If you want matter-of-fact, speak to Natalie Dormer.

Recently offering up a few choice words for those who dared to criticise the prolific sex and violence in Game Of Thrones ("If you don't like it, don't watch it"), the British actress is not one for fuss.

And for those in fear of her latest film, supernatural thriller The Forest, her approach is no less pragmatic.

"Just stick your fingers in your ears if it all gets a bit too much!"

Poised, the 34-year-old adds: "I love a good psychological thriller. I like the odd horror movie, but I'm not a horror fanatic. I don't normally get a kick out of being scared, but I like really good film-making, irrelevant of genre."

Taking its inspiration from the real-life Aokigahara forest, situated at the northwest base of Japan's Mount Fuji, The Forest tells the story of Sara (Dormer), an American woman who journeys to the culture marker following the disappearance of her twin sister Jess (also Dormer).

Helped by handsome travel journalist Aiden (Taylor Kinney of Chicago Fire fame), the task seems clear-cut - but the forest's palpable beauty is misleading.

Shrouded with a history of violence, paranormal activity and suicide, Sara is faced with the angry and tormented souls of the dead, and with malevolent spirits lying in wait at every turn, it soon becomes a battle to save herself - as well as her sibling.

"I loved the way it plays out," Dormer says of her attraction to director Jason Zada's 'non slash-and-grab' script.

"It has the thrill ride and it has the bumps and the scares, but there's an emotional intelligence and statement about the inner self too.

"That's what really attracted me on a psychological level - this question of what is strength and facing your own demons, because we all have baggage."

Dormer is known for taking on complex, often tough, female characters - from her breakthrough as Anne Boleyn in racy, historical fiction series The Tudors, to Margaery Tyrell in the aforementioned Game Of Thrones and Cressida in dystopian hit The Hunger Games: Mockingjay Part 1 and 2. Having half her head shaved for the latter, she's not one to shy away from artistic license, either.

Throwing herself into the demands of The Forest, the Reading-born star embraced her character's decent into madness, describing the process as "incredibly liberating".

She explains: "The best gigs do that: when you can be physically liberated, as well as emotionally - from rolling around in mud and being slowly broken down to blood, gore and lack of make-up.

"My make-up artist just stopped covering up the bags under my eyes. It was a gift because we shot pretty much in chronological order, which never happens, so it really helped with the continuity of the breakdown and mess I become."

Sat opposite the preened blonde today, complete with coiffed up-do and those feline eyes, it's hard to imagine her running around a grubby Serbian forest (filming in Aokigahara is no longer permitted), but Dormer is a force to be reckoned with.

Fearless and unapologetic, her sharp wit is intimidating at times and, in a sense, admirable; her business-like handshake a stark reminder that she's here to do a job.

Is there anything she wouldn't do for her craft?

"Not off the top of my head," she retorts, breaking a smile. "But maybe put me in the situation and I'll find out.

"I am quite a physical person and acting is quite a physical job; I think people overlook that fact."

In addition to flexing her acting muscles, she is excited to have recently co-written her first script with director - and her fiance - Anthony Byrne.

Set to start shooting during the first half of this year, the psychological indie thriller, titled In Darkness, is set in London and will star Dormer alongside Emily Ratajkowski, Ed Skrein and Stacy Martin.

Although enjoyable, she confesses that the writing process was a steep learning curve.

"As an actor, it's really healthy to take a step back and not just be looking at it - you know, an actor has to be quite egocentric about their character, but to have this experience as a writer, to be looking at the overall art of a screenplay, was a really interesting experience for me," she adds.

And with a starring role alongside Harrison Ford and Anthony Hopkins in Official Secrets, the long-mooted espionage film about the Observer's reporting of the GCHQ bugging scandal in 2003, in the line-up too, Dormer looks set for a busy year.

Does she ever worry about new projects matching the success of her defining mega hits?

"I don't think you can beat The Hunger Games or Game Of Thrones. They are cultural phenomenons that both redefined the entertainment industry in different ways, and I am incredibly proud to be a part of those. They're two families that I will always be a member of.

"2016, for me, is much more about independent projects and smaller budgeted roles. You always want to do something new; you always want to do what you just didn't do, so the beauty for me is always shaking it up and doing something different.

"I'm very excited about it all," she concludes, appearing settled. "No long skirts for a while, and no running around in mud for a while, either."

:: The Forest is in cinemas now