I'm intrigued by the civil war system in Rome II. I've seen people say that their campaign was effectively ended by a civil war, since the rebel faction got their best armies. I've seen people say that a civil war was not really challenging. I'm interested in what players can do to set up a civil war which would be challenging, but not game-ending - and any tips about how to do this.

My initial reaction to the politics system was to find it confusing and to turn it off, using a 'No Civil Wars' mod. On reflection, I think that was a mistake. Like realm divide in Shogun II, civil war looks like a way to make the mid-to-late campaign more challenging. It is, of course, historical. Large ancient empires did tend to break up, as the successor states of the empire of Alexander the Great have already done at the start of the Grand Campaign.

Looking online, I've found the basic information on how civil wars work. The risk of civil war rises when your empire expands, but falls if you maintain a balance between the different political parties in your faction. When a civil war happens, it seems that if your armies have a mix of generals from your party and generals from the other party, then the other party's generals become the rebels. If you only have generals from your faction, then it seems that some of your generals will defect. It also seems that generals who rebel convert the regions which they are in (and any agents in those regions) to the rebel faction.

It seems that setting up a challenging civil war could involve:-

- Balancing the leadership of your armies, with some generals from your party and some from the opposing party.

- Balancing the strength of different armies. It's tempting to keep using the same army so that it levels up (I like the army traditions system) and to fill this army with my most powerful units. However, if this army defects to the rebels, then I might have created an enemy which I cannot defeat.

- Assigning armies led by 'other party' generals to a specific region of your empire, if you would like a scenario in which part of your empire is trying to break away from the rest.

I wonder if people would be willing to share tips and experiences on how to have a challenging but not unbeatable civil war? I'm also intrigued by the line in the official advice on the politics system which says:

If you have too much power you will end up having to fight a civil war against separatists; too little and it will be against those scheming to take advantage of your political weakness in an attempt to oust you, snatching the leadership for themselves.
I wonder if a civil war against separatists actually works different from a civil war against an opposing party which has become too powerful - does anyone have experience of both kinds (if there are separate kinds)?