What’s the goal in an “infinite game” like D&D – how do you win?
One way to look at this question is: if you’re having fun, immersed in a robust world and experiencing an exciting story, then you’re “winning.” But for those concerned with more quantifiable metrics of success, it usually means leveling-up. Which means earning Experience Points (XP).
In the old AD&D rule system (circa the late ’70s), you received Experience Points (XP) for killing monsters and acquiring loot – simple as that. In our campaign characters do get credit for doing these sorts of heroic things, but to a greater degree XP is awarded based on the narrative content of play.
That is to say, it’s important to run a character in a way that is consistent with the character’s definition: alignment, personality, personal goals, etc.: in the words of Mr. Glass (in the film Unbreakable),
“… doing what you’re supposed to be doing.”
In this way, gaining XP could be seen as somewhat analogous to the process of individuation in Jungian psychology or Maslow’s idea of self-actualization: it’s about acting in such a way as to become what you’re meant to be, to fulfill your character’s “destiny” …
The intent of this approach (which, admittedly, relies a great deal on the subjectivity of the DM) is to further the idea of “winning the game” in both quantitative (leveling-up) and qualitative (experiencing a compelling story) terms.