Essef - Is it a game or is it real? Book of the film that inspired thousands of teenage hackers. David Lightman is an average teenager. Well, almost. For David has one obsession in life - computers. And he is good, very good. He can tap other computers to feed or extract information. (He even persuades his school computer to improve his grades). So when he enters an unidentified computer system he unwittingly becomes a player in the biggest games programme in the world - the computer belongs to the US Defence Department; the game is that of Global Thermonuclear War; the stakes are the deadliest of all.