My idea for the "government changing rules". When a government is changed, the moderator will roll a dice, and decrease the result by the stability level. If the final result is more then three, then civil war it is (it will be actually fun to see a hardline vs. liberal civil war in USSR). If less then three, then the coup is not too violent, and the new government is installed. If the final result is less then two, then the stability is not decreased (if its three, then stability is decreased by one point to simulate the fact that not all people accept the change).