Hugh Hefner, the pipe-smoking, Pepsi-quaffing founder of Playboy magazine, whose cheerfully prurient vision of the good life made him a founding father of the sexual revolution, died Wednesday. He was 91.

His death was announced by his company, Playboy Enterprises Inc.

The only people ever to call Mr. Hefner “Hugh’’ were his parents: From boyhood on, to friend and stranger alike, he was simply “Hef,’’ a name that seemed as much honorific as diminutive. His nickname underscored the somewhat unreal quality Mr. Hefner projected. At once exalted and banal, he cut a curious figure that owed as much to the eccentricity of a Howard Hughes as it did to the libertinism of a Casanova.

Mr. Hefner might go months at a time without leaving the Playboy Mansion, his 48-room residence in Chicago, or the Playboy Mansion West, the Los Angeles estate he moved to in the 1970s. His preferred mode of dress was pajamas, and his plebeian palate was legend. He drank up to 25 bottles of Pepsi a day (after suffering a stroke, in 1985, he reduced his intake and switched to decaffeinated Diet Pepsi). He was also known to lament, “I have a 24-hour kitchen, why can’t I have chicken like they make at Kentucky Fried Chicken?’’

Mr. Hefner often remarked that his mother, a devout Methodist, had wanted him to become a missionary. Mrs. Hefner got her wish, even if the faith for which her son proselytized in no way resembled any she herself might have professed. Asked once what his proudest accomplishment was, Mr. Hefner replied: “That I changed attitudes toward sex. That nice people can live together now. That I decontaminated the notion of premarital sex. That gives me great satisfaction.’’

He was American Puritanism’s revenge on itself — quite literally, being a direct descendant of William Bradford, the second governor of Plymouth Colony — and Mr. Hefner took his role as America’s high priest of hedonism with the utmost seriousness.

This was clear as early as his undergraduate days. In a school magazine, the young psychology major hailed Alfred Kinsey’s study “Sexual Behavior in the Human Male’’ for making “obvious the lack of understanding and realistic thinking that have gone into the formation of our sex standards and laws. Our moral pretenses, our hypocrisy on matters of sex have led to incalculable frustration, delinquency, and unhappiness.’’

The answer to America’s plight? Playboy Enterprises Inc., a leisure-time empire that made Mr. Hefner a millionaire many times over. Its holdings variously included magazines, nightclubs, gambling casinos, book publishing, hotels, music, movies, videos, and cable television.

The company’s centerpiece — and for many years its cash cow — was Playboy magazine. Long after surrendering the title of chairman to his daughter, Christie, in 1988, Mr. Hefner remained the magazine’s editor in chief. He continued to personally approve each month’s “playmate’’ (as the nude women who appeared in the magazine’s centerfold are called) and paid editorial attention in such exquisite detail that bemused staffers dubbed him, only in part facetiously, “World’s Wealthiest Copy Editor.’’

In 2016, the magazine announced that it would stop running nude photographs of women.

The magazine’s logo, the silhouette of a tuxedoed rabbit, became one of publishing’s most recognized images, and at the height of its popularity, in 1972, Playboy boasted a circulation of 7,012,000.

Mr. Hefner’s genius was to see as early as 1953, when Playboy debuted, that sex need no longer be marketed furtively. His magazine was a world removed from publications with names like Wink, Cutie, and Eyefull, the ones he read — or, rather gazed upon — as a young man. Central to Playboy’s appeal was its portraying sex as not just fun but glowingly licit. After initially using models and burlesque performers as playmates, Mr. Hefner realized that his readers would find the unclothed wholesomeness of the girl next door more attractive — and more arousing — than the knowing looks of women who disrobed professionally.

“We suppose it’s natural to think of the pulchritudinous Playmates as existing in a world apart,’’ an early issue declared. “Actually, potential Playmates are all around you: the new secretary at your office, the doe-eyed beauty who sat opposite you at lunch yesterday, the girl who sells you shirts and ties at your favorite store.’’

Comely saleswomen were not the sole reason Playboy readers had favorite stores. Almost as important as Mr. Hefner’s realization that sex was moving into the mainstream of American culture was the related insight that it was attaining the status of a lifestyle. Playboy would be “a pleasure-primer styled to the masculine taste,’’ Mr. Hefner announced in the inaugural issue. “We enjoy mixing up cocktails and an hors d’oeuvres or two, putting a little mood music on the phonograph and inviting in a female for a quiet discussion on Picasso, Nietzsche, jazz, sex.’’

Those words read like parody today, but in 1953 they held the force of revelation for millions of upwardly mobile American males. Sex, Mr. Hefner had intuited, was beginning to be perceived as an emblem of success, and advertisers embraced the magazine’s vision of concupiscent consumption, one in which stereo equipment, sports cars, and expensive clothes were no less desirable — and considerably more attainable — than the beautiful women in various stages of undress populating its pages. Even as Playboy anticipated the sexual liberation of the 1960s, it embraced the great economic boom of the ’50s.

The magazine attended to more than just readers’ libidos and wallets. A sheepish refrain, “Actually, I read it for the articles,’’ provided a punch line for any number of jokes about Mr. Hefner’s handiwork. Yet Playboy’s contents could justify those words. For alongside such mainstays as Playboy’s Party Jokes and the Playboy Advisor, the magazine published fiction by the likes of Vladimir Nabokov, James Baldwin, and Isaac Bashevis Singer. And for all that it added to the vocabulary of masculine adolescence such coinages as “au naturel’’ and “pictorial,’’ the magazine also provided a forum for such figures as Malcolm X and the philosopher Jean-Paul Sartre in its monthly Playboy Interview, whose extended question-and-answer format marked a real innovation in American journalism.

Mr. Hefner’s idea of what constituted “Entertainment for Men,’’ as Playboy bills itself, proved as controversial as it did lucrative. Yet the most damaging assaults came not from moralists — soon enough, Playboy would seem relatively tame compared to the many imitators it inspired — but from the women’s movement. Mr. Hefner had always striven to defuse attacks from organized religion. (One well-publicized ploy was to offer clergymen a discount on subscriptions.) He was at a loss to refute feminists who charged that Playboy patronized and objectified women.

Mr. Hefner stoutly rejected such accusations. A champion of progressive causes, he was a generous supporter of the American Civil Liberties Union, the Urban League, and the National Organization for the Reform of Marijuana Laws, among other groups. Sexual liberation was a matter of principle to him as well as profit. He put his money where his mouth (and much else besides) might be, devoting 25 issues during the early ’60s to his “Playboy Philosophy,’’ an exceedingly earnest if also generally incomprehensible 250,000-word treatise on sex and society.

He often sought to defend Playboy against critics. Yet, at times he proved his antagonists’ point. “The feminists who criticize us,’’ Mr. Hefner said, “don’t realize how Playboy, far more than the women’s magazines, is responsible for the nongirdle look, the bikini, the mini-skirt, the openness to nudity.’’ This was, to say the least, a somewhat idiosyncratic interpretation of what constituted women’s liberation. As the writer Susan Brownmiller said to him during a debate, “When Hugh Hefner comes out here with a cotton tail attached to his rear end, then we’ll have equality.’’

Brownmiller was referring to part of the costume of the waitresses, or “bunnies,’’ who worked at the supper clubs the company opened during the 1960s. “Always remember,’’ the 44-page Bunny Manual proclaimed, “your proudest possession is your Bunny Tail. You must make sure it is white and floppy.’’ The first Playboy Club opened in Chicago in 1960 and within a year had more than 100,000 “keyholders,’’ the name for patrons who paid an annual fee for the privilege of visiting the clubs. Eventually, there were 22 clubs, on three continents, and they became second only to the magazine in extending the company’s frisky cachet. Boston had one, on Park Square, from 1966 to 1977.

The writer Gloria Steinem, who briefly worked as a bunny, famously punctured the chain’s sophisticated image, revealing how its waitresses were underpaid, overworked, and generally exploited. More damaging to the chain’s reputation was the sexual openness of the 1960s, which made the clubs seem passe — if not outright ludicrous. The last one closed in 1988. Even the magazine felt the effects of the ’60s, and with the rise to prominence of the rival monthly Penthouse in the 1970s, Playboy ceased to dominate its market. While the magazine remained popular, gone was its unique hold on the imagination of the American male. Playboy’s decline didn’t affect Mr. Hefner’s lifestyle, which remained happily hedonistic. “I don’t take a lot, but I take it when it’s called for,’’ he said to The New York Times in 2011 about his Viagra use. “It’s God’s little helper.’’

Hugh Marston Hefner was born in Chicago, the son of an accountant and a housewife, Glenn L. and Grace. Both he and his brother, Keith, chafed at their restrictive upbringing.

A shy adolescent, Mr. Hefner demonstrated more interest in cartooning than in dating. After two years of Army service, he went to the University of Illinois — largely because his high school girlfriend, Mildred Williams, was there.

Mr. Hefner failed at selling a comic strip, “Fred Frat,’’ and held a succession of unrewarding office jobs: personnel director for a small carton manufacturer, and promotional writer for Esquire magazine.

At the time, Esquire, with its “Vargas Girl’’ pin-ups, was considered the height of mass-market raciness. Mr. Hefner began to entertain notions of his own men’s magazine. He envisioned “an entertainment magazine for the city-bred guy — breezy, sophisticated.

He invested his entire savings in the project, $600, and raised another $10,000 from the sale of stock to family and friends. The magazine was to be called Stag Party — until an outdoors publication named Stag objected. Gent, Gentry, Gentleman, Pan, and Satyr were among alternatives weighed.

They settled on Playboy.

Mark Feeney can be reached at mfeeney@globe.com.