We all felt relieved when the Justice League movie was put on ice, maybe for good. After all, everything we'd heard about the movie's storyline sounded hokey and convoluted, with way too many random plots from the comics. (Not to mention the kiddie cast.) But putting together a JLA that doesn't feel scattershot would be a massive challenge for any writer. Here are some ideas for making it work.
First, and most importantly, keep it simple. You've got seven heroes and at least one villain. Each one of those characters has enough backstory for a hundred movies. But remember that each of these characters started out with a simple concept, before the comic books added decades of sprawl. A superpowered alien raised in Kansas. A guy who runs super-fast. An Amazon princess. Etc.
We don't need to know that there has been more than one super-fast running guy called the Flash. (Not to mention Wonder Woman's backstory. Was her mom Wonder Woman before her, back during World War II? Or was that the Wonder Woman of Earth 2? Or did it just not happen? It's best ignored.)
Next, feature just one villain. It's bad enough when movies like Batman Returns or Spider-Man 3 have the villain smorgasbord. But with seven heroes, there just isn't time for us to get to know more than one villain in a meaningful way. We want to know what makes our bad guy tick: his hopes, his dreams, his Barry Manilow collection. (Or hers.)
Give the JLA a mission statement. There has to be a compelling reason for the seven most powerful heroes on Earth to come together, and it's not to get a cat out of a tree. Don't waste our time with Lex Luthor or the Joker or Max Lord, or any problem that Superman could solve in five minutes on his own. This is a bigger challenge with JLA than with the Avengers, because no Avenger is remotely as powerful as Superman. (Sorry, Marvel fans.)
Don't do the "investigating separate cases that turn out to be related" thing. It's a tired device, and it strains our credulity a bit that everything our heroes are working on turns turns out to be parts of the same problem.
So that's a lot of rules. But how would I plot a JLA movie? Sadly, because I am a huge dork, I have given this a lot of thought. Here are my thoughts:
I would try to find a way to bring the heroes together organically, and not bring together all seven at once. First of all, I'd bring the scifi heroes together (everyone except for Batman, Wonder Woman and Aquaman).
Say there's some kind of emergency in space. And Superman, Martian Manhunter and Green Lantern all investigate. Green Lantern brings Flash along because they're best friends, and Flash can react faster than anybody. (I would make the friendship between Flash and Green Lantern a cornerstone of a JLA movie, and then let us see the other heroes through their eyes.)
These four heroes have to team up to stop some kind of alien threat to Earth. (Maybe Starro, or Brainiac. Or possibly (gasp) a totally new villain who's not from the comics.) At first, they seem to be succeeding, but then it turns out the alien attack was a ruse to distract the heroes, while the aliens planted some kind of advance guard on Earth. Maybe the aliens deposit spores somewhere. Or cybernetic probes, or some of Starro's mini-mind-controlling starfish.
To track down the alien items, our heroes need the help of the world's greatest detective, the mysterious Batman. He refuses to help at first, until some of the alien technology starts having a weird effect on humans in Gotham city. (Maybe there are hideous spores that start bursting out of people. Or people have silly starfishes on their heads. Everybody's afraid of starfish-head disease.)
Our heroes also try to recruit the world's greatest warrior, Wonder Woman, to fight the coming alien invasion. Meanwhile, one of the fragments has fallen into the ocean, and Green Lantern asks Aquaman to help look for it.
And then in the final act, all seven heroes need to work together to prevent a full-scale alien invasion. Somewhere along the way, they start acting more like a team, and the three characters who didn't go into space in the beginning learn to trust the other four. They're only able to save the Earth by combining all their abilities, and even then it's a near thing. They realize they'll have to develop their teamwork, or they might not managed to save the world the next time.
Okay, that's my Justice League pitch. What do you think?