Tony Stark visiting Comic-Con
Iron Man ended, surprisingly, with Stark deciding not to keep the source material’s secret identity. Iron Man 2 ran with it, as has The Avengers less directly. So now the character is a huge star who you could see coming to Comic-Con just like that.
Most superheroes default to secret identities - the Fantastic Four being a rare exception - and most superhero games follow suit. Fantasy adventurers and spaceship captains tend to have public identities, but their fame doesn’t spread as widely or quickly as it could in the modern age of camera phones and press conferences, so most modern-day games follow superheroes in having the PCs and their enemies act in secret so that the world still largely looks like the one we live in. Some noteworthy exceptions include Demon: The Fallen and Scion, which starts with demigods and the like secret but the PCs can break that right away and have little reason not to, and Aberrant, where the secret broke ten years before the game begins and the celebrity culture around superhumans is a major focus.
And in a culture obsessed with celebrity and novelty, how would you feel about being yesterday’s news?
Fame isn’t necessarily welcome, of course. It’s obviously going to be problematic for PCs engaged in covert or criminal activities, or members of secretive groups. And more importantly, not all players want to deal with press conferences. If you don’t like public speaking, even in-character public speaking with only your gaming group as the real audience can still trip you up.
See also Sherlock series two for an example of fame proving more trouble than it’s worth.
A permanent change in the status quo, caused by the PCs or by other forces, could significantly affect how the game feels. Maybe no-one will mind, but as ever it’s best to check with the players before going with something like that. Having a reset button is often a good idea in case a campaign-changing idea doesn’t really work out. Look at how open the world of Doctor Who became, and then it went quiet again due to Cracks In Time.
A temporary change can make for an interesting change of pace with no such repercussions. Your team of superheroes could be zapped into a parallel universe where they’re world-famous, and deal with stardom as a novelty for an issue or two. Or your urban fantasy monster hunters are hit with a spell that removes the setting’s in-built Masquerade for the duration of an episode, so everybody they meet can work out what they’re doing, and they probably have to find a way to switch it on again.
Having action figures of your PCs is cool. Your PCs seeing action figures of themselves can be very strange indeed.