Anyone interested in an accurate narrative about the famous battle of Thermopylae, in which three hundred Spartans (along with some Hellenic allies) fended off a huge invading Persian force in a narrow pass for several days in 480 B.C., is advised to look elsewhere. This is the video game version of the battle, or more properly a glistening cinematic adaptation of Frank Miller’s graphic novel about it. But certainly the video game can’t be far behind. And it will probably be pretty good.

That’s more than can be said of the movie, though. “300” is an adolescent boy’s dream, a wildly flamboyant, visually opulent macho extravaganza that’s as subtle as an opera but without any good arias. With everything heightened and exaggerated to a wacky degree, the result is even more ridiculous than the beefcake-happy sword-and-toga pictures that the Italians churned out with the like of Steve Reeves in the sixties. But it will doubtlessly be taken much more seriously because of its supposed artistry in employing the “Sin City” formula of situating real performers within computer-fabricated settings that make every shot look like a panel from a comic book. The striking visuals, however, quickly pale in the face of the ludicrously overwrought storytelling, laughable dialogue and grotesque perversion of the historical record.

Let’s deal with the last matter first. It goes without saying that the script, aside from a throwaway comment about an early Persian attack under King Darius, utterly ignores the political and military context of the battle, as well as topographical and strategic realities. (The most notable examples would be the hilariously oversized geographical settings and the complete dismissal of what’s known about Spartan hoplite tactics. Sure, it’s more photogenic to show the soldiers’ well-muscled torsos and legs rippling during the fight scenes, and clashing one-on-one—or more often, one-on-many—with their foes, but the fact is that the men would have been well-armored in the front, protected by much more than just helmet and shield, and would have maintained a firm, rigid line, a wall of metal and spears.) Instead the movie is, quite simply, nothing more than an orgy of over-the-top action, pure and simple, filled with lopped-off limbs, slow-mo decapitations and generous spurts of blood and gore. The grandiose mayhem is interrupted by extended bouts of locker-room style posturing among the soldiers, lots of bellowing (mostly from Spartan King Leonidas, played by Gerard Butler) about freedom and manliness, and very tedious political jockeying back home between Leonidas’ supportive wife Gorgo (Lena Headey) and the slimy traitor Theron (Dominic West).

The presentation of the two sides of the conflict is particularly goofy. The Persians are depicted as monsters of tyranny; and not only does their army contain elephants, rhinoceroses and one Cyclops-like giant (utterly absurd, all), but their king Xerxes (Rodrigo Santoro) camps it up like a refugee from a road company of “The Rocky Horror Picture Show.” But the Spartans come off even more ridiculous to anyone who knows anything about their real regime. One truth about their state—the fact that they killed infants deemed physically unfit—is retained, and some of the best-known lines about them (“Come back with your shield or on it,” “Then we will fight in the shade”) show up, too. But set aside the fact that Leonidas’ mission was authorized—indeed, ordered—by the Spartan government, not something “unofficial” (as it’s portrayed here, making the whole Gorgo-Theron subplot a bad invention), and you’re still stuck with a pile of absurdities. The ephors were elected officials, not some strange community of deformed, oracular monks. Though Leonidas dismisses the Athenians as “boy-lovers,” it’s the Spartan society that was rife with homoeroticism. And despite all the king’s talk of freedom, the Spartans were easily the most brutal slave-owning community in all of Greece; it wasn’t giant wolves they hunted and killed (as young Leonidas is shown doing here)—it was their own helots, or state slaves. Nor was Ephialtes, who eventually showed the Persians a pass that allowed them to attack the Greeks from the rear, the hideously deformed son of a Spartan couple who turned traitor after being rebuffed by Leonidas; he was just a typical turncoat in it for the money.

But enough of such historical points, which admirers of “300” would undoubtedly dismiss as pedantic nitpicking. This movie isn’t intended to educate, but to entertain—mindlessly—and Frank Miller was certainly entitled to edit, alter and add to the actual Thermopylae story however he chose. The problem is that his changes reduce the tale to cartoonish bluster, macho posturing, gargoyle-like imagery and gung-ho goofiness rather than locating any depth or real courage in it. It certainly gets the “mindless” part of the equation right, but proves much less successful with the entertainment quotient.

And given director Zack Snyder’s emptily rip-roaring approach, the cast has little to do but pose and declaim. Butler comes off worst; delivering almost all his lines in stentorian tones while strutting around with chest puffed out, he makes Leonidas into a pompous windbag. Headey, as the only female in view, proves a welcome diversion whenever she appears even if Gorgo’s plot thread is just dull political maneuvering, while West is so tediously malevolent as her opponent that one regrets he doesn’t have a moustache to twirl. And Santoro’s eye-rolling turn is deeply embarrassing. The other Spartan gentlemen on hand get to display their buff bods, but that’s about it. In view of the heavy dose of CGI involved in a film like “300,” it’s difficult to assess the contributions of individual craftspeople like cinematographer Larry Fong and production designer James Bissell. The army of visual effects artists supervised by Chris Watts are probably more important than either of the armies on the screen. But whoever did what, the result is certainly faithful to the look of Miller’s books—which was clearly the intent. One can, however, evaluate Tyler Bates’ background score, which pounds away as relentlessly as the action it accompanies. Whether that’s good or bad is for your bleeding ears to decide.

Fanboys may embrace its wanton carnage, he-man heroics and bombastic dialogue, but “300” really belongs on a PlayStation rather than in a theatre. As for Thermopylae, if you really want to understand it, read Paul Cartledge’s recent book—none of Miller’s artwork, but lots of good scholarship. Or just go back and read Herodotus. His narrative is a lot more fun than this movie.