The other thing that I was thinking about related to yesterday's post and megadungeons, which I intended to write about but ended up writing my expat gamer blues post, was about Forge style indie RPGs and a weird similarity they share with a megadungeon campaign, the way I'd run it.
For those not in the know, the Forge was the home of GNS theory. Now they've moved on to something else, and while interesting to read, I could really care less about most of the things they talk about there.
But most of the games born out of GNS were a) designed to deliver one, and only one, flavor of gaming--Gamist, Narrativist, or Simulationist. The idea being that a 'well designed' game only caters to one interest. And the vast majority of Forge games catered to narrativist style.
In these games, there is typically a game setting and style tied to the rule-set. If you're playing Dogs in the Vinyard, your character is a Mormon paladin gunslinger in the evil Old West. End of story. You can give your MPG any sort of personality you like, but the game only works if the players are MPGs running around getting forced into morals challenging situations about how to clean up evil towns. Players who don't want to be a MPG need not apply.
And a Megadungeon campaign really isn't so different from one of these, at least to start. Assuming you're using D&D, AD&D or a retro-clone, no matter what your class/race/alignment/personality, your character is a dungeon delver. That's what you do. The rules assume it, and players who don't want to be dungeon delvers need not apply.
The only real difference is that in DitV, that's the whole of the game. Whereas in D&D et al. you can get out of the dungeon, explore the wilderness, become rulers, etc. There's expansion. But early on, and potentially for the whole campaign if it's interesting enough, dungeon delving is what it's all about.
Even though they have completely different intents and styles, there is that commonality of implied 'character buy in' in these games. You can't be just anything you want and expect it to work. You have to give up some of that precious control over who your character is to allow the game to work.