The battle royale genre is a black hole from which no franchise is safe. Since PlayerUnknown’s Battlegrounds and DayZ popularized the genre, Fortnite’s Battle Royale mode catapulted it into the zeitgeist, Apex Legends proved the format could adapt, and Tetris 99 extended the philosophy beyond shooters, major gaming studios are turning to “last player standing” gameplay hooks in order to build a player base.

As the genre continues to dominate attention, transfixing players with its last-man-standing hook, the origins of the battle royale become blurrier and blurrier. How did we get here? The battle royale genre didn’t start with PlayerUnknown’s Battlegrounds or Minecraft survival mods or The Hunger Games. The seed of the idea — as far as old-fashioned, local library research can determine — lie with a novel that got adapted into a manga that in turn got adapted into a cult classic film starring Beat Takeshi: Battle Royale. But the book has its own origin story, too.

Author Koushun Takami released Battle Royale in 1999, a refined version of a story he submitted to a writing contest in 1997. (He didn’t win.) A year after publication, the novel received official manga and film adaptations, as well as condemnation from the National Diet for its horrific and graphic content.

Takami’s Battle Royale is dark — darker than the murder-heavy games that it inspired. When the novel starts, Japan is under a fascist government that wants to crush any potential rebellion by any means necessary. In order to instill that fear in the citizenry, the government enacts the “Battle Experiment No. 68 Program,” which calls for a group of high school students to be transported to a remote location, given random items and weapons, and thanks to explosive collars latched around their necks, pitted against each other until only one is left alive.

The perverse genius of the dystopian competition’s rules is the obvious seed from which the battle royale craze grew. Game developers cribbed tons of rules and regulations from the story, from growing dead zones that would instantly trigger the explosives in the students’ collars, to the random nature by which students are equipped with starting weaponry. (In the novel, a poor student gets stuck with a boomerang when the program starts. Anyone who’s dropped into Apex Legends and found nothing but helmets and Mozambiques can relate.)

But how did Takami begin to imagine the horrific Battle Experiment No. 68 Program? In a 2009 edition of Battle Royale, the author wrote an interview/afterword hybrid as a kind of goodbye to the mega-popular story. He wanted to say everything he could about his work so that he could finally leave it behind and start on another story. (Sadly, Takami has still not released any new work since Battle Royale.)

Takami originally wanted his story to be a detective horror novel, but couldn’t make the structure work. Like many artists, however, he was able to get inspiration from a somewhat unlikely place: a hallucination brought on by lack of sleep.

I was lying in my futon, half asleep, half awake, and I got the mental image of a teacher from a school drama I saw on TV long ago. He said, “All right class, listen up.” [...] “Now today, I’m going to have you kill each other!” The image of him grinning as he spoke was so vivid, I laughed, but was also terrified. [...] And with just that, I knew I had something to write about.

Battle Royale blossomed out of that mental image. Once Takami knew that the story was going to revolve around classmates killing each other, discussions with his friends revealed to him that he’d basically reimagined the pro wrestling battle royal (or royal rumble, if you watch the WWE.) These matches have been an integral part of professional wrestling entertainment for as long as pro wrestling has existed, and they were (and continue to be) huge affairs, with upwards of 20 combatants entering the ring before being eliminated one by one.

What really interested Takami about this concept was the social aspect of a battle royal; the way former enemies could come together to overcome a superior opponent, and the way that friends and partners would be forced to betray each other for their own glory. This, more than anything else, is what makes the book so horrifying: the fact that the rules necessitated betraying someone important to you in order to ensure your own survival.

Takami struggled with this realization for a while, especially because, as he says in his afterward, he intended for the book about children murdering each other to be a light-hearted romp. Since he was a pro wrestling fan, Takami wanted there to be an air of sportsmanship surrounding the whole affair. But he kept coming back to the element of betrayal, of how there is, in his words, a huge difference between being double-crossed by your friend and pinned for the enjoyment of a crowd, and being double-crossed by your friend and shot dead.

The level of distrust for your fellow man wouldn’t even be comparable. I had arrived at the realization that it wasn’t sportsmanlike at all. And I think it was at that point that it became possible for me to write this story.

His inspirations also extended outside of the ring into real-world post-boom Japan. Takami grew up in the 1960s, when large groups of revolutionaries in Japan fought back against police brutality. After an economic boom, the revolutionary instinct largely vanished, either because of laziness or, again in Takami’s words, because they realized that throwing Molotov cocktails wouldn’t change anything.

This reality, combined with inspirations from his favorite Stephen King novel, 1979’s The Long Walk, about a walking contest organized by a totalitarian government, helped inspire the fascist universe of Battle Royale. This is a world in which “even if everyone were against it, no one could say it out loud. That’s why nothing changes.”

Given everything Takami has said about his story, it seems like a more apt video game adaptation of the original Battle Royale novel would be less like Fortnite, and more like the Danganronpa series: each game in the series features a large group of students forced to murder each other, and the games are built around mistrust and betrayal. Sportsmanship and honor have no place in the world of Danganronpa, in the same way that they have no place in the world of Battle Royale. Sure, the Danganronpa games have built a cult audience, but the series isn’t a worldwide phenomenon like many battle royale games are.

Danganronpa and Fortnite can each serve as representatives for the varied nature of Takami’s influences. From his interests in psychological horror and Stephen King novels, we get the mistrust and intrigue of Danganronpa. From his interest in professional wrestling, we get the sportsmanlike mayhem of Fortnite, PlayerUnknown’s Battlegrounds, and countless others. Though Takami knew he’d have to throw the concept of sportsmanship out the window to give his story emotional weight, game developers don’t really have that same restriction.

That said, up until now there hasn’t been a game that seems in line with Takami’s full vision, a game that truly embodies the spirit of Battle Royale and everything that influenced it. Perhaps the next great battle royale game will have a sort of turncoat mode, where a squad member has a hidden agenda of betrayal and deceit, tearing the team apart from the inside as it attempts to defend itself from outside dangers. You know, kind of like the way the Polygon staff played PUBG that one time.

There’s also a lesson here in why battle royale games that don’t innovate in some way (see Radical Heights and countless others) struggle to find an audience. The last player standing format isn’t enough to engage folks on its own, and Takami knew that. The real genius of Battle Royale is in the way that Takami blended different aspects of his interests and obsessions together, using them like puzzle pieces to create something truly new and horrifying.