I'm not sure I've ever heard of a bolder conceit for a game—or a more doomed one—than Star Wars Galaxies' original pitch that almost no one would get to be a Jedi. In the Star Wars films and expanded universe, only a tiny portion of the trillions of people across the galaxy were Force-sensitive, so the developers locked Jedi abilities behind an opaque set of conditions that made becoming a Jedi difficult and mysterious. Eventually the developers were pushed to make becoming a Jedi easier, and in what one of the developers called "the most infamous patch in videogame history," they turned Jedi into a basic class option. The game was never the same after.
Before that, though, Star Wars Galaxies was a true sandbox MMO, an online space that players created their own identities and goals within. Impossibly ambitious, sure, doomed to turn off a lot of players, sure, but bold in a way that made the players who loved it really love it. I was thinking about that commitment to Jedi scarcity when I talked to the creative director of upcoming survival MMO Dune: Awakening after watching the new film, which is all about Paul Atreides becoming Dune's equivalent of Luke Skywalker, to grossly oversimplify things.
