Some really interesting ideas , here my opinion on some of them: 3. (Ive number your list) I think an espionage is the way to go. Ive put my ideas in a post a couple of post above this plus links to other ideas. It basically mimics cold war nuke counting and proliferation. 4. Isnt this already in the game? I think that perhaps resources should perhaps alther in value as the game progressive, a bit like the Whaling and furs. Trading relations arent that important in the late game. 5 & 8. I may be wrong but are you suggesting and interconnection between the type of civilisation, the buildings, whether religion and culture is important, the number of units, diplomatic position, to whether civics are available to you? For example, to get the State Property, Universal Suffrage and Free Religion could only be accessed once a few turns of ferment passed whilst using say, Monarchy, Theocracy, Serfdom in conjunction with poor health rating and too much emphasis on finance and production. Only after the ferment can you revolt to the new set of civics. Another example could be that a police state could not exist without the necessary number of military units / population within a civilisation. This seems like an intriguing but extremely complicated idea. It would certainly mimic reality more accurately. 6. Cultural borders are usually pretty stable in the late game unless you've totally neglected culture. I don't think any alteration is necessary to be honest. 7. It would be extremely insensitive, although inevitable due to modding, to introduce a terror and its derivative insurgency into a fun computer game like Civ 4. Im sure the game developers agree with me. I dont wish to offend anyone, but terror, which is barbaric and horrendous on a personal level, could be seen as defined as much by the victim state as well as the perpetrators. Anyone who has read ORwells 1984 knows full well the use of terror and fear by the totalitarian government, therefore terror could easily be interpretted as civic related. For this reason I think it should be kept well out of the game. And also, not to be corny, one mans terrorist is another mans freedom fighter would become especially apparent. On the otherhand, my proposed ideas for espionage would in many ways function in terroristic way whilst maintaining soveriegn status of the perpertrators e.g. a weakened civ might use Bio, nuclear or sabotage as the only recourse left to themselves to win the game.