I have never commented on here before, but I love DOC, and Ive been on a long quest to win as every civilization (after several years, Im only a little over halfway there). But I came up with an idea, so I wanted to share. I apologize if this something like this has been implemented and I dont know about it; I havent updated my install in a while (worried that those abandoned saved games where Im so very close to completing my UHV, that I hope to go back and win someday, will not be compatible).
Anyway, my idea was that after nationalism, when a faction collapses, it collapses as if it were a human playernamely, back to its core. Without being destroyed.
I feel that this would be realistic. After the concept of nationalism, nation states havent really gone away. After the empire of Napoleonic France collapsed, there is still a France. After the Ottoman Empire collapsed, there is still a Republic of Turkey. These empires lost their imperial lands, but their core (both in a real sense, and in a gameplay sense) remained. Likewise, after WWII, all the European colonial empires essentially collapsed. But we still have England, the Netherlands, etc, as countries. The Soviet Union collapsed, but there still exists a somewhat reduced Russia.
I feel like this would not only enhance the game in terms of historical accuracy, but also in terms of gameplay. Collapsing civilization being eliminated is useful for making room for new civilizations. The Western Roman Empire collapses to make room for the Western European countries (also, the Western Roman Empire was really destroyed); the Ancient Persians tend to collapse to make room for the Arabs, and the Arabs in turn for the Turks. But after nationalism there are few new civilizations, and those that exist are mainly colonial (e.g. United States, Argentina, Brazil), and thus far from any other civilizations core. You dont need to get rid of old empires to make room for new ones in the same way as earlier in the game.
This would also make it harder to destroy civilizations (though not impossible; if at war with a collapsed civ, it shouldnt be too hard to score the coup-de-grace and take their now-isolated capital). I think this is important. In games that I have played that have made it to the 20th century, the map, especially of Europe, never looks like it did historically. And while this is in some sense good (I dont want everything to unfold historically), the reason is many of the large European colonial empires collapse, meaning games with no Spain, or no France, or no Portugal. And the Ottomans always seem to collapse, so there is never an independent Turkey.
Thoughts? Is this possible?
Glad that you do consider about the cultural thing. Looking forward to seeing this included in your later version. 
). I don't want to imply that the current Art is bad, only that there mightbe better and fittingArt:
