In February, Zack Snyder, the director of the then-forthcoming Batman v Superman: Dawn of Justice, got testy with his critics. During an appearance on the Hall of Justice podcast, the hosts asked him about his decision to have Superman kill the villain Zod at the end of Man of Steel. “People are always like ‘You changed Superman,’” Snyder said. “If you’re a comic-book fan, you know that I didn’t change Superman ... You know I’m a bit of a comic-book fan, and I always default to the true canon.”

Canon—the established facts and backstory of a fictional world—is a concept common in fan spaces. To discuss anything from Doctor Who to Star Wars to Superman without demonstrating some familiarity with canon is to risk being undermined as a dilettante. So while the reaction to Snyder’s comments was swift and predictably furious, as fans and critics alike argued about the validity of his Superman interpretation and fought over his understanding of comics, few questioned his fundamental embrace of canon as a concept.

With the rise of mass-media intellectual properties and ascendant geek culture, the tendency to treat the original comics, novels, and video games like holy writ has spread out of fan communities and into the larger cultural conversation. Creators and critics alike now are expected to be well-versed in source materials. J.J Abrams’s 2009 Star Trek reboot went to great lengths to establish itself as canonical; the very existence of The Force Awakens spurred a cottage industry of writers to analyze the film’s departures from the Star Wars “expanded universe” it had replaced. A good portion of the Internet firestorm around Batman v Superman has been couched in terms of its fealty or deviation from comics. Canon, in other words, is king, and if you want to talk about anything geek-related, you’d better have your credentials at the ready.

There’s only one problem with true canon: It doesn’t exist. And in an effort to hold people to it, enthusiasts strangle criticism, hamstring creators, and make fan communities far more toxic for everybody.

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Where does canon come from in the first place? The simple answer is love. Fans are people who find intense joy in minute details, from the stitching on a costume to the intricate backstory of a character. The desire to play in fictional worlds created the necessity for distinguishing between “official” work by creators—canon—and the unofficial work of everybody else. There are other sorts of canons of course: The critical canon enfolds art considered to be superior, while the Church canon comprises the rules and beliefs as dictated by Rome. But the canon of geek culture encompasses a strange balance of power. It has its own self-appointed priests, its own heretics, its own endless struggles and outside influences. It’s a metric created by fans, for fans, that nonetheless pays lip service to the supremacy of the creator’s vision. This is canon’s inherent friction: It’s an attempt to lock down and categorize the imaginary creations of other people.

These other people don’t always cooperate. The idea that creators dictate an ineffable and consistent canon has always been a bit of a convenient fiction—storytellers tend to have a looser relationship with their own work, changing details to fit the need of a current story, coming up with ideas they like better, or simply losing track of things. George R. R Martin’s immense and ongoing Song of Ice and Fire saga is a typical case—Martin’s often admitted he needs the help of semi-professional fans to keep it all straight.

Works with multiple successive creative teams are even more ramshackle, as everything established by one author is often cheerfully contradicted by another. (Comics are especially notable for this. One legendary example: Is Hawkman a policeman from an alien planet, or a reincarnated Egyptian prince, or a god, or some combination of the three, or neither?) Engaging with canon thus is an act of personal curation: a chance to play textual games with absent authors, draw quasi-talmudic connections, craft subversive readings, or spin ideas that weave neatly between the lines of primary texts. But the common understanding of canon also could be a ruler: hard, minutely measured, and often used to slap people’s knuckles, which has happened more and more as the loose canons of fan culture have become codified by corporate influences.

Throughout the ’60s and ’70s, DC and Marvel began recruiting a new generation of writers and artists from fan communities. These fans-turned-creators and their successors carried with them an appreciation for canonical minutia and details, as well as a tendency to sneak old ideas into newly official contexts. Not only did the companies find official canons editorially useful for keeping their invented universes straight, but fan audiences also loved them. Multimedia properties like Star Wars and Star Trek soon followed a similar trajectory, drawing from passionate fan bases and instituting official (often contradictory) canons of their own. Companies began selling spinoffs and ancillary guides expounding on official canon, all aimed at dedicated fans. The prevailing illusion was one of cozy intimacy between fan and company, with both equally invested in true canon and the purity of intellectual property.

This proved damaging for all concerned, in part because of the unique setup of fan culture at the time. Science fiction, fantasy, and comics communities were increasingly isolated and marginalized from the 1950s on. All of these genres—comics especially—were considered childish things, and within the cultural mainstream, to declare yourself an adult fan of them demonstrated a fundamental lack of maturity. Socially outcast fans reworked their textual knowledge of comics or science fiction into badges of honor, and as companies awoke to the possibilities of cultivating dedicated fan bases, the mastery of arcane canonical details acquired a certain social and economic cachet.

The addition of corporate canon gave fan communities a clergy, and the more companies catered to that demographic, the more powerful these clergies grew. Fans who claimed to know the most about official canons considered themselves the most important—and they often used their knowledge to both bully those they considered insufficiently serious and to shut down criticism and disagreement. (Among the favored techniques: accuse people of faking an interest, question their dedication to material, demand detailed citations for any contrary opinion.) These fans dedicated themselves to their invented universes and defended them against everybody, including their creators. Media companies soon discovered that their audiences were in a constant state of revolt, particularly when creators tried to alter established “facts.” Newcomers often found the entire business completely impenetrable.

As much of a headache as this was for companies like Marvel or Lucasfilm, it’s worse for anybody attempting to adapt geek media of any kind. Adaptations that the fan clergy perceive as departing from canon—or the ineffable spirit of the work—are often subjected to withering scorn. Leave aside the fact that adaptations must change things while translating between different types of media: The desire for adapted material to follow the spirit of the original is understandable, and there have been some truly terrible adaptations of geek properties over the years, such as The Last Airbender and Jonah Hex. But which original should an adaptation follow? The fact that many of these multimedia properties have multiple, mutually exclusive canons—Star Wars and Star Trek have two, Marvel and DC have several more—makes the entire exercise of calling something “canonical” ridiculous.

Yet many fans demand fealty to canon, so canon shout-outs now abound in media: Consider the regular appearances of popular-but-obscure characters on Arrow and The Flash, images pulled directly from a comics panel in Zack Snyder’s Watchmen, and the interminable digressions of fictional history in Iron Man 2. These intrusions are often called Easter eggs, but they’re closer to dog whistles, and the worst of them are completely inexplicable to anybody walking into an adaptation fresh. The emergence of this style of filmmaking has also led to the rise of the “canon explainer”—a genre of articles that explain references in painstaking detail to the uninitiated. While not inherently a flawed form, their rise creates a codependent relationship with corporate media and established fan communities, leaving enthusiasts to pick up the slack of explaining material that should be covered in the art itself. Worse, these pieces often implicitly hold up source canon—and loyalty to it—as the only thing that matters.

Which leads directly to the near pathological hatred for outside opinion in fan communities. Fans might complain bitterly about adaptations they consider flawed, but many get really angry about criticism of ones they consider canonically faithful. (Take for example the regular, near-hysterical outpourings against anybody who’s less than enthusiastic about Batman v Superman, The Avengers, The Force Awakens, or The Dark Knight.) This reaction also has historical roots: The social dynamics of science fiction, fantasy, and comics fandom have historically made them into ferociously policed boys clubs, with perceived outsiders—often women—subjected to spontaneous canonical inquisitions by the self-declared clergy.

Harassment of this sort is still extremely common: In an example that will ring familiar to many, a friend of mine with a lifelong love of Star Trek once wore a handcrafted costume during Halloween and found herself beset by a man who insisted on quizzing her “to make sure [she] wasn’t a poser.” The gatekeeping impulse goes into overdrive when presented with anybody who critiques beloved material, professionally or otherwise. Here, knowledge of canon becomes a purity test, one virtually designed to be failed. After all, can a critic say anything about the problem with the racialized metaphor in X-Men—such as the fact that in the real world, black people generally don’t shoot lasers from their eyes—unless he or she has been reading the comics for 40 years? Is a critic allowed to grapple with the sexual politics of Game of Thrones without citing the books? If critics come to the material fresh, their opinions are ignored. If they’ve read the comics and are familiar with the books, then it’s demanded that they prove it.

The examples of this behavior online are widespread. They range from the comical—a fan of Batman v Superman accusing the former Batman writer Gerry Conway of not being familiar with the character—to the vicious. The virulent online movement “Gamergate” focused much of its vitriol on critics like Anita Sarkeesian, claiming that since she “wasn’t a gamer,” she wasn’t qualified to discuss sexism in gaming culture. When the former DC editor Janelle Asselin wrote an essay pointing out the implicit sexism of a Teen Titans cover, her criticism was brushed off with dismissive accusations of not being a real fan. In all of these cases, the goal is the same: delegitimize any critique by casting a critic as an outsider—not a real fan—and therefore someone to be either ignored or attacked.

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Can all of this toxicity be laid at the feet of canon? It’s true that all specialized subcultures, from sports to Star Trek, practice their own varieties of gatekeeping and abuse. But the elevation of corporatized canon to scripture in geek culture is a particular issue. Snyder’s appeal to “true canon” isn’t just one seen in comment threads and message boards. When Snyder or Abrams speak about canon, they speak with the weight of Warner Brothers and Disney behind them. Their canon is a fully top-down policy, one that empowers fans as enforcers and sells an endless array of branded special knowledge. The canon is true, and cannot be questioned. Its themes cannot be wrestled with. It cannot be criticized. It must be consumed in its entirety or not at all. And if official canon chokes out casual engagement and deep engagement with stories alike, then it’s best to simply throw it away.

What’s been largely lost over the past decade is the crucial point that these stories are imaginary—they were dreamed up by people, and can be changed, distilled, or subverted by anybody at the drop of a hat. There is no true canonical version of Batman, Superman, Princess Leia, James Kirk, or any other shared characters—only infinite interpretations by an array of creators. Treating them as if they’re carved in stone only reduces them to a flat series of issue numbers, paragraph citations, or official tables. It takes away the joy of personally deciding which version of a character you like, which version of a story you prefer. The truth is that nobody—not the company, not the fans, not even the creator—can dictate the nature of a story to you. Batman v Superman is not canon. Neither is Batman: The Dark Knight Returns, or the current Batman run, or the Star Wars novels, or even the films. The only true canon is personal, and it lives inside your head.