A few months back I wrote about the rhetorical position taken by the Civilization series. This post cascaded into a desire to teach a course that blends historiography and historically-themed games and while I am not here to announce that I am teaching such a course, I recently found myself again thinking about these issues.
Strategy games operate on economies based largely on resources. The Total War games have a monetary economy paired with population, where the population is necessary to recruit troops, but the real limitation is money that acts as a proxy for all necessary resources. The Age of Empires series used the quartet of gold, stone, food, and wood and included trade and a supply-and-demand marketplace mechanism to manipulate your resource stockpile. Food was the most common resource so long as you had access to wood because you could continually build farms, but maps were finite and so were resources.
Civilization is different. (I am using Civ 5 as representative here.) At first there is stone, wheat, grapes, wild animals. Wood mostly exists for the energy used in construction, which then speeds up building the civilization. The other resources are not immediately usable, but they are visible. As the civilizations progress through the ages, resources become available. Horses, iron, coal, oil, aluminum, and finally uranium. In each case, the civilization constructs the human apparatus (pens, mines, plantations, wells) to exploit the resource, with each location providing a variable amount. Once the resource is exploited, it is available until used and reclaimed once free.
From a game-construction perspective, this makes sense. The long version of the game spans thousands of years and has multiple win-conditions, including technology and culture. Conquest, which is the core of the other games mentioned above, is just one possible outcome. Resources are necessary to achieve any of these conditions and streamlining resource management improves game play. Civilization does offer a facsimile of colonization to find new resources as settlers move into uninhabited lands, but sanitizes the concomitant exploitation. At the same time, though, it is possible to win with only minimal expansion because all resources are permanent.
Just as there is no slavery in Civilization, neither is there rape of the environment outside the gradual reclamation of swamps and forests for their exploitation by humans.