Simulation games can model complex real-world relationships andsystems in ways that are nearly impossible for static words and images. Consider, on any given day in a history class a teacher or text could declare something like, “Throughout the past, resources have been scarce and finite. This has meant that societies, historically, have had to make often difficult choices about how best to allocate resources. Societies had to make trade-offs between conflicting goals.” Reading or hearing this is a very different experience from dealing with the reality of such trade-offs in a computer simulation game like, say, Civilization. Each city in that game has a labor force that can exploit resources from one of the squares of the land surrounding the city and, in doing so, add to the economic, scientific, and productive efforts of the city. The more citizens a city has, generally speaking, the more productive the city is. There are consequences, however, to building a city’s population. Larger populations experience greater unhappiness due to overcrowding among other issues. If the level of unhappiness in the city is greater than the level of happiness, one or more citizens will refuse to work in protest of the situation. These unhappy citizens produce nothing but continue to consume resources such as food (see Figure I.1).