Ralph Koster wrote a guest post for today’s Penny Arcade. It’s way interesting:

Games are made out of smaller games – turtles all the way down, until you hit the game that is so trivial and stupid it isn’t deserving of the name. In an MMO, we nest games pretty deep, because some games are short-term and some are long-term. In something like WoW, the smallest games are things like “hit Heal on time.” Then you get ‘kill the foozle,” and above that “kill a hell of a lot of foozles” and above that “make yourself stronger by picking the right gear” and in some cases “make your guild stronger” and so on.