IT’S A TWIST of nomenclature worthy of a comic book. If you were going to cast a costumed man to help redefine what an “R” can pull off in Hollywood, it might seem too far-fetched — too perfectly neat or on the nose — that his own initials be a triple-R.

In this case, though, truth is stranger than alliteration, because Ryan Rodney Reynolds has just proved to be a game-changer for “R”-rated superhero movies at the box office.

This holiday weekend, Reynolds’s new comeback film — a little something called “Deadpool” — has not only recouped its modest $58-million production budget by its domestic debut alone. The 20th Century Fox flick has also blown well past all studio hopes and projections for the Presidents’ Day frame — $135-million for three days, and $150-million over the holiday weekend — and in doing so, has redrawn much of the industry picture for the 21st-century adult comic-book film.

It’s not that R-rated superhero-world films haven’t before found success at the box office, of course. Starting in 1998, for example, the “Blade” action-horror franchise — fittingly co-produced by longtime Marvel mastermind Stan Lee — eventually soared into the $400-million neighborhood. And more broadly, such grim-and-gritty comic-book adaptations as 2002’s “Road to Perdition” ($181-million worldwide) and 2005’s “Sin City” ($159-million) have scored big with grownup audiences (faring better than such attempts as “Watchmen”).

Yet what has just happened this weekend is different, because “Deadpool” — given the antihero character’s cinematic universe and the film’s market influence — will birth a world of change, effectively becoming the “Iron Man” of the R-rated superhero film.

This certain industry awakening, of course, will be first sparked by the sheer surprise of this weekend’s projected numbers. Heading into the domestic debut, Fox was guardedly hoping for a $60-million holiday take. Then the film kept tracking upward, until by Saturday, the Hollywood trades were predicting a massive $130-million opening — the kind of number that especially makes every studio that holds a comic-book property sit up and take notice.

Update: By Sunday, according to box-office estimates, “Deadpool” was breaking such domestic records as the biggest February opening and biggest Presidents’ Day weekend debut ever (both previously held by “Fifty Shades of Grey”); biggest opening ever for an R-rated film (previously “The Matrix Reloaded”); biggest debut ever for an R-rated comics adaptation (until now, “300”); and even the biggest opening ever for Fox (topping 2005’s “Star Wars: Revenge of the Sith,” which opened to $108-million). Final numbers are due Monday.

The film also has already passed the quarter-billion-dollar mark worldwide.

Given such a head-turning coming-out for “Deadpool,” which was savvily slotted into a slow month, the first wave in the ripple effect will surely be swift.

What is unfolding, in fact, can be unpacked on several telling levels:

1. The R-rating, as audience magnet, can attract as well as repel.

Hollywood’s conventional wisdom has been that if you make a comic-book adaptation, you generally can’t risk excluding its younger fans. It’s better to stay just within the bounds of that PG-13 rating, as Christopher Nolan’s “Dark Knight” franchise did.

This weekend, though, brings a fresh takeaway: Peruse Tumblr for even a few minutes and you realize that the “R” rating actually serves as enticement to many teen geeks, partly because it rings as respectfully authentic to the mature comic-book content. When a nerd-world property stokes such passion, the “R” rating isn’t such a high barrier to “persuade a parent” access. Especially when…

2. The superhero film wears the clothes of a comedy.

If Hollywood views the success of “Deadpool” only through the prism of R-rated superhero movies, it will have missed much of the point. A vital part of the massive appeal is that the quick-lipped Deadpool — true to the meta-humor of the 1991-spring Marvel comic — may don the bloodstained suit of an antihero, but he also is wearing the clothes of a clown. (Put another way: By breaking the fourth wall, John Hughes-style, the humor interestingly has the twin effect of helping to knock down the restricted multiplex door.)

Throw in enough sarcastic asides, after all, and you aren’t just taking the adolescent kids to see an R-rated Spandexed character; everything is now packaged within the parentheses of a raunchy comedy. “Deadpool” suddenly draws audience comparatives to such R-rated comedies as “Ted,” “The Hangover” franchise, much of Judd Apatow’s IMDB resume and even, fittingly, Ryan Reynolds’s “National Lampoon’s Van Wilder.” Or put more simply: Iron Man becomes Irony Man.

Which is particularly intriguing because…

3. “Deadpool” is the new “Iron Man.”

Way back in 2008 — an eternity ago in superhero-franchise years — a newly middle-aged actor with the gifts of charisma and comic fast-patter donned a super-suit, and everything changed.

That actor, of course, was Robert Downey Jr., as directed by Jon Favreau in Paramount’s lightning-in-a-(liquor)-bottle “Iron Man.” That massive success , as we know, became the true kickstarter for the modern Marvel Cinematic Universe, especially once Disney soon swooped in for a $4-billion buy of Marvel characters — and Marvel Studios never looked back as Tony Stark helped build a sure and methodical path toward “The Avengers.”

Now, nearly a decade later, Reynolds might swiftly become the RDJ of the R-rated arc.

It’s not just that Reynolds, at 39, now similarly stands poised to ride his once-second-tier Marvel character through multiple blockbusters (the sequel deal is reportedly already inked) en route to a billion-dollar franchise. Or that Reynolds — as with Downey in 2008 — is said to be “perfect” for his super-role, as if a custom fit.

No, it’s also that Deadpool — as Iron Man once did — can now become the springboard figure for launching an entire new assemblage of characters. The Pandora’s box of R-rated comic-book adaptations within an interconnected universe is now unleashed. Deadpool is not only tethered to the X-Men universe, but also comics characters like the mutants Colossus and Negasonic Teenage Warhead.

“If we’re doing a bunch more Deadpool movies,” Reynolds told FILMSTARTS, “we’re really going to explore the X-Men a lot. We’ll see, and maybe X-Force — X-Force is my priority,” referring to the X-Men offshoot.

Could Deadpool and Olivia Munn’s Psylocke (from the upcoming “X-Men: Apocalypse”) soon be fighting alongside Archangel and Sunspot? The opportunities suddenly appear wide open.

That all looms as especially interesting because…

4. R-rated crimefighters (still) have broad adult appeal.

If “Deadpool” ends up having an influence well beyond superhero films, it will partly be because it serves as a loud reminder: Whether it’s a space western or a sci-fi detective story, the R-rated action-adventure film can be a monster hit if the right charismatic actor is in the lead. And in turn, the crossover appeal beyond the fanboy throngs can be massive. That “R” rating can function like a dog-whistle to adults who might shy away from pure rock-’em, sock-’em super-fights by men in brightly colored codpieces. Give them a dark and edgy comics-adapted detective story instead — like, say, “Kingsman: Secret Service” or Netflix’s “Jessica Jones” — and it’s like catnip to those grownups who might eschew traditional capes and cowls, but who still love a great feral clawfight between mighty combatants.

And thanks to “Deadpool,” bandwagon-happy Hollywood suits should hear the message anew: If you build funny and darkly textured R-rated films, we will come. In droves. 

This post has been updated.