Robert Downey Jr. may now want to start practicing his Oscar speech.

The “Iron Man” star, whose life and career has already been the stuff of legends, is often mentioned as the man to play media and pop culture icon Hugh Hefner in any Hollywood biopic.

And that particular juggernaut gets a significant boost with the recent release of an illuminating documentary, “Hugh Hefner: Playboy, Activist and Rebel,” written, produced and directed by Canadian filmmaker Brigitte Berman.

Having sent jazz aficionado Hefner a copy of her award-winning feature documentary “Bix: ‘Ain't None of Them Play Like Him Yet’” about one of his favorite musicians, jazz cornetist Bix Beiderbecke, Berman developed a friendship with the publishing mogul and was invited to his momentous 80th birthday party at the Playboy Mansion in 2006.

In a masterful and engrossing 124 minutes, Berman, who was given unprecedented access to the man known simply as “Hef,” unravels a story few people knew and will leave a legacy that sharply divides his fans and foes.

To his critics, Hefner is a monster who began the moral turpitude of America by
peddling smut that objectified and degraded women, while contributing to the liberal hedonism that foreshadowed the 60s revolution of sex, drugs and rock and roll.

Meanwhile, others see him as an American hero, a free-thinking renegade who liberated society from the dark forces of Puritanism and was influential in preserving First Amendment rights and championing racial and social justice.

For instance, in the late 1950s, Hefner debuted his Playboy Penthouse television series, a precursor to the late night chat shows that featured Black entertainers who were banned elsewhere.

And in the early 1960s, when Playboy clubs in Miami and New Orleans would not allow Black patrons into the establishments, Hef used his own money to buy back the franchises taking a financial hit.

Within the next two decades, he also defied the McCarthyite blacklist by employing great writers like Dalton Trumbo, vehemently opposed the Vietnam War, provided legal teams to fight anti-abortion laws that eventually led to Roe v. Wade and campaigned against censorship and for the individual’s right to freedom of expression on all fronts.

Meanwhile, in the 1980s he had to fight his own battles against the Reaganite religious right, when a government commission dubbed his magazine
pornography and took steps toward to ban it. He also dealt with personal anguish following the brutal killing of Playmate Dorothy Stratten, which led to a debilitating stroke.

In expertly edited interviews that weave a tight narrative through Hefner’s life, a veritable “Who’s Who” of famous names, including Tony Bennett, Dick Gregory, Pat Boone, Joan Baez, Jim Brown, James Caan, Reverend Jesse Jackson, George Lucas, Gene Simmons and Bill Maher, expound on his cultural relevance.

Hefner’s story was that of many American youth of his generation. Born and raised in Chicago to conservative parents, he found early escapist fantasy in jazz music and cartoons in high school, and, his curiosity piqued in areas of the human psyche, studied philosophy at the University of Illinois at Urbana-Champaign.

A few years out, he was a copywriter for Esquire magazine, and by this time, married with a young child had seeming acquired the American dream: stability and abject boredom.

“I recalled standing on the Mackinac (pronounced Mack-in-naw) Bridge and looking out over Lake Michigan thinking is this all there is,” Hef revealed.

Well cometh the hour, cometh the man and shortly afterwards Hefner came up with the idea of publishing his own very different men’s magazine.

He originally wanted to call it “The Stag Party,” after a popular local club, but a legal “cease and desist” letter put an end to that, and the Playboy empire was born.

Now in most success stories, luck and timing can play a key role and Hef’s double dose came when he persuaded a Chicago photographer who owned the copyright to a nude photo of a model named Marilyn Monroe to let him use it for his first centerfold.

Thus, Playboy’s launch in December 1953 featured the alluring charms of what would become Hollywood’s most enduring sex symbol and the magazine achieved instant notoriety and success. Its initial 2,000 copy print run ended up selling 7,000 issues.

In one of the best lines in the film, when thinking of Hef today with his trademark silk robe and matching blonde girlfriends, Dick Cavett opines: “He gives wonderful hope to men over 100.”