Originally posted by The diplomat
I think that an empire's strength an size should oscillate a lot more. In civ3, a civ always get bigger. You never really see a civ get bigger, then smaller then come back again.
1) larger empires can have more corruption, but more importantly, they need to have higher unhappiness. SMAC had "bureaucracy drones". Civ3 should have something similar. The larger the empire, the more unhappiness, so that the risk of revolt increases. This means that in an extreme case, a large empire could lose cities to revolt and become much smaller and decline.
2) smaller civs need a boost to help them overcome a larger civ. I have a somewhat radical idea to do this. If a civ is really struggling in a certain area, there would be a certain percentage chance that a great leader type unit would appear and give that civ a bonus in the area where it is lagging. The bonus would be temporary becaus the special leader could be killed or in any case, would die of natural causes after certain number of turns. So the Special Leader would only exist for a certain number of turns.
An economic leader might give the city that it is in, a boost in gold. A scientist leader could give the city that it is in, a boost in science output. A military leader could come with 3 elite free units. etc...
The idea would be to give a small struggling civ, a chance to come back into the game. A temporary Special Leaders means that it would be up to the skill of the player to take advantage of the chance.
idea 1 would make it harder for larger civs to hold on to their territory. Idea 2 would help a small struggling civ come back into the game. Therefore, both ideas would favor empires oscillating in strenght a bit more than they do.