Fantasy author Garth Nix isn’t primarily known for his connection to Dungeons & Dragons, but it’s something geeky journalists can’t stop asking him about. Best known as the author of the Old Kingdom YA novels (such as “Sabriel”, “Lirael”, “Abhorsen”, and many more), Nix has also written everything from children’s picture books to adult short fiction—and articles about Dungeons & Dragons. Nix ran a D&D game throughout high school and carried on as a tabletop role-player from there, and it shows in his upcoming middle-grade novel “We Do Not Welcome Our Ten-Year-Old Overlord”, which follows a group of kids as they multitask between navigating an alien invasion and playing D&D. (An excerpt from the book follows this interview.)

That premise may remind savvy readers of “Stranger Things'” obsession with Dungeons & Dragons, and the title may call to mind a certain quote from “The Simpsons”. In an interview ahead of the book’s October 15th release, Nix told Polygon he didn’t have either of those references in mind when he was writing the book, though he did start out with that title, before he even had a whiff of story attached.

“I actually don’t know where I first heard the phrase,” he says. “It was something that was floating in the aether. […] I’m not a huge ‘Simpsons’ watcher. I mean, like everyone alive, I’ve seen quite a lot of episodes, but I was never a consistent fan.”

Similarly, he’s never watched a complete season of “Stranger Things”. But he has watched the ’80s movies the show evokes for inspiration—and lived the “kids on bikes” life that inspired those movies in the first place.

“Of course those subconscious influences have to be there,” he says. “You don’t necessarily know what your subconscious is drawing upon. I mean, it’s also—totally coincidentally, to me— the 50th anniversary of D&D this year, but that never crossed my mind either. […] Mainly, [10-Year-Old Overlord] comes directly from my own life, and my own D&D-playing life, from when I was 12 and started playing the game, and no one else knew about it.”

The story kicks off in 1975 Canberra, Australia, where Nix grew up. “10-Year-Old Overlord”‘s central kids—12-year-old friends Kim and Bennie, and their respective younger siblings, Eila and Madir—find a metal sphere in the shallows of a neighborhood lake, initially thinking it looks like a severed head. It turns out to be an alien artifact that bonds with Eila and begins communicating with her telepathically. The sphere, which Eila names Aster, exhibits some suspicious behavior, from creating mysterious clouds to killing local animals.

“It’s very much a personal story,” Nix says. “It begins with an event that actually happened to myself and several of my friends—we found something in the lake that we thought was a cut-off head for about 15 minutes. And with some debating—’Should we go look at it?’ ‘No, I don’t want to go look at it.’ ‘You sure it’s a head?’—we did go and look at it, and it was, in fact, a stone with lake weed growing around it that looked like hair.”

The book winds up reflecting Nix’s own D&D fandom, with the kids geeking out over the publication of “The World of Greyhawk” and getting granular about their character builds. Nix even publishes a few pages of maps and notes in the back of the book from his own high school game, all created when he was 15. Where other authors might have replaced D&D in this story with a generic equivalent, Nix says that for him, it had to be the real thing.

“I never even considered making up a game,” he says. “I guess my basic philosophy with fantasy in general is to try and use as much real stuff as you can. If your foundation is as real as possible, then the fantastic elements you put on top will work better. So I didn’t even think about it, to be honest. It’s 1975—what else would they be playing? I guess in a few years, it could have been ‘Empire of the Petal Throne’, or ‘Tunnels & Trolls’, or even ‘Traveller’, a few years later. But it just seemed to me that those kids at that time—that’s what they would have been playing.”

Nix still occasionally runs RPGs, when he can find time. “I’ve been running a game set in the world of my book ‘Angel Mage’, which is kind of ‘The Three Musketeers’ with angelic magic, using the ‘Flashing Blades’ rules, which is another very old game,” he says. “I’ve been running for two players in the UK, two in Adelaide, one in Melbourne, so necessarily online, and just much more difficult. The scheduling is just an absolute nightmare.”

Much as when he was a teenager, he’s much more likely to be the GM of any given game than a player. He says that as a teenager, he just couldn’t find anyone else willing to run a game—but that dynamic probably helped his career in the end.

“I do think I love being a storyteller,” he says. “I love the whole process of creating a cooperative story in role-playing, and it was undeniably a great apprenticeship for being a writer. So I should be grateful to them, perhaps, that they kind of forced me to be the GM.”

Below, read a chapter from “We Do Not Welcome Our Ten-Year-Old Overlord”. At this point in the story, Eila is spending more and more time with the alien sphere, Aster, and her brother Kim and his best friend Bennie are worried. The other members of their D&D group, Theo and Tamara, haven’t been let in on the secret yet.