Ritchie Coster is just as much in the dark about “True Detective” as the rest of us. Even though he plays Austin Chessani, the corrupt, often-inebriated mayor of Vinci, Calif., in HBO’s hard-boiled drama, the 48-year-old London-born actor was given only the first three scripts when he signed on for the series. Beyond that, he saw only the scenes in which his character appears. “A lot about it was a mystery,” Mr. Coster said. “I don’t want to say they were being obtuse, but it was the most secrecy I’ve ever encountered.”
That’s saying something, considering Mr. Coster has worked on such closely guarded projects as “The Dark Knight” and “The Blacklist.” Mr. Coster spoke about playing a drunk, doing American accents and getting typecast as a villain. These are edited excerpts of the conversation.
Did you base the character of Mayor Chessani on any politicians in particular?
I did watch a ton of California politicians on YouTube. They were all interesting for various reasons, but none of them seemed to do the job. He’s a very specific type — he’s drunk all the time. I couldn’t find anyone similar on YouTube, so mostly he just popped out of my imagination.
What’s the secret to playing a convincing drunk?
It’s kind of a truism among actors — I remember being told this when I was training — that the way to appear drunk is to try and be sober. It does make sense. You’re always trying to speak properly, stand up straight, keep your act together. So when you’re acting it, you put a little extra pronunciation on the words, a little more deliberation with the gestures, try to keep your eyes wide open.
Were you worried about going over the top?
I was very scared about going too far. Acting drunk is a tricky one. You’re skating on thin ice. You’re in danger of looking like a stagey drunk. I had to rely on the director to tell me if I could go further. I had this dark fantasy in my head that everyone else was doing beautiful, serious, nuanced work, and along comes the big British ham to screw up the whole thing. I haven’t watched it yet — I’m saving it for a binge watch. So I’m not entirely too sure that didn’t happen.
So what were actually drinking?
Just water.
Did you stay in character between takes?
I try to do that every job I do, and it lasts about 17 minutes. I get bored, or I see something shiny and all of a sudden I’m myself again.
Is it fun to play such a sleazy character?
Yes. He’s not as bad as the characters I usually play. I often play the bad guy — a terrorist or a serial killer. This guy’s a drunk mayor. That’s pretty gentle on my scale.
Do you get offended that you’re so often cast as villains?
I don’t know what it is. I’ve got this Irish potato face. I bridle against it sometimes, because I’d love to play the lead in a romantic comedy. But I have to poke myself sharply and remind myself it’s work. Who’s to complain, because those roles are always so much fun?
Was there a specific regional dialect you were going for?
I was doing a standard American accent, perhaps opened up a little bit for the West Coast. I’ve played Russians, Afghans, and Chechens, but far and away the hardest one to get is the American accent. I’ve lived here for 20 years, and I grew up on Americana. It’s a sound I’m used to hearing, but for many years, it eluded me. Chessani’s accent was a hell of a lot of hard work.
You’ve played so many American characters. Are people surprised to learn you’re British?
Every now and again, that happens, and it makes my year.
Do you strive to be a physical chameleon as well?
Absolutely. When I’m feeling cynical about myself, I call myself a facial-hair actor. I change my facial-hair configuration for every role. But when I’m a little more optimistic about myself, I grant that it’s a little more difficult than that. I take pride in it. I think it’s important. Otherwise you’re just a talking head.
You worked with another very stylized writer, David Milch, on HBO’s short-lived horse racing drama “Luck.” How does his dialogue compare with Nic Pizzolatto’s on “True Detective”?
I’ve got a worm’s-eye view, but the approach is the same. When you get a line from Milch or Nic, you go, “Well, nobody’s ever spoken like that. How am I going to say that?” Sometimes all you can do it try to get the intention right, close your eyes, lay back, think of England and give it your best shot. It’s invariably well-written, so the rhythm’s going to establish itself.
Were you disappointed when “Luck” was suddenly canceled because horses had died on the set?
It was hard. We were a tight group, and we were all proud of what we were doing. It was much more than a job. It was heartbreaking for everyone, and some people still feel the pain of it. But to tell you the truth, it was inevitable that was going to happen, just because of the nature of horse racing. Horses die. It’s an uncomfortable truth. It happened sooner rather than later.
There are portraits of Mayor Chessani all over his mansion. Were you able to keep any?
I wish I could’ve. There are also photographs of me with every recent president they worked really hard to create. There’s a great one right behind my desk of me with Bush the younger, and our arms are around each other. I wanted that so badly, ironically speaking of course.
Expectations were so high for Season 2 of “True Detective.” Have you tried to shield yourself from the reaction?
I’ve tried, because it doesn’t do me any good. If the response is positive, then I’m going to get smug. And if it’s negative, I’ll be filled with self-recrimination. But it’s hard to shield yourself.