"Insurgent" -- the second installment in the series that hits theaters in the United States this week -- will be followed in 2016 and 2017 by two movies made from "Allegiant," the final book in the trilogy.
"My whole life, I've wanted to be a writer and write books, and maybe I thought someday I'll get a book published, and that was kind of as far as my dreams went," she told AFP in an interview.
"The movie stuff ... I didn't even really think about, it's been really exciting and gratifying to see it come to life," added the author, who has had to get used to being the idol of masses of teenage fans.
- 'Hunger Games' parallels -
Roth -- who welcomes comparisons between "Divergent" and similarly dystopian young adult fiction-to-film blockbuster franchise "The Hunger Games" -- is in the middle of the media circus surrounding the Friday release of "Insurgent."
The story follows the fearless Tris, played by Shailene Woodley, who in the first movie learned that she was "divergent" - not fitting into any of the five factions into which post-apocalyptic Chicago has been divided.
Those groupings are Dauntless (the brave), Erudite (the clever), Amity (the peaceful), Abnegation (the selfless) and Candor (the honest). There are also the Factionless -- those not welcome in any faction.
In "Insurgent," Tris -- helped by her love interest Four (played by Britain's Theo James) -- must confront her inner demons as she fights the evil Jeanine (Kate Winslet), determined to wipe out the divergents.
The parallels with "The Hunger Games" franchise are many: a strong central female character, a dystopian future setting divided into groups ruled by an evil central figure, a hunky love interest and quirky sidekicks.
The first "Hunger Games" book was published in 2008, three years before "Divergent."
Some might suggest Roth is following a formula, but she is far from offended by the comparisons.
"I love 'The Hunger Games,' books and movies," she said.
"The best part about it was that those books created a space in the market for stories like mine ... I feel very fortunate that I wrote that story when that space was here."
But she added: "It's a tough comparison, because I have a lot of admiration for those books. So it's a lot to live up to."
- 'Harry Potter' geek -
Roth is also crazy about the world of "Harry Potter," going so far as to call herself a nerd fan of the boy wizard created by British author J.K. Rowling.
"I think a nerd is just someone who really loves something or a lot of things... I've always been a big Harry Potter geek and always loved reading, which of course will get you labeled as a nerd sometimes."
Roth also describes herself as a feminist, but says she doesn't portray women as ideal.
"Certainly they're not perfect ... I like to write about women and to render them as carefully and thoughtfully as possible," she said.
As the "Insurgent" launch rolls on, and the "Allegiant" one gears up for the coming years, the young writer is already working on her post "Divergent" world -- her next work.
"It's set in space... Star Wars-esque, like a space opera. It's about a boy who teams up with someone who's supposed to be his enemy, to achieve their very different objectives of revenge and redemption," Roth said.
She is planning two books, and is hoping for publication in 2017.
"But it depends on how quickly I work and how well it goes," she said.
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