Introduction
Standard introduction - but one important note: "while the goal of this book is primarily to teach you how to be a better videogame designer, many of the principles we will explore will have little to do with videogames specifically."
Game design is defined as "the act of deciding what a game should be." It's not about programming techniques. I none sense, it's the "story" of the game, but it also has to do with designing the various interactions in the game and the mathematical models behind them.
In the professional space, "game designer" is a role on the development team - basically, the architect for what the artists will draw and the coders will program.
Presently, there is no unified body of theory, no existing formula for making a game, only a number of perspectives (the author calls them "lenses") one can take to help arrive at the product.
Videogames are just a natural extension of traditional games into the new medium - they're essentially no different than card games, dice games, playground games, etc., though the computer medium is capable of crunching a lot of numbers, very fast, to provide a game of complexity without burdening the user. That's not to say a "good" game is complex. Some of the most commercially successful video games have been very simple mathematically, but yet compelling.
But more to the point, the same principles apply, and it's those principles that this book intends to address.
The author also encourages designers to reach beyond the "tried and true" methods. Nothing "new" is invented by doing what is known, only cookie-cutter copies of existing games with slight variations.
He refers to a "complex web" of components - creativity, psychology, technology, and business - that drive the industry. They are interconnected and interdependent.
The author also indicates that book-learning alone won't do it. This book is a starting point, the topics within it are part of the overall knowledge. Ultimately, the best learning comes from experience. Go do it.