I recently got interested in making computer games, and spent a couple of weekends doing unity tutorials and messing around. I have a tendency with any new subject I get interested in to immediately want to learn the 'state of the art', the best knowledge currently out there.
This resulted in me spending an afternoon busily compiling a list of game design books from Google, Reddit and Amazon, and sorting them based on content and review to figure which order to read them in.
'Theory of Fun' by Raph Koster was described as a great read by a lot of reviewers, and fairly short, so I quickly decided to read it first. Unfortunately, I went in expecting to hear concrete advice from his own time in the industry, and what I got was an essay on what makes games fun. You can kind of expect this from the title of the book, so it's mostly my own fault, but just a warning to anyone else there looking for concrete advice, this isn't it.
So the book - it spends the first half of the book talking about his theory of fun, and the second half of the book talking about why games are art. I'd already accepted the premise of games being art long ago, so I didn't get much out of the second half.
The first half raises some interesting points about various aspects of psychology and how they're reflected in game systems. This is fascinating stuff, however most of the psychology is familiar to anyone who took a course in psych at high school or university. I've studied psych at uni myself, so this wasn't anything new either.
Do I recommend this book?
I definitely recommend this book if you don't have a background in psychology, and if you're interested in what makes players enjoy games. If you're like me and you want concrete advice on building a game, then you can probably get away with just knowing that the main takeaway from this book is: "Fun is figuring out complex systems and solving problems in a risk free environment".