It seems a cardinal rule that anyone who performs in a comic book movie is subsequently banned from taking any other roles in comic book movies, in case the fans respond badly to the fact that that guy playing Fantastic Four is also Captain America and thus the magical hint that the two superheroes might exist in the same world is utterly destroyed. And for the most part, the myth of mostly singular appearances has endured: only Chris Evans really stands out as a key figure to jump from one established franchise (which quickly became a comically sinking ship) to another, and even that was met with concerns at the time of casting. Or at least a few quizzically raised eyebrows. But for all the suggestions that it simply isn't right to play a part in more than one comic book movie, a surprising number of actors have done precisely that - happily flouting the established rule to take roles that complicate the shared universe theory, or even worse, merrily hopping from DC to Marvel without a second glance at the political connotations of what they have done. In the animation world, the tendency is far more obvious, with the likes of Ron Perlman and Mark Hamill playing multiple (usually villainous) roles, but that is somewhat to be expected, and there doesn't seem to be the same assumed forbidden status of multi-performing in that medium. So who makes up this band of actors who have starred in more than one comic book movie? Some you will undoubtedly be aware of - like Ben Affleck, who hasn't yet made it to two, but will with Batman Vs Superman - but others are slightly more obscure, including Tim Blake Nelson who is set to make his a double score with the upcoming Fantastic Four...
Honourable Mention
Patrick Leahy Though he's not an actor in the strictest sense of the word, United States Senator Patrick Leahy appeared in two separate Batman universes, as well as being a guest voice on Batman: The Animated Series. The Senator is a self-confessed fan of Batman and played an extra in 1997's Batman & Robin, before upgrading to a brief speaking part in The Dark Knight, as the party-goer at Bruce's fundraiser who says "We are not intimidated by thugs."