Theory of Fun for Game Design
"Raph Koster was creative lead and lead designer on Ultima Online and Ultima Online: The Second Age, and the creative director on Star Wars Galaxies -- today, he's the Chief Creative Officer for Sony Entertainment (the division that does the video games). His new book is called Theory of Fun for Game Design, and I was lucky enough to read a review copy last month.
Raph's intention here is to write a Understanding Comics for computer games: an accessible, lay-oriented text that explains, finally, what this medium means. Why are grownups playing games? What makes a game fun? What do games do to the way twe perceive the world? What do games do to the way we change the world? " (http://www.boingboing.net/2004/10/13/theory-of-fun-unders.html)