How the kapowing of storm troopers became the pop-entertainment universe’s center of financial gravity. David James - ©Lucasfilm 2015

A while back, a friend expressed concern that her son, a ten-year-old, was watching too much My Little Pony. "It's sweet," she said, "but not what I'd choose."

I asked what she would prefer that he watch.

"Well, his dad started him on that new Star Wars cartoon."

That cartoon is Star Wars: Rebels, a retro-now adventure series that harks back to the roguish, hardscrabble feel of the original Star Wars films — but with the look of PS4 cutscenes. Its insurgents wage guerrilla strikes against the Empire: Spaceships explode, stormtroopers get blasted, Imperial middle management gets Force-murdered by Imperial senior management. A captured Jedi gets subjected to what I can only describe as nostalgic torture: There's the orb that Vader used to interrogate Leia in '77! The blue lightning the Emperor fried Luke with! And the spark plug-looking torture rack Han got strapped to in Empire!

Star Wars: Rebels is on the Disney Channel. It's rated TV-Y7 — fine for seven-year-olds.

I'm not here, in Our Week of Star Wars, to say that second graders should be shielded from jolly pop mayhem. Instead, I just want to ask: Why do we agree, today, that this material is appropriate? How did the kapowing of stormtroopers become the pop-entertainment universe's center of financial gravity—and the shared imaginative landscape of billions?

Let's start in the '70s, the decade that Gary Gygax and Dave Arneson first published Dungeons & Dragons rulebooks, illuminating with mathematical clarity the assumption that has long underpinned violent storytelling: that killing makes us better.

A long time ago, in this very galaxy, killing had become dirty work for grown-ups. Once the westerns died, and Vietnam reminded Americans it's not always easy to spot the villains, Hollywood heroes who killed were mostly grim grown-ups: Dirty Harrys, Buford Pussers, Steve McQueens. Filmmakers expected you might want to close your eyes when the bullets hit. The flip side was the kids' movies, where heroic violence was a cornpone joke, as in The Three Musketeers, Burt Reynolds pictures or Roger Moore's James Bonds.

Seventy-seven changed everything. Elvis died, John Wayne was almost there and Hollywood offered three strikingly different takes on the masculine hero: first, Reynolds's high-on-his-own-fumes wiseass, who probably couldn't summarize the plots his cars raced through. The action Hal Needham orchestrated around him was brilliant automotive slapstick — but didn't purport to matter.

Reynolds's smile said, "Ain't this all just a laugh?" The other heroes of '77 played it comic-book straight. Mark Hamill's dreamy naif Luke Skywalker grows great through violence in a manner closer to D&D than the Tolkien and Kurosawa that George Lucas has cited as influences. Meanwhile, Harrison Ford united Reynolds's cocksure disinterest and just enough of that searching hopefulness of Hamill: In the years to come, we would believe that Indiana Jones believes nonsense we knew Ford was barely tolerating.

The seekers and geeks were taking over. Since then, most of our biggest non-R-rated movie and TV fantasy heroes have hewn to Hamill/Ford archetypes: true-believer dreamers who seem to level up as they dispatch bad guys, like Harry Potter, Captain America and Top Gun Tom Cruise.

Or they've been gently cynical heroes-to-be, who carp a little as they're nudged toward their inevitable world-saving and self-improvement: Iron Man, Chris Pratt's Star-Lord, Bill Murray in Ghostbusters, Will Smith in everything.

The early adventure films of Lucas and Spielberg wiped away the dourness of '70s action films and the breezy plotlessness of car-chase movies. Conviction to the fantasy was now as important as the stunt and effects work. Luke versus Vader felt epochal. Even the better Bond movies never seemed important — they were too grown up, in their way, to mistake their stories for anything more than fantastic play. Star Wars encouraged us to believe fantastic play meant everything.

Before Star Wars, our popular culture wasn't cluttered with fantasy heroes. There were comics — Marvel pioneered the self-serious smash-up serial. There were the pulps and old movies I used to skip school to see on TV: Errol Flynn, Ray Harryhausen, Godzilla.

But you had to seek out those thrills, and they had the whiff of trash about them. Just a generation before it came to dominate our culture, fantasy violence was disreputable, a little underground, scruffy and impolite. It wasn't always kid-friendly, and there weren't clear rules covering what was acceptable: Note how the Fangoria-lite bloodiness of the first Indiana Jones pictures contrasts with the gentlemen's fisticuffs of the third, made after the public scolded Lucas and Spielberg for all their heart-ripping and kid-whipping. But the sadism of Temple of Doom or the Daredevil Netflix series differs from that of Star Wars only in tone and degree: They're still about how awesome it might be to kick ass.

You don't hear much today about how stridently the culture resisted the peddling of this stuff to kids, how the clown Geraldo assailed D&D while parents railed against He-Man and G.I. Joe. Evangelicals joined liberals to campaign against a suddenly pervasive media violence that today only seems to bug the latter. Advertisers got spooked, so a weaksauce fretfulness distinguished cartoon ass-kicking from the Lucas-Spielberg gold standard: Vader might hack off Luke's hand, but in syndication the Joes fought a war of Care Bears bloodlessness. Kids were steeped in two varieties of mayhem: the movies' cavalier killing of bad guys, and TV's dishonest, cleaned-up variety, where violence was stripped of consequence.

Seriously, which is less healthy?

The prudes lost the first casualty of the violence war, of course. Now, the kids who laughed at G.I. Joe's tameness demand tougher stuff, for themselves and their own kids, too. Like millennials, they relish the high-stakes play of the Marvel films and the promise of a new Star Wars every year; millions of them have spent lives on the genocidal self-improvement treadmills of Diablo and Fallout.

And they seem to have agreed upon the rules that Lucas and Spielberg were fumbling toward.

There's a generational consensus: Young people's fantasy violence should be escapist, suspenseful, sometimes funny, full of passionate conviction about its own mythology, populated with dreamers and nice-guy scoundrels, and it should always be un-shy about whether the bad guys are dying. (Even the Fast & Furious movies follow these rules.) But that violence should never be too grotesque, bloody or — even worse — flamboyantly comic. Outrage over Temple of Doom pales before outrage over the cartoonish risibility of The Kingdom of the Crystal Skull.

That's how Jedi-torture is now TV-Y7. That's the baseline, the kids' stuff, pew-pew as it should be. A couple of hours later, though, the grown-ups might watch something less nostalgic and more adult, something less beholden to those rules — Game of Thrones, maybe.

The treat has become the staple, the underculture has become the overculture, and now it's the cartoons about ponies that parents aren't sure about. Once he gets hooked on Star Wars, my friend's ten-year-old will never pass without the chance to watch heroes kill — and be reminded that the killing is both good fun and of urgent importance.