It's been 20 years since The Matrix first stunned the world with its game-changing action style, a brilliant blend of balletic martial arts moves and groundbreaking visual effects. The fight scenes were like nothing most audiences had ever seen before, but making all that action happen wasn't as simple as just hitting a button and downloading all those slick kung fu skills.

Being major fans of Hong Kong martial-arts cinema, the Wachowskis went straight to the source and hired the legendary action choreographer Yuen Woo-ping to help them shape the fight scenes and turn the actors into actual fighters who could be seen to be doing their own stunt work. (Whenever possible, that is. Keanu Reeves had some physical limitations after having neck surgery to separate two fused vertebrae; fortunately, he had an excellent stunt double: Chad Stahelski, who went on to direct the very Matrix-like John Wick movies.)

SYFY WIRE talked to Yuen, Stahelski, and the movie's Australian stunt coordinator, Glenn Boswell, about how this action classic came together.

Credit: Warner Bros.

Yuen Woo-ping: The Wachowskis had been trying to get in touch with me for a while. Eventually, they were able to find a Hong Kong producer who found me and told me about the project. I flew to America to meet them. I had so many questions, because at that time no one had seen a film like The Matrix. Nothing like it had been made in Hong Kong or America.

Chad Stahelski: We knew when we were making it that it was something special. That we were being taken in a different direction from what had ever been done, and that the final product was going to be something to the left or right of what everyone else was doing.

Yuen: The Wachowskis wanted fighting that was very stylized. We did storyboards. We did stunt viz, homemade videos shot in the dojo. It was a process of constant brainstorming and refinement.

Glenn Boswell: I came to America and met with the Wachowskis, Yuen Woo-ping, and the actors. They had already been training for some months in martial arts, and were becoming martial artists in their own right, so that we could get away with a lot of close-ups.

Stahelski: It was creating heroes — how do you do that? The Wachowskis took a page out of the Hong Kong book and decided let's get the cast members and train the s**t out of them in martial arts choreography. That takes an enormous amount of time. And wire work may look fun, but it's painful. You're in a tiny little harness, and it's wrecking your hips and squeezing your other parts, so the level of endurance you have to go through every day, for months? It's phenomenal. Very few people do what the Wachowskis were demanding of their cast. And the evidence of that? Have you seen anything that's close to The Matrix since?

Yuen: We had four months to train and prep, which is a lot of time by filmmaking standards. But Chinese martial arts really take a lifetime to master, so in those terms, we were in quite a hurry. The first time I assessed the actors' physical abilities, I thought for sure we'd never get them in fighting condition in time. I assigned each main actor a stuntman from my team as a conditioning coach, to make sure the actors did their stretching, choreography, and conditioning.

Stahelski: There was a casting-call audition for a martial arts stuntman to double Keanu Reeves, who was already an action star by then. And remember, at this time, martial arts and Hong Kong cinema hadn't punched a hole in the industry over here. It was very low budget at the time. Most of the stunt fights happening in big-budget films were punch-em-ups — there was no kicking, no flipping, no wire work. Before the audition, I was working on a stunt where I was doing a foot chase and I get hit by a car, and I didn't realize there was a cut on my head that was still bleeding. So I showed up for the audition, and I'm in a bloody T-shirt and jeans, and they looked at me like, "You okay?"

"Yeah, I'm okay. It's just a little blood." I instantly recognized Yuen Woo-ping. He had like eight of his guys with him; a few of them I recognized from Jet Li and Jackie Chan movies. And I was like, "Oh, wow. This is the real deal."

Boswell: The Chinese team didn't all speak English. That was a bit of an issue. There were certain things they wanted to do that we couldn't do, based on government guidelines, and we had to try to explain that to them. Some of it was simple things, like when they used a wire, and they tied a knot in the wire to connect it to the actor, and that's illegal. Certain wires cannot sustain a person, or there are certain ways you have to use a pulley. The stunt department ended up rigging most of the wire work. The wire work that the Chinese would do was more about suspending actors during a fight, and the wire work that the stunt department would do was anything that involved flying, leaping, or having heavy impacts.

Stahelski: Through an interpreter, Yuen Woo-ping says, "Look at this guy" – it was their youngest guy, this 22-year-old fireball named Chen. "Do whatever he does." And without any warm-up or anything, I followed this amazing, acrobatic martial arts guy and did every trick, tumble, kick, everything you can imagine, that he did. The average audition is three to five minutes; this was 90. So I'm dripping in sweat, blood, and tears to impress these guys. We shake hands, and I leave. I don't hear anything for a month.

And then I get a call, "Hey, would you mind coming back?" So I went back and did the exact same audition again. It was the same experience of 90 minutes of doing everything I knew how to do, and failing miserably at all the things I didn't know how to do. A couple of weeks later, they called and offered me the job.

Yuen: Chad doubled Keanu, so it was important that both he and Keanu could pick up the martial arts before filming began.

Credit: Warner Bros.

Stahelski: Keanu Reeves surprised me. He was wearing a neck brace, because he'd recently had neck surgery, and he still did at least 95 percent of the martial arts choreography. He actually performed way past the majority of the martial arts sequences and the wire work.

If there was a lot of impact — people getting smashed or thrown — or a really twisty flip, then it's probably a double. Otherwise, it's Keanu. And they worked the choreography and what he would do based on what his neck was capable of. That's one of the things the Wachowskis were great at. They want you to believe in the character. They don't want you to believe it's Chad, or it's Keanu Reeves, they want you to believe that it's Neo. As long as we don't let that illusion slip, we're good.

Yuen: I had lunch with Hugo Weaving recently, and he reminded me of the toll the training took on the actors. Everyone had injuries from the intensive process. It was all created with blood, sweat, and tears.

Boswell: Trinity running across the rooftops and jumping across — Carrie-Anne Moss did that herself. She was great. That was bloody difficult to do. We spent a couple weeks rehearsing those rigs, at least. When the camera does a 360 move around Trinity to make it look like she was twisting in the air? That is Carrie-Anne Moss on the rotisserie rig, although some of it before and after is the stunt double. Carrie-Anne did the wire work, and the stunt double did the dive into the flying shot, dove through the window, and went down the stairs. But if you look closely at Carrie-Anne's feet during the twist, it looks like she's standing and not diving, and that's because she was. She was standing in the rig, between the building and the window.

Video of The Matrix: Trinity escapes

Stahelski: Most action scenes take half a day to three days. In our world, it was taking a week. The dojo scene was over a week.

Boswell: There was a lot of rehearsal for the dojo sparring-program scene. You can actually see Keanu hold the wire when he runs up the post and does the flip backward. You can't see the wire itself, but you can see his hand resting on the wire. His hand is kind of rigid, because he's pressing on the wire to get through the flip. It's such a tricky move, and it doesn't make him look any less badass doing it.

Video of Matrix - Neo vs. morpheus Full 1080p HD

Yuen: The one thing I remember they wanted from day one was what was later called "bullet time." It was just an idea of being able to see around an action. What we remember now as the most iconic bullet-time shots – Neo dodging bullets, Trinity's midair kick – were probably some of the simplest moves in the whole film.

Boswell: I was shown the storyboards where Keanu leans backward and the bullets fly past him, and I was like, "Okay. How the hell are we going to do that on top of a 35-story building?" So I found a portable truss staging system, where you can break it down into pieces to fit it into an elevator to get it to the rooftop. I just had to rig Keanu and get him to lean back into this system, so they could shoot in a way where they didn't see it in the camera.

The other spanner in the works was that Keanu had a problem with his neck, and leaning back put stress on it. So I had a special harness made to give him support on the back of his head. And after bullet time was done on the roof, we had to do it in the studio, where there were 120 still cameras and two motion cameras set up to fire in sequence, to create the illusion of movement, and recreate and match what we did live on the roof. It was quite an ingenious setup.

Stahelski: They came up with a process for bullet time that was a work in progress. Aside from regular shooting, we spent every weekend on a soundstage where we'd do the specific moves that the Wachowskis felt were going to be highlighted with bullet time. We did tests and rehearsals. The effects people would photograph me and the other doubles doing what they were going to have Keanu and the other actors do, and then they'd go back to the drawing board. That took months to dial in.

Boswell: The bullet time shot was always going to be with the actor. That was all Keanu. But we had the stunt doubles do some of the wire work, because that was a strain on his neck. Of course, Keanu wanted to do everything. Sometimes we'd have to tell him, "But you don't have to. We can do a wider shot with the double."

Video of The Matrix Behind The Scenes - Rooftop (1999) - Keanu Reeves Movie HD

Stahelski: For most stunts, you get five takes, maybe ten. But to show that Keanu and the actors were doing their own moves, the Wachowskis didn't want to do a lot of cuts. It wasn't weird to do 20 to 30 takes.

Boswell: The subway fight, oh god. That was lots of wire work, when they did the dive through the air. There's a piece of action Keanu did on the wire, when he's on the ground and then he stands up. I think he did about 40 takes on that, because he wanted it to be so perfect. And it shows in the movie. He had that kind of attention to everything. Hitting the roof of the subway tunnel, coming up from the track, that was tricky, because you had to fly them up to the roof, make it look like an impact without hurting them, drop them, and then catch them before they hit the ground. That was so complicated and such a tricky piece of action to do. I think we had to do that with the doubles, because it was too dangerous.

Video of The Matrix Neo vs Mr. Smith (Subway Fight)

Stahelski: They asked how hard I could land on my head. [Laughs] That was for yanking me through walls and flipping me on my face. Which cheekbone got to hit the ground first. That was nice of them to ask. Which part of my brain could I dent the most, my occipital lobe or the cerebral cortex? [Laughs]

Boswell: The helicopter scene, when we're flying the guys over the city suspended by a cable, that was bloody difficult. Then we had to drop the stunt doubles on a rooftop – how are we going to do that? We can't do it from the helicopter -- it's too unsafe. What if you missed it by even a second? Okay, we're going to have to do it in pieces, from a crane. So we had to build a special crane arm, so we could swing and drop the stuntmen on the lower levels of the roof. There's a part where they drive past a building and you just see the doubles on the rope and they swing around? When you can't see the helicopter? That's when they're on that crane rig.

Video of Matrix (Helicopter Shout out) 4K

Yuen: The first time I saw the film in America was in English, without Chinese subtitles. So even though I worked on the film, I still had trouble understanding all of it.

Stahelski: I was invited to the premiere, and was absolutely blown away. You could feel it in the theater. Everyone lost their s**t.

Boswell: The first time I saw the full movie in the theater, I went, "Holy s**t!" I'm just really happy to have been part of something that changed action in movies forever – the style of fighting, the wire work, the safety standards.

Stahelski: It was really impactful. It changed our careers, it changed the industry – the wire-work aesthetic changed the whole deal. The fact that you can do cool action and make it look beautiful with lighting and camera moves was a whole different concept. If you can't tell by the John Wick movies that I'm influenced by The Matrix, then you're blind. I mean, we are flat-out ripping that off! [Laughs]

The Wachowskis — and I think Steven Spielberg was the predecessor of this, because he would shoot his own action — would tell the story through action. You can learn as much about a guy in an action sequence as you can from him just sitting down and talking. A good director can do both. A good director wants to do both. And that's what The Matrix imprinted on us for the rest of our days.