The 33-year-old English actress talked about Season 6 of the HBO series Tuesday on Jimmy Kimmel Live. Dormer said the show won't egregiously contradict the books, despite author George R.R. Martin's continued delays.
"I think [series creators] David [Benioff] and Dan [Weiss] have it covered," she said. "I mean, it's fresh, clean snow for all of us ... Maybe A to B, they go off on slightly different tangents, but B is still B."
"[David and Dan] sat down and had a big pow wow with George a couple years ago in case of this eventuality," she shared. "You know, George is a producer on the show so ... I think they're all on the same page."
Game of Thrones is based on Martin's A Song of Ice and Fire book series, with Season 6 to pull from books 4, 5 and 6. The author announced he has yet to finish book 6, The Winds of Winter, last week, more than four years after book 5, A Dance with Dragons, was published.
"Believe me, it gave me no pleasure to type those words," Martin wrote on his blog. "You're disappointed, and you're not alone ... When delivery will be, I can't say. I am not going to set another deadline for myself to trip over ... It will be done when it's done."
Game of Thrones, meanwhile, has finished filming Season 6, which will premiere in April. Dormer shot most of her scenes in Spain, leading some to believe Margaery escapes her imprisonment in King's Landing. She previously told James Corden that Cersei Lannister (Lena Headey) is "the least" of her character's problems in the new season.