This weekend, "Logan" proved how much the game has changed for superhero movies.

A few years ago, no one would have made an R-rated "X-Men" movie, aged the characters well into their Social Security years, premiered it at the Berlin Film Festival, and released it in March -- under a title that does not have the words "X-Men" or "Wolverine" in it.

And yet, here we are, with "Logan" opening the first weekend of March with an estimated $85.3 million, boasting the best debut for a "Wolverine" film and the fifth-biggest debut ever for an R-rated film.

Here's how "Logan" defied the odds, the competition, and the old rules of superhero filmmaking.

1. Fans Love R-rated Comic Book Movies

Few superhero films go beyond the PG-13 rating, either because of their family-friendly comic-book origins, their fear of excluding potential young ticketbuyers, or their desire to protect a brand that depends heavily on merchandising to kids.

But Fox's "Deadpool" proved last winter that, not only is the R rating no impediment to box office success, it also satisfies the clamor of an adult fanbase, one that's big enough to replace all those under-17 kids. According to exit polling, some 83 percent of the audience was between 18 and 44, the demographic sweet spot that most movies would kill to hit. Granted, making an R-worthy movie isn't going to be the answer for every superhero (please, Warner Bros., no one wants to see an R-rated Superman), but at least some spandex-clad stars are ready to grow up.

2. Great Reviews

"Get Out" proved last week that, if a genre movie is good enough, cultivating critical raves (say, through festival screenings) is a smart tactic. That's what the "Logan" team did last month at the prestigious Berlin Film Festival. The result was a worldwide shower of positive buzz, leading to strong reviews -- 93 percent "Fresh" at Rotten Tomatoes. That helped attract the older audience necessary to make "Logan" a hit. Audiences agreed, giving "Logan" an A- CinemaScore, a grade that indicates very strong word-of-mouth.

3. You Can Open a Summer Movie in March

In the last few years, March has seen some of the biggest hits of a given year: 2010's "Alice in Wonderland," 2012's "The Hunger Games," and 2016's "Zootopia" and "Batman v Superman: Dawn of Justice."

This March, "Logan" is just the opening salvo in a month that will see "Beauty and the Beast," "Kong: Skull Island," "Power Rangers," "CHiPs," and "Ghost in the Shell." In earlier years, these would all have been summer releases, but now, they're the sort of movies that make March worth nearly 10 percent of a year's box office total.

4. #OneLastTime for Wolverine

No doubt many X-fans went to see "Logan" because it's been widely touted as the last film in which Hugh Jackman and Patrick Stewart will play Wolverine and Professor X. Of course, this is Hollywood, so never say never, but if the two stars really are hanging up their mutant superpowers after 17 years, it's no wonder viewers would want to take advantage of their last chance to see them ride off into the sunset.

Again, not every superhero movie is poised to take advantage of such an event, but franchise finales tend to draw fans out to theaters. You don't want to miss your last chance to see Wolverine slash his enemies -- or at least, your last chance until some new star takes up the adamantium claws.