"My friend Eric Zimmerman likes to say, 'Games are structures of desire.' I don’t like the phrase, for two reasons. Firstly, it’s pretty obscure; it needs to be explained before you ‘get’ it. Second, it makes games sound like a whorehouse.
"But Eric is on to something here. By 'desire,' he means that games have
goals, and players mutually agree to behave as if the goal is important to them
when they play – the game creates a desire to achieve the game’s own goals.
By structure, he means that the interaction of the game’s rules, components,
software, etc. create a structure within which people play."