Game Theory is not actually about games. It's about the way people (and animals, and even slime mould for that matter) live their lives. Playing what is known as the non-zero game is the driving force behind evolution in the current mindset of scientists, and is a fascinating topic.
Firstly, you need to understand what a zero sum game is. Put simply, it is a game where you have a winner (+1) and a loser (-1). When one person gains a point, somebody else loses one, and the net result is zero. Chess is a zero sum game; for one person to win the game, the other has to lose. The same applies to Football, Connect 4 and Pong.
The non-zero sum game makes for far more interesting dynamics. For stone age man living by a forest, one individual will catch one badger a day if he is lucky. If he doesn't catch a badger for a few days then he dies...unless he steals from somebody else, who in turn dies. However, if he teams up with 20 men, they will make a net, stretch it across the forest floor and catch 50 badgers every day. Every man benefits and there is a surplus to share. The game in play is how to divide the spoils, who controls the community of workers, and how to use the extra food to attract power and the ladies! Everybody wins, but some are bigger winners than others. In terms of evolution the zero game is static (always zero progress) whereas a well played non-zero game pushes mankind forwards at varying speeds.
In terms of creating a game, the scope of the non-zero game is almost limitless. This is the basis for many successful brands such as Civilization, FarmVille, Second Life and many more. By turning your mind from one winner / one loser, to one plus one equals three you might find yourself creating the next big thing and being part of game evolution.