There’s a new and very special sort of hybrid game doing the rounds, a marriage between the large scale politicking of live-action roleplaying (LARPs) and the focused, often crunchy mechanics of an economic game. It’s played with dozens, even hundreds of players, it takes a whole day, and it has a slightly clumsy sobriquet that perfectly encapsulates its grand ambition: the “megagame.”

Megagames have no strict definition, but here’s an outline of the (pretty typical) first one that I tried, two years ago now. Strange alien forces mass near the earth, alarming the world’s governments. Multiple teams of three to six players represent various nations, and teams take on roles like diplomats or military leaders. Each plays its own straightforward game of economics to balance the country’s budget, fund the military, and direct scientific research.