From Pokemon onesies to Disney frocks, comic and film fans from across the world will don costumes this week (July 21-24) and descend on California to spend four days geeking out.
Every July, San Diego transforms into Nerd Town USA, as tens of thousands of monsters, aliens, Manga characters and caped crusaders throng the streets for Comic-Con International.
Since its humble beginnings in 1970 as a convention of a few dozen geeks who swapped superhero magazines, it has exploded into America's largest and most spectacular pop culture event.
The convention is expected to welcome 130,000 cosplayers, movie executives, sci-fi fans and bloggers to feast on all manner of panels, screenings and other fan events and attractions.
The center of the Comic-Con galaxy is the 6,500-seat Hall H, where big name stars drop by to promote their films and TV shows, and fans have been known to wait in line for more than 10 hours to get in.
For Americans, the price of attending the Comic-Con is estimated at around $1,850, including entry badges, air fare to San Diego, hotels, costumes, and food -- and costs rise significantly for those flying in from abroad.
The evolution of smartphone technology and the emergence of social media have raised the specter of piracy this year, with one big studio reportedly having pulled out over leaks of footage onto the internet.
Last year, a Warner Brothers reel for "Suicide Squad" intended only for the convention attendees was quickly bootlegged and put online, forcing the studio to hastily release a brushed-up version.
Trailers for "Deadpool" and "X-men: Apocalypse" also leaked onto the internet during last year's convention.
The Los Angeles Times and entertainment website, The Wrap, reported that "Deadpool" distributor 20th Century Fox decided to sit out Comic-Con this year over piracy concerns, although the studio has declined to confirm this was the reason.
Shawn Robbins, a senior analyst at movie data website Boxoffice.com, raised the possibility that other studios might start pulling back from making exclusive material available at fan conventions.
"The exclusivity of it has already disappeared in recent years, not just due to pirated leaks but even because of official trailer releases that have been timed during or close to various conventions like Comic-Con and CinemaCon," he told AFP.
"While these gatherings are about much more than just a few minutes of footage from movies, that has nonetheless become a big selling point."
Described by Rolling Stone magazine as the "Super Bowl of people who don't like watching the Super Bowl," Comic-Con boasts a cornucopia of stars hawking their latest movies and TV shows.
On Wednesday night, Paramount staged a glitzy open-air US premiere of Star Trek Beyond, attended by the cast and crew and complete with a live performance of Michael Giacchino's score by the San Diego Symphony.
Warner Bros. takes over Hall H for two hours on Saturday, with Conan O'Brien as host, to pull back the curtain on its highly anticipated slate of both DC Comics movies and non-superhero offerings.
Stars expected to attend include Wonder Woman leads Gal Gadot and Chris Pine, while Will Smith, Jared Leto, Margot Robbie, Cara Delevingne, and director David Ayer are due to show up for Suicide Squad.
Next spring's Kong: Skull Island will be presented by Tom Hiddleston, Brie Larson and John Goodman and there will be a first-look at Harry Potter spin-off Fantastic Beasts and Where to Find Them with Eddie Redmayne and Colin Farrell.
Another of the most talked-about offerings of the convention will be Marvel's Hall H presentation later on the same day, which should include an appearance by Chris Pratt for Guardians of the Galaxy 2.
Ringmaster Kevin Feige may also treat audiences to a peek at Dr Strange, Spider-Man: Homecoming and Thor: Ragnarok.
On the television front, AMC has perhaps the pick of the convention with panels devoted to The Walking Dead, the most successful show in cable television history, and its spin-off, Fear the Walking Dead.
Sue Kroll, Warner's president of worldwide marketing and distribution, sees Comic-Con, which is expected to raise $140 million for the local economy this year, as one of the company's favorite events.
"It's always exciting for us to give these fans a taste of what we're bringing to theaters in such a direct way, connecting them with the talented actors and filmmakers who work so hard to make everyone's movie-going experience a memorable one," she said in a statement.