With more than two decades in the business, Brett Chan has racked up quite the résumé as both a stunt performer and a coordinator. On the small screen alone he has dozens of credits from superhero dramas “Arrow” and “Supergirl,” to Netflix’s “Altered Carbon.” Now, he is responsible for the stunts on a quartet of high-adrenaline series: TNT’s “Snowpiercer,” WarnerMedia’s “Warrior,” the CW’s “Kung Fu,” and the upcoming “Halo” for Paramount Plus.

How does a character’s backstory affect the kind of fight style you create for them, especially on a show like “Snowpiercer” where people from all walks of life are crammed on that train?

It’s basically characters first, and then you have to elaborate from there. Daveed Diggs’ [character Andre Layton] was an ex-police officer, and so was [Mickey Sumner’s Bess] Till, but they both have very different backgrounds in terms of what their positions were in the police force. [Layton] had been on the force for a little bit longer, so he had a little bit more of a street toughness to him. I tried to give them a little bit more adeptness because police do some basic self defense, gun disarms and how to deal with situations with multiple people or when you’re trying to keep a person [subdued]. It’s always harder to be police officer because you can’t just hit people, you always have to try and and incapacitate them by not striking at them, but at the same time keeping yourself safe. Neither Till nor [Layton] had any martial arts training. The Jackboots were trained military guys — soldier types — so we gave them a standard basic etiquette about how they move with their weapons and we gave them a little more regimented look. They had a definite order about they move in formation, and you have to because if you don’t and one side falters, then the line gets overrun and they can pull you over.

Between Season 1 and Season 2 of shows like “Warrior” and “Snowpiercer,” did you have time to get in and train with any actors, or did they have to rely on muscle memory?

If anything the actors came in more gung ho for Season 2: They loved the stunt team training room and spent more time in there than anywhere else. As more actors joined the “[Warrior”] cast in Season 2, it was more about trying to get them out of the stunt training room. Many of our stunt team remain very close with many of the actors. When Season 3 got renewed there was not any doubt that everyone would do whatever they needed to do in order to be a part of that season. It is an anomaly of a show and if you ever get to work on one like this in terms of the people and content of the project, you are lucky. It is one in a million. [Between seasons of “Snowpiercer”] there isn’t really time to do anything. It’s really up to the actors themselves. Mickey, in her spare time when she wasn’t filming, was training [such as in] jujitsu. It was on her own time. She just wants to train and kick butt — and she wants to be able to show women empowerment, that women don’t need to be saved by men all the time; they can have their own collective of how they survive, especially in that type of climate, where you have to be a little sneakier. She wanted to look like she was better at it, and she was really good and she picked it up really fast. We can definitely give her moves to make it look like she’s a fighter. And we always paired her with a really good dance partner, per se, so she can showcase what she’s doing.

How does the train setting on “Snowpiercer” inform the scope of what you can accomplish in any given stunt sequence?

It can’t be all martial arts. And we have cots in it and we’re dealing with extras. You’ve got to fill the train; you can’t have a car with 50 people and they’re all stunt guys. We have to be really cognizant of that, but we still have to make it look chaotic. We have to keep the action mitigated a certain way so that we can keep our actors safe and keep everyone else around them safe at the same time. I’ll either be able to choreograph on the actual train booth, depending on if they’re shooting or not. If not, then I’ll go tape out the dimensions of it and use boxes and choreograph everything in there. And it definitely limits what you can do and where you can go because the train walls aren’t all solid. Because we have to be able to take the walls off and on and move really fast between shots, that means we can’t always bang against the train walls or they’ll fall and hurt people.

Do you have leeway to have walls moved if you need a bit more room for something special?

They built some trains to be like that, like the Night Car: it’s supposed to be like a giant, two-level thing and it’s wider. But it’s definitely confining and it limits the weapons you can use because if you start putting long weapons in there and you’re swinging them around, you’re hitting people behind you and in front of you. But we’ve had no injuries!

The second season finale had an unexpected dog attack stunt. How complicated was that to pull off, given everything you’ve already talked about as limitations?

We used the actual trainer to be the person the dog attacks because he knows that person already. A dog comes on set, no one’s going to touch him, no one’s allowed to pet him, [there’s] no, “Oh you’re so cute!” You can’t do that because the dog’s got to keep the focus. We keep all things off the set that don’t need to be there because that changes the parameter of things, too.

What sequence did you feel was the most complicated to choreograph and then successfully achieve on the day of production on Season 2 of “Warrior”?

Episode 205’s Zing vs. Li Yong fight and the Episode 209 riot sequence with the individual fights were the most difficult because of logistics involved due to the time we had. We were shooting four episodes at once and I was action directing all of them while still choreographing and doing other work for them. Additionally I was in development for Episode 6 simultaneously. Episode 205’s saving grace was director Loni Peristere. He gave me full control to go to town, allowing me to time manage. He was extremely collaborative. For Episode 209, director Denny Gordon was also extremely collaborative and was a large reason I was able to execute such a difficult sequence. If I had to pick one fight that was the most complicated it would definitely be the riot with the individual fights in Episode 209.

When you have characters like Ah Sahm, who are martial arts experts when they are introduced, what is your philosophy about “topping” the fights and sequences, to continuously show off more of those characters’ skills?

I don’t know if it is just because they are cool fights or needing to “top a fight,” but more of that I think it all comes down to the story and the characters. Really, a fight is just a fight — but if you give it the story and individual characteristics associated with each character at that moment in time, the motivation for the fight becomes more meaningful and has more impact. As storylines changed in Season 2, so did our fight sequences.

How different was experience on “Kung Fu,” in which Olivia Liang, who plays the lead, had no martial arts training before the show but whose character needed to look like an expert?

Even after 10 years, you won’t even really be really that good in a stylistic martial art, and this is specifically stylistic. I said, “They need a little bit of martial arts training, give me eight weeks to train them.” But they gave me this girl who had no martial arts training and five days to to train her. None of the leads had martial arts training. But when they showed up, all they did was train. Olivia said, “I don’t care, I want to train Saturdays, Sundays.” We trained four to six hours a day. She has a dance background so she did fantastic, and she’s just getting better and better.

How does the mysticism element of “Kung Fu” affect what you are creating?

The show was never meant to be “Crouching Tiger, Hidden Dragon.” “Crouching Tiger, Hidden Dragon” has its audience has its genre, and it’s fantastic, but Christina [M. Kim], the showrunner, basically said, “Let’s ground it.” So, it was about keeping the kung fu grounded into daily fighting, but keeping the flair of the styles. We pick her movements depends on the style. Tiger is a very aggressive style, while crane is not. So you see a lot of crane, but when she’s angry, you’ll see the tiger come out. And then we start blending the two together, which starts leveling off her emotional levels. We tried giving that purpose to everybody.