Bernie Maddoff is in jail for the next 150 years. He misled investors with a Ponzi scheme, a scam in which you promise people a high return on investment, which you pay not with any real business, but with the money new investors give you. In real life, this is fraud, and if you are caught you will go to jail for it. In a game, for example if I offer you a dodgy deal for a street in Monopoly counting on the fact that you are bad with numbers, this is part of the game and I won't go to jail for it. It's just play money. But what of situations that are in between?