Winners and losers, orgies of gratitude, generous lashings of false humility — these are the things we expect from the Oscars. Beyond that, there are truly no certainties but one. There will be tuxedos.

Durable, serviceable, flexible, the tuxedo is a time-tested form of combat gear for night owls, the epitome of uniform dressing and yet, for some reason, a form of suit that gives people the willies. It’s prom drag, they think. Or that ill-fitting rental sack with a stale Mentos in the pocket. Lately, though, the perception of how to wear evening clothes is changing, never more obviously so than on the red carpet, where in a cavalcade of penguin suits, both traditional and innovative, celebrities and their stylists have been giving us a master class in dressing up.

At the recent Screen Actors Guild Awards, Bradley Cooper, Steven Yeun and Matt Bomer were close to impeccable wearing more or less regulation black tie, while others in the celebrity cohort made a point of showing how truly flexible this sartorial warhorse can be. The tuxedo was tweaked almost to the point of redefinition, with versions of it rendered single- or double-breasted, adorned with crisscross lapels and cropped like a bellhop’s bolero. There were tuxedos that night in bronze, brown, midnight blue, lipstick red, blush pink and, most memorably, ivory, as Jeremy Allen White bid to switch up his thirst-trap underwear-model image for something more suggestive of a leading man.

Dressed in a Saint Laurent tuxedo over an open shirt and with a diamond Schlumberger Bird on a Rock brooch pinned to his lapel, Mr. White evoked adjectives not often associated with millennial bros. Like a short-king avatar of Cary Grant, he was sophisticated, suave and — let’s just say it — debonair.

In the realm of replicating old time Hollywood glamour, Mr. White had plenty of competition that evening. And in light of the parade of elegantly tuxedo-clad celebrities like Tyler James Williams (baby blue double-breasted Amiri), Glen Powell (shawl-collar bronze Brioni), Ryan Gosling (dove gray Gucci) and Cillian Murphy (pinstriped Saint Laurent), it seemed clear what to expect on the Oscars red carpet.

That is, no wardrobe stunts. Those are better left to the glorified costume party that is the Met gala. The Oscars, after all, is Hollywood’s big date night, in that it has a certain instructive quality of use to any civilian preparing for a red-letter day.

“I always think the point of dressing for these occasions is what do you want your mom and dad to remember the occasion by?” the designer Todd Snyder said. Will it be that suit of armor or a chain-mail singlet you decided to wear to the Hollywood prom?

“What guys like Timothée Chalamet were doing on the red carpet was interesting until it went cockadoodle,” he said. “There is good reason the classics endure.”

Foremost is that, like suits themselves, the tuxedo solves a problem. Crisp and sober and dignified, it streamlines a man’s silhouette and is intrinsically elegant. “The simple way to dress is always the more elegant, and the tuxedo is untouchable as an emblem,” said Gianluca Isaia, the chief executive of Isaia, a Neapolitan luxury men’s wear label founded by his grandfather in 1920.

In short, it is a uniform, one clearly denoting leisure and a sense of occasion. And daunting as the tuxedo can seem, it is in reality one of the more bombproof men’s wear formulas.

“It’s actually the coolest look and so simple,” Mr. Snyder said. It certainly seems so when worn by Jon Hamm or George Clooney, actors whose styles hark back to Tinseltown’s studio heyday and dapper stars like Fred Astaire.

In his dress, as in other ways, Grant was a total self-creation, and anyone looking for a black-tie primer could do worse than stream his 1962 film “That Touch of Mink.” In that otherwise forgettable Doris Day rom-com, Grant was the acme of chic, clad in a single-breasted midnight blue wool dinner suit with — here things get geeky — satin-faced peak lapels, forward pleated trousers with silk seam piping, a white pleat-front formal shirt with single-button gauntlet cuffs, a midnight blue butterfly bow tie and black patent leather opera pumps.

If this all sounds hopelessly complex, particularly for those who don’t wear a suit or shoes that lace, it need not be, said John Tighe, the president of Tailored Brands, which owns the mass-market Men’s Wearhouse chain. “The minute you step into a store, we have someone waiting to walk you through the process,” Mr. Tighe said.

With or without guidance, it is worth the effort to make friends with a tuxedo. “It’s a chance for people to be a best version of themselves,” said the photographer Mark Seliger, whose latest book, “Vanity Fair: Oscar Night Sessions,” is chockablock with the handsome studio portraits he shot across the decades since be began photographing stars arriving for Hollywood’s most vaunted wingding.

What is it about a tuxedo that automatically elevates its wearer? “That’s easy,” Mr. Seliger said. “It’s the classic, beautiful simplicity.”

Photo credits Jutharat Pinyodoonyachet for The New York Times (Andrew Garfield, Austin Butler, Bill Nighy, Brendan Fraser, Charles Parnell, Jay Ellis, Ke Huy Quan, Michael B. Jordan, Ryan Seacrest, Sarah Polley); Eric Gaillard/Reuters (Elliot Page, Jacob Elordi, Rami Malek); Jordan Strauss/Invision, via Associated Press (Simu Liu); Frazer Harrison/Getty Images (Jon Hamm)

Produced by Tanner Curtis, Gabriel Gianordoli and Shannon Lin.