Originally Posted by
QuintusSertorius
I don't think you quite appreciate how impossible it was for the ancients, with the tools they had at their disposal, to keep public order in a region as large as our provinces. They weren't just "slave revolts" the local peoples had their own grudges against whomever the ruling power were, various factions vied with each other for control (with ancient enmities mixed in for seasoning), there were cross-border raids by neighbouring people for cattle and horses (or slave-taking). Piracy and banditry were rife wherever central authorities weakened, or were distant. The modern world is nothing like the ancient, any state's hold on the people in an area it nominally ruled was tenuous.
It's not a "random screw you" and has nothing to do with player agency (not least because the revolts script affects the AI just the same), it's about the context that existed. To get to the specifics of the mechanics, there is a 6% chance of a rising occurring each turn (7.5% chance for Troublesome Regions). When they happen, they won't happen again for at least another 50 turns (25 turns for Troublesome Regions). Most of the stacks that spawn are only 5 units, occasionally it's 8, neither of those are "massive rebellions" they're small risings. If you keep sufficient forces on hand to police your interior, they shouldn't cause you any problems.