Warner Bros. secretly prepping Justice League movie in the wake of The Avengers

In the comic book world, whenever Marvel or DC Comics throw down the gauntlet — whether with a big event, crossover, or superhero death — the competing company invariably must do something to try to top their rival. The same thing seems to be true of the companies' movie studio counterparts in recent years, with the two comic publishers continuing their superhero battle on the big screen.

Marvel's recent success with the superhero ensemble "The Avengers" seems to have lit a fire under DC, who, according to Variety, are now quietly prepping their own superpowered assembly in the form of a big screen "Justice League" movie. Warner Bros. has enlisted the talents of "Gangster Squad" screenwriter Will Beall, who is also currently working on a reboot of "Lethal Weapon" for the studio.

The Justice League is basically the DC universe equivalent of Marvel's superteam the Avengers. In fact, Marvel created their group in direct response to the success of DC's Justice League comic books, which debuted three years earlier in 1960. Originally called the Justice League of America (JLA for short), DC's team is made up of all of their top tier heroes: Superman, Batman, Wonder Woman, Green Lantern, Aquaman, Flash, and the Martian Manhunter. Like the Avengers, the mix of heroes (and egos) creates some very interesting character dynamics and conflicts, but the JLA have always been a little more squeaky clean than their Marvel analogues.

Creating a Justice League movie is going to be an uphill battle for Warner Bros. and DC Comics. Marvel had set up "The Avengers" with five years' worth of films that were tied together in a contiguous universe. But of the superheroes featured in the Justice League, only two have been seen on the big screen in recent years, most notably Batman and Green Lantern. Under director Christopher Nolan, the recent Bat-movies have been very successful, while the big budget "Green Lantern" was not quite the success Warner Bros. had hoped for.

Superman — arguably DC's most recognizable hero — was last seen in 2006's "Superman Returns," a film that WB also did not consider a success, given its massive budget and comparatively modest box office gross. There is hope on the horizon for the big blue Boy Scout, though, as director Zack Snyder ("300," "Watchmen") is currently in post-production of "Man of Steel," the new Superman movie starring Henry Cavill as the titular strongman.

Anyone not living under a rock knows that comic book movies have become all the rage over the past decade, and both Marvel and DC have been at the forefront, with numerous box office successes on both sides of the comic universe divide (and a few flops to boot). "Batman Begins" and "The Dark Knight" were enormously successful for DC, while the "Iron Man" movies, "Thor," "Captain America" were all big hits for Marvel. That success will likely continue in 2012, with the big box office battle of the year looking like it's going to be between Marvel's "The Avengers" (which has already grossed over $1.3 billion worldwide) and DC's upcoming "The Dark Knight Rises" (a movie which poised to make an enormous haul).

Could a live-action "Justice League" film out-earn both those films? DC Comics and Warner Bros. really want to find out, but it could be a risky venture. Without the same amount of planning and setup that Marvel's "The Avengers" benefited from, introducing so many unestablished characters in one movie could be disastrous. It's also unlikely that Christian Bale would return to play Batman in the "Justice League" film, adding yet another untested element to the mix.

If "Man of Steel" and "Green Lantern 2" prove to be anywhere near the box office phenomena that Nolan's "Dark Knight" films have been -- and if DC uses them to set up the possibility of a contiguous universe of superheroes -- then and only then can Warner Bros. count on a "Justice League" movie being a sure bet.