San Diego, California - Comic-Con returns in full force to San Diego this week, where a hugely anticipated Marvel superhero film event is among the draws for tens of thousands of hyped-up fans dressed as fantasy heroes and sci-fi villains.

One of the world's largest pop culture events, Comic-Con began five decades ago as a humble comic book-themed gathering in a hotel basement, but today draws vast crowds and A-list stars promoting new movies and television shows.

Last year's edition was dampened by Hollywood strikes – which prevented actors from attending and quelled fan interest – but Comic-Con is expected to draw 130,000 attendees back to the southern Californian city this time around.

The hottest ticket is the Saturday night Marvel movies presentation, at which parent company Disney is expected to unveil plans to reboot its mega-grossing superhero film franchise, after years of high-profile missteps.

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The Marvel movies dominated Hollywood and global box offices for years, with 2019's Avengers: Endgame briefly becoming the highest-grossing film of all time at more than $2.79 billion.

But the past few years have brought more flops than hits, as fans complained about over-complicated plotlines and mourned the departure of favorite characters like Robert Downey Jr's Iron Man.

The franchise has been rocked by domestic violence revelations about actor Jonathan Majors, who had been set to become the major new supervillain across multiple films.

Majors, who was convicted of assaulting and harassing his then-girlfriend, has been dropped by Marvel, but there is no word on who – or what – will replace him.

Saturday's presentation is expected to reveal how Disney will move forward without him and has been billed as a potential "make or break" moment by some observers.

It will take place inside the 6,000-capacity Hall H, where many camp out in line for days to gain access.

"If the company wants to lure in anyone besides the dwindling ranks of... diehards, it needs to bring the answer to these questions to Hall H," wrote Susana Polo for Polygon.

Also on the Comic-Con lineup from Disney is a look at Alien: Romulus, the latest in the long-running sci-fi saga, and a "celebration" event for this weekend's major superhero release, Deadpool & Wolverine.

Rival studio Warner, which runs the DC superhero movies, is keeping a lower profile, but will offer a glimpse at its Batman spinoff TV series The Penguin, starring Colin Farrell.

Elsewhere, Those About To Die, a bloody romp through Ancient Rome and its macabre world of chariot races and gladiator fights, starring Anthony Hopkins, will host multiple fan events.

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Amazon's Prime Video will lift the lid on the second season of its Lord of the Rings television series, which aims to improve on the mixed reviews for its hugely expensive debut season two years ago.

And following the success of recent video game adaptations for the small screen such as Fallout and The Last of Us, Amazon will take viewers into the underworld of Japanese crime lords with Yakuza: Like a Dragon, based on the hit games from Sega.

But for many, Comic-Con is primarily a place to dress up as Disney characters or fearsome samurai warriors and meet with like-minded fans to buy and trade comic books.

Comic-Con runs from Thursday until Sunday.