Game Of Thrones star Natalie Dormer has said it’s “weird” to hear herself as the voice of an alien doctor in a new video game.

She has swapped the cruel Westeros winters and her brunette beauty as Margaery Tyrell for blue skin and outer space as Asari Dr Lexi T’perro in the latest Mass Effect game, Andromeda.

Gethin Anthony, who played Renly Baratheon in the popular fantasy series, will also be featuring, playing the voice of Gil.

“I had a moment when (his) voice came in over across my cans,” Natalie said.

“It’s kind of a weird one hearing Renly Baratheon and Margaery Tyrell in different guises.”

Dr Lexi’s job is to wake the player from a 600-year sleep, transport them to the Tempest spaceship and look after them throughout the game as they join a mission to explore and colonise the Andromeda galaxy.

On the best part of the role, Natalie said: “She (Dr Lexi) tries to walk the line of professional doctor, but sometimes she tips over it.

“She’s got some great wry lines and dry humour in there.”

Developer BioWare’s creative director Mac Walters described Dr Lexi as a complex and human character who even hints at the possibility of romance.

“Her whole job is to analyse people around her, but at the same time she has her own things that she’s dealing with,” he said.

“We want to create characters who seem like their lives are going on, even when the players aren’t around.”

Caroline Livingstone, the company’s voiceover producer, added: “I always think of VO (voice over) as the sprinkling on the sundae… Those characters are already developed and then we come in with the voice and everything sort of blends together.”

Mass Effect: Andromeda is available in the UK from March 23 on Xbox One, PlayStation 4 and Origin for PC.