SAN DIEGO -- All is not well for Superman, audiences at Comic-Con found out on Saturday during a jam-packed and revealing Warner Bros. presentation in Hall H. The studio also debuted a first look at the comic-book movie "Suicide Squad" at the annual convention.

But it was "Batman v Superman: Dawn of Justice" that was the main event that fans had camped out for days to see. Stars Ben Affleck, Henry Cavill, Gal Gadot and Jesse Eisenberg were on hand to talk about the superhero showdown, too -- a step up from last year's Comic-Con when none of the stars was allowed to talk.

In the first full trailer for the film, out on March 25, 2016, we see a society that has turned against the godlike Superman (Cavill) following a massive disaster. While Holly Hunter's steadfast Senator schemes with Eisenberg's Lex Luthor to protect the public from the dangerous Superman, Affleck's Batman decides to take matters into his own hands.

"The idea of Batman fighting Superman is a thing that happens all the time in comic books," said Zack Snyder, who also directed "Man of Steel." He likes to pay homage to Frank Miller's "The Dark Knight" but wanted to make clear that this story is not that story.

Oscar-winning screenwriter Chris Terrio ("Argo") wrote the script.

Snyder said the story will also launch toward bigger conflicts with other superheroes.

"Who knows?" he said coyly. "I mean, I do know."

While audiences have met Cavill's Superman before, this is their first real introduction to Affleck's Batman.

"I think if I thought too hard about the actors who played this part before, I couldn't have taken the job," said Affleck. But Snyder explained to him that this Batman would be different. He told Affleck that Bruce Wayne here is at "the end of his rope, he's older, he's a burnout."

As the villain Lex Luthor, Eisenberg said that there's "always a campy element to the character."

But unlike in previous versions, this Lex Luthor has an "emotional groundedness." He also has hair.

Gadot, who plays Wonder Woman in this film and in an upcoming stand alone, said her character has the "strength of a superhero" but is "very sophisticated, loving and has a lot of emotional intelligence."

Warner Bros. also showed the first footage from "Suicide Squad," another DC Comic about a group of imprisoned supervillains recruited by a government organization to perform black ops for their freedom.

The film, directed by David Ayer, stars Will Smith as Deadshot, Margot Robbie as Harley Quinn, and Jared Leto as The Joker.

The first trailer shows the origins of the gritty, punk rock group of villains turned heroes.

"So that's it, we're the patsies. We're some kind of suicide squad," Smith's Deadshot says in the trailer. "So let's save the world."

Leto's sniveling Joker, who sounds strikingly similar to Heath Ledger's version, closed the trailer with an ominous threat.

"No, I'm not gonna kill you. I'm just gonna hurt you, really, really bad," he says.

Ayer, who is in the middle of shooting the movie in Toronto, made it a priority to fly to the convention with his cast.

"It's time for bad versus evil," he said. "It's time for a movie about bad guys."

Ayer brought out Smith, Robbie, Viola Davis and others to say hello and quickly exit the stage. Smith said they'll be back next year for the film, which comes out on August 5, 2016.

Warner Bros. also brought out some of the cast of the Peter Pan origin story "Pan" and the 60s espionage film adaptation "The Man from U.N.C.L.E."

Director Joe Wright, and stars Hugh Jackman (Blackbeard), Garrett Hedlund (Hook before the Hook), and newcomer Levi Miller (Peter) talked about creating the dark fantasy world of "Pan," which comes out on Oct. 9.

Wright told Hedlund that he wanted to make the film as dark as possible. It's intended to teach children that, "no matter how dark the fear they can always overcome the nightmare," said Hedlund.

Jackman also marveled over the massive practical sets Wright built to represent Neverland. He estimated that it was about three times as big as the 6,500-seat Hall H. Miller compared it to a theme park.

"I love building physical things. I love building playgrounds for us all to play in," said Wright.

Armie Hammer and Cavill also came out with co-stars Alicia Vikander and Elizabeth Debicki to preview the stylish spy film, "The Man from U.N.C.L.E," which comes out on Aug. 14.

It might not be 'Batman v Superman' but Cavill, as CIA agent Napoleon Solo, does get to fight with Hammer, as KGB agent Illya Kuryakin, even if it's slightly less sophisticated than his superhero character might be comfortable with.