George R.R. Martin has a message for screenwriters who think they can improve on already excellent source material: You know nothing.

Martin, the author of the "A Song of Ice and Fire" books adapted into the "Game of Thrones" TV series, penned a blog post about how literary adaptations are almost always inferior to the source material due to screenwriters making unnecessary changes.

"Everywhere you look, there are more screenwriters and producers eager to take great stories and 'make them their own,'" Martin wrote. "...No matter how major a writer it is, no matter how great the book, there always seems to be someone on hand who thinks he can do better, eager to take the story and 'improve' on it."

He continued, "'The book is the book, the film is the film,' they will tell you, as if they were saying something profound. Then they make the story their own. They never make it better, though. Nine hundred ninety-nine times out of a thousand, they make it worse."

But Martin went on to praise what he feels is a bright spot in the world of book adaptations: "Shogun," based on the James Clavell novel. He described the series as a "really good adaptation of a really good book," something he argued only happens "once in a while."

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The author's remarks were notable given his own work was adapted into a television series that made many changes to the source material and had a hugely controversial ending. However, he never mentioned "Game of Thrones" in the blog. Martin serves as producer on the "Game of Thrones" prequel series "House of the Dragon."

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During a discussion with fellow author Neil Gaiman in 2022 about book adaptations, Martin made the distinction between "legitimate" and "illegitimate" changes, according to Variety. As an example of the latter, he remembered writing an episode of "The Twilight Zone" that adapted Roger Zelazny's "The Last Defender of Camelot" and being forced by CBS to add an "ordinary person" into the story who "tags along."

"I was new to Hollywood," Martin said, per Variety. "I didn't say, 'You're (expletive) morons.'"

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In his blog, Martin wrote that "very little has changed" since he made these comments almost two years ago. "If anything, things have gotten worse," he said.

Martin's 2018 novel "Fire & Blood" serves as source material for HBO's "House of the Dragon." In its first season, the show made numerous changes to the book, but Martin has said there's one area where the series improved on his writing: the character of King Viserys Targaryen, played by Paddy Considine.

"The character (Considine) created (with Ryan and Sara and Ti and the rest of our writers) for the show is so much more powerful and tragic and fully-fleshed than my own version in 'FIRE & BLOOD' that I am half tempted to go back and rip up those chapters and rewrite the whole history of his reign," Martin wrote in 2022.

Martin remains at work on the long-delayed next "A Song of Ice and Fire" novel, "The Winds of Winter." He has said the ending of his book series will differ from the TV adaptation.

"Yes, some of the things you saw on HBO in 'Game of Thrones' you will also see in 'The Winds of Winter' (though maybe not in quite the same ways) … but much of the rest will be quite different," he wrote in 2022. "And really, when you think about it, this was inevitable. The novels are much bigger and much much more complex than the series. Certain things that happened on HBO will not happen in the books. And vice versa."