 It seems obvious that the Petrograd game is worth more than the St. Petersburg game. However, it is not easy to explain why. Both games have infinite expected utility, so the expected utility principle gives the wrong answer. It is not true that the Petrograd game is worth more than the St. Petersburg game because its expected utility is higher; the two games have exactly the same expected utility. This shows that the expected utility principle is not universally applicable to all risky choices, which is an interesting observation in its own right.