“Kid, we’re gonna make you a star! But first, lose the halo.”

The trailer for Rules Don’t Apply, with its promise of one notorious playboy starring as another equally profligate real-life womanizer, set the bar high. You see, rules don’t apply to Warren Beatty. They never have. That’s part of the reason we love him.

This isn’t the first time the life of half-cracked adventurer Howard Hughes has been given the big-screen treatment. George Peppard played a variation on the eccentric billionaire in 1964’s epic guilty pleasure The Carpetbaggers. Jason Robards took home a best supporting actor prize for his work as the older Hughes in Jonathan Demme’s Melvin and Howard — for my money, the best American film of the 1980s. And Scorsese’s The Aviator did such a bang-up job of reproducing Hughes’s famed crash landing in a Beverly Hills neighborhood that Beatty wisely cut around it.

It’s been more than a decade since the actor-producer-writer-director stood before a camera (Town & Country) and almost double that since last he looked through a viewfinder (Bulworth). The appeal of playing Hughes is understandable, and Beatty’s brilliant turn as a befuddled madcap is as close as he will ever get to channeling the power of Marion Lorne, Aunt Clara on TV’s Bewitched.

But it’s only when attention strays to a subplot involving juvenile leads Lily Collins and Alden Ehrenreich that the rules really fly out the window. Ehrenreich stars as one of Hughes’s drivers assigned the task of chauffeuring contract player Collins, the catch being that their boss forbids his employees to date.

Cary Grant walked away from acting after the screen’s most romantic leading man found himself playing matchmaker to Samantha Eggar and Jim Hutton in Walk, Don’t Run. Beatty may regret not following Grant’s lead.

Ehrenreich first came to our attention in the franchise that never was, Beautiful Creatures. After playing Snow White in Mirror, Mirror, Collins hitched her star to The Mortal Instruments, another lurking series that failed to spark a sequel. Ehrenreich at least captures the look and feel of the ambitious coachman — part DiCaprio, part Andy Griffith in his “Lonesome” Rhodes period. All Collins has to show for herself is a pretty face equipped with a pair of strikingly non-emotive eyebrows.

Beatty’s vanity doesn’t permit him to leave the house without a lighting cameraman in tow. For the first third of the picture, the actor works in shadow, as though high key lighting would have the same effect on his kisser as did a bucket of water on the Wicked Witch of the West.

Beatty’s vanity also ensured a sex scene between Hughes and the young ingenue be written into the script. Graciously agreeing to indulge an old man’s fantasy both on and off screen, Collins’s tea-totaling virgin inexplicably gulps down a bottle of champagne before hitting the sheets with Howard. Without some acting lessons, Collins’s legacy could be that of the last woman to bed Beatty on screen.

That’s not to say the film is totally void of charm. There’s Annette Bening and a very amusing Matthew Broderick as Collins’s concerned stage mother and Howard’s man Friday, respectively. Caleb Deschanel’s lush, evocative reflections on ’60s Technicolor, coupled with visual effects supervisor John Scheele’s stunning CGI revival of the illusory art of process photographer extraordinaire Farciot Edouart do much to mobilize Beatty’s vision. But with all of the stories written about Hughes, was there really a need to rely upon fictional characters to advance the plot? Better a goosed Hughes than an unspruced flirtation between bumpkins.