You already get a Star Wars movie every year. Star Trek is coming at you from at least two directions. A good chunk of the Marvel movies are basically space opera. Bigscreen fascination with science fiction and fantasy is nothing new—but now you can add the many flavors of TV network, from legacy broadcast to basic cable to streamers. Forget comic books; somehow, SF/F novels have become Hollywood’s hottest IP.

Some highlights of what may be on its way: Amazon is making Neal Stephenson’s Snow Crash and Larry Niven’s Ringworld, and a show based on Terry Pratchett and Neil Gaiman's Good Omens is in production. Universal is doing Hugh Howey’s Sand, Maggie Stiefvater’s Raven series, Kurt Vonnegut Jr.’s Sirens of Titan (with Community genius Dan Harmon at the helm), and Roger Zelazny’s Lord of Light, a.k.a. the movie that the CIA pretended to be making when they rescued American diplomats from Iran—a story that was itself the basis for the movie Argo. Done yet? Nope! HBO is making Nnedi Okorafor’s Who Fears Death? Netflix is making JG Ballard’s Hello America and Daniel Suarez’s Change Agent. And Lionsgate is making Patrick Rothfuss’ Kingkiller Chronicle series.

Phew.

Sure, some of these shows will never make it out of development; others won’t last a full season. Runaway successes like Game of Thrones and The Handmaid’s Tale make it worth the effort; Hollywood is nothing if not willing to keep doing what already worked. Besides, the saga of Westeros is about to wrap up, and then who'll take the reins of fire?

All those various networks and services have offered up plenty of original sci-fi, too, of course. Stranger Things is the obvious standout there. And I’ll do you a solid and point you at Travelers on Netflix, a wickedly clever time travel show from Canada, due for a second season this year.

Some deeper incentives might be behind the raiding of the science-fiction section, though. Familiar intellectual property has two advantages for a TV network. First, it’s already vetted. An editor with experience in science fiction has already made the sign of the IDIC over it and fired it out of a photon torpedo tube. Its characters, its world, and at least the skeleton of its plot live in the fictional universe.

As a consequence, TV makers don't need tea leaves—they can just look at Bookscan and get a sense of how big their built-in audience is. That’s never certain, and the number of people who read Snow Crash, genius though it is, probably isn’t big enough to turn it into a massive hit. But then again, viewership and ratings don’t have the same importance they once did, especially for streaming services. The Amazons, Hulus, and Netflices of the world are more interested in prestige, in must-subscribe programming, and—as a proxy for those other two things—maybe even in Emmys and glowing press coverage. (Quick counterpoint: Syfy’s The Expanse, likewise based on a successful series of books, hasn’t gotten the same attention or audience—which is too bad; it’s cool.)

Plus, genre often ends up being easier to market than "straight" or more literary drama. Take The Man in the High Castle, based on the Philip K. Dick novel. "What if the Nazis won World War II?" Pow. Now try to find a logline like that with, say, Atlanta.