forum.freeciv.org

This is based on an idea I gave in another post, but this is a more simple version of this idea: basically, I think it would be interesting to allow cities to revolt and form another nation (aka, a new player) when they aren't managed properly. Bascially, this would happen if a city went into disorder, for any reason. This city would become the new player's capital, and all of it's buildings (including any wonder and it's effects) and home unities would belong to this new player as well (this new player would also have all the technologies that you had at the time of the revolt, as well as your explored map so far). Diplomaticaly, naturally this new nation would start as your enemy, and one pretty hard to appease.
More specific points of this idea should be discussed, for example, how exactly are the parameters to determine if a city becomes independent or not (how many turns in disorder, how much of the treasure this new nation should receive, etc.)

This should absolutely be implemented ONLY if cities revolt often. One or two revolts can happen to anyone, but only if it is persistent, a revolt should grow into a rebellion. And if that is the case, it will have effect only on low-experience players because players with even moderate experience are able to see the revolt coming and prevent it before it happens.

Yes, I was thinking about more than one revolt. To be fair, I just wanted more reasons to prevent an empire from growing too large, or to last forever (sooner or later, all empires will fall)

That's why there is "unhapiness due to size".

Yes, it would be only a matter of adding this "revolutionary city" feature. Do you think I could add this editing some rulseset, or I need to edit the source code?

I don't know that.