This book is an appropriate gift for a teenager with a taste for mathematics. Highly accessible, requiring some algebra, but not much more, the book introduces the deceptively simple mathematical subject of game theory. First of all, it indicates what is =meant= by a game -- something more akin to rock, paper, scissors, than monopoly or chess. Game theory (in a way like chaos theory) is seriously mis-named; the games played tend to be ones that are simple models of economic choice or political strategizing. This is why research in game theory has led to the Nobel Prize in Economics for more than one person.
In any case, I used this book as a resource in a discrete math class for teenaged students who were extremely interested in math. It was intended for non-math majors in college, but I think it would work very well as enrichment in the high school classroom (or even middle school -- one can use it in developing an application for algebra). After learning the rudiments of game theory, I thought to apply the concept to =The Weakest Link=, and found that, as a game, it is far more complicated than what you'll find in this book.
Still, this is just a starting point. There are plenty of avenues to explore beyond what is covered in here, but one can get bogged down with all the different types of situations that have been treated in game theory.