy missionary”), he did once say that he hoped to inoculate audiences with a mild strain of lunacy to give them resistance against its worst form – sanity.

He also remarked that he believed in God “because who else could have boobed on that kind of scale?” There, he’s closer to those Paris-based agnostics, the Romanian Ionesco and the Irish Beckett, whose Hamm in Endgame thinks God a “b******” for refusing to exist. That play and Waiting for Godot are examples of Absurdity No 2, work that mourns our loss of certainty and questions our place in the Universe. Another would be Ionesco’s The Chairs, which ends with a dumb orator, asked to “dazzle posterity with enlightenment”, mouthing noises at a room full of empty chairs.

Whether or not you agree with those Absurdists who think the Universe void, you must admire the humour with which they (Ionesco again) “exteriorise anxiety and project visible images of fear, regret, remorse, alienation”. You can quarrel with the content while relishing the form. Conventional plot, narrative logic and characterisation are mostly missing. Instead, you get dream, nightmare, hiccups from the subconscious, such as heads protruding from funeral urns (Beckett’s Play) or a giant corpse bursting into a living room (Ionesco’s Amedee).

Let Simpson have the last word. Always there are quirks, oddities, surprises in the “knockabout tragedies” that reflect his view that life is “excruciatingly funny”. But maybe he’ll take dark absurdity further at Hodge’s revival of his Tinkle. Or perhaps my notes are lying when they record the 88-year-old as saying: “It’s so unexpected. I’m just about to be lowered into my coffin when all this fuss turns up. It’s given me the idea of dropping dead at the first night. That would ensure maximum publicity.”

— Absurdia previews at the Donmar Warehouse, WC2 (0870 0606624) from Thursday and opens on July 31

Editor's choice

• U2 at Nou Camp Stadium, Barcelona
• The 50 Best Movie Villains
• The 15 golden rules of theatre etiquette