Abstract

During my childhood I was fascinated by videogames. One game that stands out in my memory is Pacman. It wasn’t the gameplay that interested me so much as the behavior of the ghosts. As you watch them roam around the maze, you get the feeling that they are intelligent. They seem to be making decisions about how best to catch Pacman. But how free are their decisions? One of the interesting things I noticed was that I could play exactly the same game over and over if I moved Pacman in precisely the same way each time. The ghosts always followed the same behavioral pattern and didn’t deviate from that pattern until I changed my pattern. Experimenting with Pacman in this way revealed to me something about the ghosts’ behavior. True, they make decisions, but their decisions are firmly and predictably determined by the way I move around the maze