By the time I reached the final scenes of the movie, I was starting to get twitchy from exhaustion. I’d now been up for over twenty-four hours straight, jacked in the entire time. The last action I had to perform was instructing the WOPR supercomputer to "play itself" at tic-tac-toe. Since every game the WOPR played ended in a tie, this had the improbable effect of teaching the artificially intelligent computer that global thermonuclear war, too, was a game in which "the only winning move is not to play." This prevented the WOPR from launching all of the United States’ ICBMs at the Soviet Union.