What role does cosplay play at Comic-Con San Diego, and how do people participate?

Cosplay (costume play) is a fundamental and vibrant part of Comic-Con San Diego. Attendees dress up as characters from comics, movies, TV shows, video games, and other pop culture media. It's a huge aspect of the convention's atmosphere, with many participants spending months preparing elaborate costumes. People participate by simply walking around in costume, posing for photos, or entering official contests like the Masquerade, which is a major highlight featuring performances and craftsmanship judging.