“The lesson for designers is simple: a game is destined to become boring, automated, cheated, and exploited. Your sole responsibility is to know what the game is about and to ensure that the game teaches that thing. That one thing, the theme, the core, the heart of the game, might require many systems or it might require few. But no system should be in the game that does not contribute towards that lesson. It is the cynosure of all the systems; it is the moral of the story; it is the point. In the end, that is both the glory of learning and its fundamental problem: once you learn something, it’s over. You don’t get to learn it again.”