The most recent version of Sid Meier’s Civilization video games adds city-states, independent agents that never grow beyond a single city and are never in contention for overall victory, but can help, hinder, or serve as a buffer between the “great powers.” My strategy game Strategic Primer has something similar in its design, which began as an idea at least five years ago.
In the campaign version of Strategic Primer (the computer version is nowhere near the point of adding them yet), these “Independents” serve much the same purpose. While world domination is not the explicit win condition of Strategic Primer, players are likely to come into conflict, and independents, like “AI” players, will help make things more … interesting. Because territory isn’t (in any SP game so far) handled as it has been in the last two Civilization games, the “buffer” effect shouldn’t be as pronounced, but the “independent” powers can either help or annoy the players.
In Civilization, which is after all modeling history and, well, civilization, these independents are of course city-states. In Strategic Primer, however, at least so far I’m just trying to model the military side of things, with each player controlling a network of military fortresses under his or her control, not a country full of cities with citizens to appease. Similarly, many if not most of the “independents” are military outposts. But some are towns and cities, which will present their own benefits and challenges to the players.
Another difference between independent fortresses and cities in Strategic Primer and city-states in Civilization is that city-states are obvious and declare themselves as such in the latter, while in Strategic Primer everyone starts out with only one fortress and building another is a somewhat major undertaking. If a player’s explorer finds a fortress commanded by Philip of Macedon (to choose a suitable name at random), there is no way to tell whether Philip is a “Great Power” or an independent.
On the other hand, the one major difference between the main “AI” players and the independents in this campaign is that I run a full strategy for all of the AI players each turn, but I don’t even determine what sort of fortress or city an independent is until it is discovered by a player (either human or “AI.”) This is partly because I’d rather limit possibly wasted work, but largely because in the present campaign the independent fortresses and cities appear as “events” that explorers can discover, like veins of metal, ruins, or caves, so I’d have to go to some effort to find where the independents are before they are discovered. In future campaigns I expect to run them more like standard “AI” players (and things explorers can discover will be handled better too).