I originally posted this on the 'Civ4 Lounge & Ideas' thread.
1. Government: I believe that they should bring back the senate from CIv2. The Senate would be used to represent the peoples will in decisions, so if you go against the senate, you cause civil unrest.
2. Civil War: I think that another Civ, or your own negligence could trigger a civil war. Lets say you control a large Despotic empire. You've learned of other governments, and your people yearn to change, but you do not. If you inflame them enough, half of them, normally the less well off half, would split off and form a new capital in the largest and best city that they control. They get an automatic government change, and you can offer to pursue war to bring them back to you. However, another civ could take advantage of this, and side with the rebels and fight for them, taking advantage of your weakened status. It would add another level of depth to the game, though it wouldn't be too fun to be caught in the said situation.
3. Religion: I believe that religion should be worked into the game like governments, each effecting your civilization a certain way. Here would be some prime candidates:
Greek Pantheon
Egyptian Mythology
Norse Mythology
Zorastorianism(I think that is how it is spelled)
Roman Mythology
Shintoism
Taoism
Buhddism
Islam
Judaism
Chrystianity
Each would have its own benifits and problems. Lets say Norse Mythology, being that the Norse were warlike, would give your units a fanaticism bonus in battle, but citizens would be easy to convert to other religions when captured by a rival. Followers of Islam would get the same fanaticism bonus, but couldn't be converted easily, and were intolerant of infidels, creating great civil unrest in your cities. Feel free to post your thoughts on this subject of religion. Anyway, If you change religion, the Conversion would start in your capital and slowly work its way out, picking up speed as it went. More easily converted religions would go quicker, but others, such as Islam, would slow the process. Greek Pantheon followers are tolerant of other religions, so Converting from them would be quicker and less painful. Depending on empire size and religion, it could take anywhere from five to one hundred turns to fully convert. Also, religious civs would take twice as long to convert, as they are fervent followers of the current religion.
4. City size: I believe, that once a city reaches a certain size, such as size 30, it should cover up the surrounding squares, turning them into part of the city. The city would cover up a total of nine squares, but would get resources from up to 28 squares, as shown in this diagram
[Z]=Unused
[X]=resource square
[o]=City square
[Z][Z][X][X][X][Z][Z]
[Z][X][X][X][X][X][Z]
[X][X][o][o][o][X][X]
[X][X][o][o][o][X][X]
[X][X][o][o][o][X][X]
[Z][X][X][X][X][X][Z]
[Z][Z][X][X][X][Z][Z]
Thank you for bearing with me.
.) Basically, it is just a logical advance on what is occurring now. And besides, most games end before the modern age anyway.
