In October 2011, the Greek economist Yanis Varoufakis received an unusual email. "I'm the president of a videogame company," it began. The message was from the head of Valve Software, the influential video game design firm behind such industry-defining titles as the sci-fi shooter Half-Life and the first-person puzzle adventure Portal. During the height of the Euro crisis in Greece, Varoufakis was often seen in the media explaining the meltdown and describing what might happen next in the currency-integrated Eurozone. Peter Suderman spoke to Varoufakis about how he's now applying the same insights to the interlinked virtual economies of Valve Software's games.