We talk to Derek Richardson, the funny and unassuming co-star of new Charlie Sheen comedy 'Anger Management' about his most famous role to date and what it’s like to work with his most infamous co-star.

If Derek Richardson’s face isn’t instantly recognisable to you, there’s another part of his person that may be, especially to horror movie afficiandos.

Richardson very memorably had his Achilles tendon severed in one of the most gruesome film scenes of all time in slasher movie 'Hostel' and it’s his role as Josh, a gullible and trusting young American tourist for which he’s still most recognised. Although, that could change very soon for the co-star of new Charlie Sheen comedy 'Anger Management.'

"I think most people, yeah definitely, see me, remember me from that, but they don’t remember my character, they’re just like, 'how are your legs?' I’ve had so many people come up to me in the store, or like wherever, at the grocery store, years later and be like 'how’s your Achilles man?' That’s hilarious."

Richardson’s skill at portraying characters who are a little naïve or unworldly, has seen him cast in roles such as young Lloyd in 'Dumb and Dumberer: When Harry Met Lloyd' (the role originated in 'Dumb and Dumber' by Jeff Daniels).

"I’ve definitely played characters like that, but those characters are kind of fun to play too, because you know everything’s sort of new to them and you get bigger reactions than a normal person.

"The stakes are always higher for those characters."

The problem with gaining a reputation, as the go-to actor for the character who’s not the sharpest tool in the shed is there’s a risk of being typecast.

"I think I definitely can easily play naïve, but I think it’s just sometimes you get caught up doing that and then you find that, you can do it and then you find that those parts keep coming."

Richardson, who’s previously had roles on TV series 'Men In Trees' and 'Felicity', is a laid back kind of guy, unlike his 'Anger Management' alter ego, the neurotic and strangely pacifistic Nolan, a member of the anger management therapy group which Charlie Sheen’s character oversees.

Nolan’s a man with an unusual complaint for someone undergoing anger management therapy; he isn’t so much angry, as attracted to anger. It’s not a frame of mind that Richardson can relate to, saying, "I don’t know if I really want to be surrounded by a bunch of angry people", but he reveals the source of the character was actually based on the show’s creator Bruce Helford.

"When I first met him I was like 'hey what is the deal with this guy' and he was like 'oh actually it’s me'."

Helford explained that the inspiration for Nolan was his own inability to experience anger, and his habit of seeking out angry woman and living through their rage.

"I was like 'Ok! All right!' so that’s sort of I guess how the character came about. And it’s still evolving.

"Throughout the series Charlie’s constantly either trying to get him angry to overcome this or trying to steer him in the direction of being with someone who’s not crazy. I think there’s an episode coming up where he ends up being unsuccessful with that because I end up being with another crazy woman, so it’s like this pattern of mine."

While Richardson’s co-star Charlie Sheen has gone through some tumultuous times these past few years in his personal and professional life, Richardson says the 'Anger Management' set feels like a family, and that’s mostly due to Sheen’s influence.

"It’s funny, it’s like when you’re at the set he knows everybody, he’s worked with all the people for like 20 years and so he has this like family that he brings with him every show he does, it’s really great to see."

That family atmosphere extends to his real life family – dad Martin Sheen plays Charlie’s father on the show, and ex-wife Denise Richards is even set to appear.

"His dad plays his dad on the show and they were so great together, I mean it’s so great to see a father/son getting to work together in this really fun environment. And then his dad apparently, signed on, if the show gets picked up he’s going to be, play his father, on a bunch of episodes. You get Martin Sheen on there and Charlie Sheen, who knows, Emilio could show up," Richardson jokes.

"It’s really cool to see, and Denise Richards did an episode, so at one point you’re kind of watching this couple that’s not together anymore right, but their kids are there watching them and I think it’s kind of cool to be able to see this couple that are divorced now but still maintain a good relationship.

"It’s good, because it’s like, that just doesn’t happen all the time!"

'Anger Management' airs on cable network FX in the U.S. and is on the cusp of being renewed for a further 90 episodes, a massive commitment but one that Richardson says he and Sheen are ready for.

"That’s the thing, I think for him is that he needs to work and when you sign up for 90 episodes you’re going to be working for a while, and I think for him to remain, for anyone really to keep sane, you kind of want to be working, for him I think it’s more important, he just loves it, and he’s great at it.

"If it wasn’t for him we wouldn’t even have the show, you know, he’s sort of the leader of the show."

If 'Anger Management' gets the green light for a new season, Richardson could find himself pretty busy for quite some time to come, so what’s next on the agenda when he finally finds some free time? Visiting New Zealand of course!

"My parents have been there, my two sisters lived there for each a year and six months. I think my parents have visited three times, so whenever I go home the place is littered with family albums of New Zealand and I’m not part of them, so I’d love to go. Actually I have two other brothers, I think they’ve also been too, so it’s just like 'why have I not been'?

"It looks amazing, like they just love it. I’ve just got to get on that 14 or 15 hour plane flight. It’s definitely on my list to do, it’ll be happening in the next few years."