I was just playing chess against my computer, and suddenly I realized that computer chess has no rules. In computer chess there are things that happen and things that don't happen; there are "laws of nature" (although "nature" is here a computer running a certain software), but there are no rules in the sense of "things regarded as customary or normal", as my dictionary says, or in the sense of "a convention set forth or accepted by a group of people". This way, computer chess is very different from over the board chess. Do you agree?