The rise of MMA has created a sports audience literate in the consequences of combat, which has had considerable implications for movie-action design over the past couple of decades. Few understand this better than fourth-dan black-belt Kyokushin karate master, Expendables and Aquaman star Dolph Lundgren.

The Swedish action king has put his body on the line in a frankly impressive number of movies—mostly action, sometimes comedy—since his debut as Venz in the 1985 Bond film, directed himself in a small collection of them, too, and finds himself acutely invested in how the rise of Brazilian Jiu-Jitsu, Muay Thai, and other martial arts has changed the action-film scene.

“It's an interesting question, because you have two types of movies that deal with action,” Lundgren tells Letterboxd. “There’s superhero-franchise pictures, where the action is sort of fantastic and everybody’s kicking the guy through the wall, and the women are beating up nine guys at the same time. Then there’s the other side where people [who are] seeing MMA, they realize: how many punches can you take? How can you choke somebody out? How does the injury slow somebody down? I think there’s an authenticity in films that is slowly kind of getting closer and closer to the real fight—except maybe the superhero movies.”

Lundgren’s latest self-collaboration, Scott Adkins, who has fast become a martial-arts movie star in his own right, Lundgren’s age is on show as Shea, a prison guard of modest means whose daughter (played by his own offspring, Ida) needs expensive cancer treatment.

Adkins (Zero Dark Thirty, Doctor Strange) plays Mike, a washed-up English fighter with an old shoulder injury, who turns to construction temp work after having been submitted by a better competitor and thrown off his American MMA team. Mike’s latest job is to pull the last valuable scraps from an old hospital—the castle of the title—that’s set to be demolished in a matter of hours. Mike finds a big bag of cash, which Shea is hunting for following a tip-off, and a third, gun-toting bad guy, Deacon (played by stuntman supreme, Scott Hunter), is also after the loot.

The countdown-to-destruction narrative allows for plenty of exhaustive running up and down stairs, punching along hallways, and bona-fide bodily degradation. It’s this authenticity that Lundgren is most interested in these days. “You know, the old days, you’d have the bar fights with John Wayne, and people would crack each other across the jaw and come back up, or get shot and have a glass of whisky and everything’s fine, stick a rag in there.

“The rise of MMA and Jiu-Jitsu has changed the fight stuff. There is more groundwork. In this particular film I didn’t want anything crazy, or supernatural, or superheroic; [I wanted] stuff that could happen in a real fight.”

Action design is a complicated dance between the things that need to happen physically, and the things that matter to character. In Castle Falls, for example, Mike, having been submitted in the film’s opening fight, needs to learn how to win again, while Shea’s daughter’s life depends on his old knees carrying him up those relentless flights of steps. The film’s budget and Covid both placed limits on what was possible.

“I knew that with our limitations, I was gonna focus on fights, because I had Scott, who can fight,” says Lundgren. “I don’t need to double him, he can do his own fights and he had a great fight coordinator. It was very helpful to have Scott around because he is a perfectionist and I knew that if he is happy then I’m gonna be happy.”

Among the left hooks and uppercuts, Castle Falls features a fair whack of solid headbutts. Lundgren perks up when I ask him the secret to a good one. “Headbutts! Oh yeah. Headbutts. They’re underrated. I mean, that’s a close-quarter fight. If somebody gets close to you, what you wanna do is make sure you hit ’em with the hard part of your skull—if it’s a real headbutt. It’s kind of easy to sell on film. It’s kinda raw and kinda down-and-dirty fighting.”

The keys to stitching together convincing fight action, Lundgren knows, are many: meaningful character motivation, rising narrative stakes, great stunt personnel, multiple camera angles for the best edit options, and people behind those cameras who understand fight work. Adkins brought his friend Eric Linden to the party; the stuntman and stunt coordinator also operated the camera for this gig. “First of all he’s strong, and he can carry the camera for long takes. And then he can anticipate the moves as well. He knows there’s a left hook coming up so he can move out here to get it.”

Working alongside Linden was first-time feature cinematographer s Chen—a huge shoulder-tap from a star of Lundgren’s pedigree, which was intentional. “I was looking for somebody young and fresh and with another kind of vision. There’s something about the fact that she is a woman that I thought could be interesting. I was trying to get more emotions into the film and more human qualities in all the characters.”

The original He-Man and engineering graduate has lately been reckoning with the effects of an abusive childhood, with daily meditation a pivotal part of his personal renewal. Lundgren’s devotion to inner peace has made him more motivated to show other dimensions of men on screen. “It’s more becoming about the interior of the characters, you know? More about the humanity of the people. And if I’m directing, it’s important to me for the other actors to also feel excited about playing all the idiosyncrasies of a person.

“I’ve done all the action. I don’t get excited because I’m gonna do fights, or because I’m gonna fire a weapon or drive a car or something. It’s more about why, and trying to pull the audience in that way. That’s more exciting to me.”