SAN DIEGO >> Every summer, Hollywood comes to Comic-Con International, the carnivallike pop culture convention here, to promote its coming mass-market movies. And the offerings usually have a numbing similarity.

Macho directors — almost always white men — stride onto a stage and introduce footage of sparring superheroes, and then trot out cast members (again, mostly white) for some schmaltzy chitchat about loving their characters. Rinse and repeat.

There was plenty of that kind of thing this year, too. But for the first time, studio presentations paid more than lip service to diversity.

Marvel Studios started its Saturday session inside the San Diego Convention Center’s cavernous Hall H, which seats roughly 7,000 people, by bringing out Ryan Coogler, the director of the big-budget “Black Panther,” and his four black leads: Chadwick Boseman, Lupita Nyong’o, Michael B. Jordan and Danai Gurira. “This is my first time here,” a beaming Boseman told the crowd. “It feels amazing.”

“You’re awesome!” a woman shouted from the audience. “Black Panther,” centered on a superhero from a fictional African nation, is scheduled for release in 2018.

From there, Marvel moved on to “Thor: Ragnarok,” directed by the New Zealand filmmaker Taika Waititi and featuring Idris Elba and Tessa Thompson (“Creed,” “Dear White People”) in major roles. The Disney-owned superhero factory, which plans to unleash “Ragnarok” in November 2017, ended by announcing that the Oscar-winning actress Brie Larson would play the lead in “Captain Marvel,” which is planned for 2019 and will become the first Marvel movie anchored by a woman.

The crowd (and, subsequently, Twitter) had an ecstatic meltdown.

Earlier on Saturday, during a lavish 2 1/2-hour presentation, Warner Bros. could also be seen working hard to bring diversity to its event movies. A centerpiece of the Warner session was “Wonder Woman,” directed by Patty Jenkins and starring Gal Gadot. A new trailer for that film, scheduled to arrive in theaters next summer, found Gadot charging into battle on horseback, using her shield to fend off military attacks and ensnaring bad guys with her magic lasso.

(Alas, Jenkins confirmed that the character would not be seen piloting her invisible jet. “It takes place in such an early period, I don’t think it would be the jet we want,” she said. Conan O’Brien, who served as moderator for Warner’s marathon session, got laughs by adding, “Also, if it was there, you wouldn’t know it.”)

Warner also pulled out all the stops for “Suicide Squad,” which arrives on Aug. 5 and is expected to be a monster hit; services that track audience interest are predicting opening-weekend ticket sales exceeding $100 million. The film’s director, David Ayer, marched onto the Comic-Con stage wearing a trucker hat reading “Make Mexico Great Again,” bringing along cast members like Will Smith, Margot Robbie, Viola Davis, Adewale Akinnuoye-Agbaje, Jared Leto, Jay Hernandez and Karen Fukuhara.

It became another moment of female empowerment. The breakout “Suicide Squad” character — at least judging by the sheer number of Comic-Con attendees who dressed like her (Halloween costume alert!) — was not Smith’s Deadshot or Leto’s Joker but Robbie’s Harley Quinn, the Joker’s sexy, utterly deranged girlfriend.

“I don’t know anyone else in the business right now who would have both the stamina and the will and the talent to pull off what Margot pulled off,” Ayer said, speaking specifically about her stunts. Robbie seized the compliment, adding, “Whatever anyone did in this film, I did in a pair of heels.”

Comic-Con, which ran from Wednesday to Sunday, started in the 1970s as an almost entirely male gathering of comic book enthusiasts. It has grown into a sprawling event for fans of superheroes, horror movies, animation and television shows of all kinds, attracting roughly 140,000 people to downtown San Diego every July. The nonprofit organization behind the event does not release demographic information about attendees, except to say that crowds are now roughly 50 percent female.

Aside from the clear push toward inclusion from entertainment companies — the Fox broadcast network came to promote its “Rocky Horror Picture Show” remake, which stars the transgender actress Laverne Cox in the showcase role — Comic-Con was notable this time around for what it did not have: visibly heightened security.

The convention, which has never had a major safety incident, has long insisted that covert security efforts are enough, especially because organizers say the event tends to attract a good-natured crowd. Because of the increasing frequency of mass shootings and the recent truck attack in the South of France, some longtime attendees said they expected the event would follow theme parks, baseball stadiums and other public venues in walking people through metal detectors and checking every bag. But such measures were not taken.

Comic-Con officials declined to comment on security planning, aside from noting that the event works closely with the San Diego Police Department.

Some Hollywood executives spoke privately about their unease with the lack of visible security, but most fans seemed to be more concerned with racing to panels concerning their favorite movies and television shows, shopping for collectibles on the trade-show floor and gawking at pass holders who turned up in costume — including the occasional one that was impossible to unsee.

One fulsome man, for instance, walked around nude except for a white diaper and a “Ghostbusters”-style Proton Pack, a comment on the fanboys who acted like babies over Sony Pictures’ recent remake of that comedy with women in the lead roles.