A game is more than a sport, pastime, and amusement. It is also

a model of the real world. For the ancient Greeks a game pro-

vided a liberal education in religion and love. For the players and

spectators of the Middle Ages in Europe it taught the main ele-

ments of the new civilization, chivalry and learning, which we

now call fair play and skill. The word "game" itself is a deeply

rooted native of the English language. Long before print, the

writers of manuscripts used it not only for the delight of pastimes,

but also for amorous play and pleasant stories; and ff one was

dealt with severely in the real world, it was a hard game. A game

w~s also, on another level, a way of acting by policy or plan,

which gave a hint of a later development. In the nineteenth cen-

tury, according to legend, a Parisian bookmaker, frustrated in his

efforts to make a profitable odds line on the horse races, appealed

to a mathematician who thereupon conjured up the theory of

probability, which became the rationale for predicting the aver-

age or expected outcome of the dice and roulette whee/s of the

casinos, the spimaing particles of modern atomic science, and

common decisions in face of risk.

Thus the idea of real-life games-the subject of this book-ls

as old as the hills. What s new in our time is game theory. Its

insights into games of strategy illuminate still another aspect of

the real world: the free human interactions that are beyond prob-

ability. The main unsettled question in economic thought-to

which game theory is directed-is how to understand the indefi-

nite outcome of interactions among people who can, within limits,

make free choices. Freedom of choice defies prediction in the

usual sense. The standard doctrine of free enterprise, for example,