Ian Bogost has an interesting essay up on Gamasutra, this one on the performative aspects of video games. The beloved word of anthropologists and linguists the world over, the concept of something being 'performative' is when something has the ability to do something itself when it is thrown out in the big bad world. So, what does this have to do with games?:
Video games often face a challenge: what does playing a game do to people in the world? In the case of entertainment games, such a question asks about the effects of violence on players, or about how players find and evaluate meaning in games.
In training, advertising, and learning games, the question asks how players take knowledge they learned in a game and apply it in their daily lives. The motivational (and compulsive) aspects of games suggest other ways gameplay can influence behavior. But such matters cover only part of the intersection between our game lives and our ordinary lives ....
Performativity in discourse produces action. Performativity in video games couple gameplay to real-world action. Performative gameplay describes mechanics that change the state of the world through play actions themselves, rather than by inspiring possible future actions through coersion or reflection.
The performative aspects of games go far beyond 'serious' games, and Bogost has a number of interesting examples — good reading for a lazy weekend.
Persuasive Games: Performative Play [Gamasutra]