In art (in the broad sense), the term catharsis is used to refer to the phenomenon of someone having a strong emotional reaction through a character. Usually this is a very profound sensation and is only generated by the works of outstanding artists.

However, though many of the strongest manifestations of catharsis occur through art, the phenomenon is not confined solely to it. It also happens to some people who watch sports -- and, I've noticed, frequently occurs in all sorts of role-playing games, from the simplest Monty Haul hack-and-slash munchkinfest to the deepest dramatic games that could arguably be called art in themselves.

Of course, some people, most notably the "Religious Right", tend to mistake catharsis for confusing fantasy with reality or worse, especially when it happens through RPGs. Heaven forbid that their children experience something meaningful that doesn't have to do with their parents' narrow view of what God is...