Game Theory was first developed as a model for human decisionmaking back in the 1940's. Like the label suggests, it deals with analyzing human choices from a purely self-interested viewpoint. The idea is to map out all the possible foreseeable outcomes of a decisionpoint, and to assign corresponding weights to all of the contributing factors, in order to predict the outcome.
I guess an example might be something like a high school senior who has been accepted to five different colleges and is trying to decide which to go to. Each college has pros and cons (cost, reputation, proximity to home, etc) and the student has numerous different priorities (cost very important, reputation somewhat important, proximity to home not important...) which point at a given result.
That's a very simple example. The theory has been expanded to very complex scenarios, which consider hundreds of variables, and complex processes which involve multiple decisions. This is where the models get to be like a game... where one self-interested, objective decision begets an outcome which sets up for the next evolution of choices. The author worked on early computer game theory models in the 1970's (at the University of Rochester in NY), and even back then was successfully able to predict things like the outcome of elections, and what bargains the Soviet Union might agree to in nuclear arms talks, etc.
The triumphs and innovative applications of Game Theory are interesting to hear about, and the author avoids almost any mention of the underlying math... but that gets to be annoying. He plays his cards too close to the vest- is a bit too vague about the nuts and bolts of it all. About 100 pages in, I started to figure out that the book is basically a 250 page commercial for his consulting business. I don't say that in a bitter way; it's fine, and I learned a little bit about a complex subject that I'm not really required to know anything at all about, in my daily life. It was a pure curiosity read.
It's written at about a 6th grade level, so you can whip through it in no time. Just don't expect too much.