Adversary Search

What's an adversary? An adversary is an opponent. For us, an opponent to play against in a two-player game.

One of the first things scientists tried to figure out how to do with computers was to get them to "think" and not just "compute". One place they started was with the game of chess. Chess is nice for this because it is easy to play, but hard to play well. Things that make it easy to play include:

  • Just two players

  • The players take turns

  • The game always ends

  • If one player wins, the other loses

  • There's no luck to worry about

  • You and your opponent know the same things about the game

  • There aren't too many choices of move each turn

It turns out that many games are of this form. In fact, real life is sometimes like this too. So any way of building a computer player for a "chess-like" game can be used for lots of things.