Does making a Tic Tac Toe game require artificial intelligence?

Answer 1

Yes. Anything that requires the machine to "think" as a human thinks requires Artificial Intelligence (AI). The amount varies from application to application. Tic Tac Toe (or Noughts and Crosses) doesn't require complex AI, because once you exclude rotations and mirrors, there are only 3 possible opening moves (corner, middle or side) and each has only 8 possible counter moves, there being only 8 positions remaining to choose from. Thus every possible game can be mapped in a relatively small decision tree.

Keep in mind that point of Noughts and Crosses is not to win, but simply to avoid losing. With two competent players, every game must end in a draw because there is no way to win unless your opponent makes a critical mistake. However, because the strategy is so simple to model, we can mimic the way a human learns how to play the game, and thus give the computer the intelligence to work out how not to lose.

That is, the computer starts out playing the game with only the knowledge of where to place its mark according to the rules of the game. As it does so it gradually builds up the decision tree. When a position that it has already seen appears again, it simply tries the next possible counter move. Eventually, every possible counter move will have been mapped and the outcomes of each game marked as lose or draw (winning strategies will only be recorded if the human makes a mistake during the learning process). From this it will determine that the best opening move is the centre position and will ignore all routes that lead to a loss. The computer has effectively learned, via artificial intelligence, how to avoid losing at Noughts and Crosses.