In my opinion tragedy requires a catharsis to be satisfying, and to pull off a tragedy well all the players generally have to feel as if 'it was worth it.' A story doesn't have to have a happy ending - it has to have a satisfying ending. A recent, post-modern attempt at classic tragedy as a modern film was obviously Gladiator. There was nothing happy about that movie and yet I'd argue that the ending was incredibly satisfying and that the film crew did a great job in trying to capture that aspect of catharsis that is so important in a good tragedy. If you don't have a catharsis, if you don't feel it was worth it, then you'll end up feeling betrayed and annoyed with stories that lead you to your doom. And that's a huge weight to carry around as a GM, as a pocket-GM for your own characters, etc. Just as an acting troupe gets a taste of the script before they agree to play it, whenever I start up a tragedy, I like to give the players an understanding of the way things will go. This is what I see as the first step necessary to building the kind of savage trust level needed to go through a brutal storyline. Can the players trust you to make it worth it for them? Whew, what a question!
