A new documentary about Ursula K Le Guin shows the late author reflecting on the impact of feminism on her work, revealing that she had been “a woman pretending to think like a man” and that her much-loved Earthsea books “are a total complete bust” as feminist literature.

Le Guin’s first three books about Earthsea centre on the male wizard Ged, with women “either marginal or essentially dependent on men”, according to the author herself. In director Arwen Curry’s forthcoming Worlds of Ursula K Le Guin, which Curry worked on with Le Guin for 10 years, the novelist speaks of how when she started writing, “men were at the centre” of fantasy and admits that “from my own cultural upbringing, I couldn’t go down deep and come up with a woman wizard”.

The third book in the series, The Farthest Shore, was published in 1972. When Le Guin came to write the fourth, which centres on the female character, Tenar, she found it “just wouldn’t go”. It took her another 17 years to work out how to tell Tenar’s story, with the 1990 novel Tehanu.

The trailer for Worlds of Ursula K Le Guin.

“What I’d been doing as a writer was being a woman pretending to think like a man … I had to rethink my entire approach to writing fiction … it was important to think about privilege and power and domination, in terms of gender, which was something science fiction and fantasy had not done,” Le Guin tells Curry. “All I changed is the point of view. All of a sudden we are seeing Earthsea … from the point of view of the powerless.”

Although Le Guin won many awards during her lifetime, the documentary – which will premiere on 10 June at the Sheffield Doc/Fest – reveals her initial struggle to be published. Rejection letters from publishers in the 50s tell her, variously: “You write well and are obviously very erudite. But here you have a book that we feel, regretfully, would be of interest to very few American readers,” and “the basic subject matter and background is so remote that I could not encourage you to recast it from a practical point of view”, and “there would not be a large enough audience for a novel of this kind”.

Le Guin tells Curry: “When I started writing, the basic assumption about fiction was that men were at the centre of it … I don’t know how many times I was told I write well, but, ‘we don’t know quite what you’re doing’. I was beginning to feel a little desperate. If I can’t publish anything except for the occasional poem in a tiny, tiny poetry magazine what am I doing? Am I kidding myself?”

The documentary also features conversations with authors Michael Chabon, David Mitchell and Neil Gaiman, who credits Le Guin’s 1968 novel The Wizard of Earthsea, about a wizard at a magical school, with inspiring Harry Potter.

“I don’t think Harry Potter could have existed without Earthsea. That was the original, the finest and the best,” Gaiman says in the documentary, adding: “What Ursula was having to navigate was the societal prejudices against science fiction, against the fantastic, and against children’s fiction. All of these things were marginalised.”

The documentary makers, who funded the film with a combination of a grant and crowdfunding from more than 3,000 backers, describe Le Guin as an author who “defiantly held her ground on the margin of American letters until the sheer excellence of her work, at long last, forced the mainstream to embrace fantastic literature”. Le Guin died in January 2018, at the age of 88.