Considered to be a wild, bizarre and comic play, significant for the way it overturns cultural rules, norms and conventions, it is seen by 20th- and 21st-century scholars to have opened the door for what became known as modernism in the 20th century, and as a precursor to Dadaism, Surrealism and the Theatre of the Absurd.

The play – scheduled for an invited "industry" run-through followed by a single public performance the next night – caused a riotous response in the audience and denunciatory reviews in the days after.

To some of those who were in the audience on opening night, including W. B. Yeats and the poet and essayist Catulle Mendès, it seemed an event of revolutionary importance, but many were mystified and outraged by the work's seeming childishness, obscenity, and disrespect.

It is the first of three stylised burlesques in which Jarry satirises power, greed, and their evil practice – in particular the propensity of the complacent bourgeoisie to abuse the authority engendered by success.

He wanted King Ubu to wear a cardboard horse's head in certain scenes, "as in the old English theatre", for he intended to "write a guignol".

He thought a "suitably costumed person would enter, as in puppet shows, to put up signs indicating the locations of the various scenes".

As the play begins, Ubu's wife convinces him to lead a revolution, and kills the King of Poland and most of the royal family.

Back at the palace, Ubu, now King, begins heavily taxing the people and killing the nobles for their wealth.

Ubu knocks down the attackers with the body of the dead bear, after which he and his wife flee to France, which ends the play.

Ubu Roi is considered a descendant of the comic grotesque French Renaissance author François Rabelais and his Gargantua and Pantagruel novels.

[9][10] The language of the play is a unique mix of slang code-words, puns and near-gutter vocabulary, set to strange speech patterns.

[11] "The beginnings of the original Ubu", writes Jane Taylor, "have attained the status of legend within French theatre culture".

While his schoolmates lost interest in the Ubu legends when they left school, Jarry continued adding to and reworking the material for the rest of his short life.

His plays are controversial for their scant respect to royalty, religion and society, their vulgarity and scatology,[13][14] their brutality and low comedy, and their perceived utter lack of literary finish.

[7] Jarry's metaphor for the modern man, he is an antihero – fat, ugly, vulgar, gluttonous, grandiose, dishonest, stupid, jejune, voracious, greedy, cruel, cowardly and evil – who grew out of schoolboy legends about the imaginary life of a hated teacher who had been at one point a slave on a Turkish galley, at another frozen in ice in Norway and at one more the King of Poland.

While Ubu may be relentless in his political aspirations, and brutal in his personal relations, he apparently has no measurable effect upon those who inhabit the farcical world which he creates around himself.

Jarry said to the audience in a curtain speech just before that first performance in Paris: "You are free to see in M. Ubu however many allusions you care to, or else a simple puppet—a school boy's caricature of one of his teachers who personified for him all the ugliness in the world".

I say, 'After Stéphane Mallarmé, after Paul Verlaine, after Gustave Moreau, after Puvis de Chavannes, after our own verse, after all our subtle colour and nervous rhythm, after the faint mixed tints of Conder, what more is possible?

[20] In 1964 the Stockholm Puppet theatre produced a highly popular version of Ubu Roi directed by Michael Meschke, with scenery by Franciszka Themerson.

Performed in Brisbane, Australia, the adaptation made cultural political references to Queensland's Premier Campbell Newman, even including him in the show's promotional poster.

[27] In 2013, the international theatre company Cheek by Jowl created a French-language production of Ubu Roi, directed by Declan Donnellan and designed by Nick Ormerod.

[29] According to The New York Times "the Cheek by Jowl production asks us to see Jarry’s play through the eyes of a sulky, moody, sexually tormented adolescent, who is pitilessly judgmental of his elders.

In February 2020, the Vernal & Sere Theatre staged a world-premiere adaptation in Atlanta, Georgia called UBU, which imagined the titular character of King Ubu as a principal walking the halls of a quintessential American school and called into question the fundamental system by which the United States governs and instructs its citizenry.

Alfred Jarry is one of the few real figures to appear among the many literary characters in Les Faux-Monnayeurs (The Counterfeiters, 1925), by André Gide.

The figure of Ubu Roi, particularly as depicted by Jarry in his woodcut, appears to have inspired the character Oogie Boogie in Tim Burton's animated film The Nightmare Before Christmas.