If you play the Standard Scenario you generally have a basic level of understanding how the game is going to play out, which was our goal - to make it a challenging experience that relies on your learning the patterns of the world. Manipulating the nations that hate eachother, targeting wise kings, timing a crippling famine at the right moment - but even inside that structure there's so many explosive elements. The moment you take a "radical" choice like killing the King and his immediate family, you get the unexpected - like one time I had cursed the King's Family, the Barons declared him unfit, split into two nations, and began to fight a civil war. Meanwhile the Tribes had united behind a Hero, who they proclaimed their chosen king, but he was Cylarian, the barons have a diplomatic summit after a bloody battle, declare the Cylarian hero their king (I didn't see this result but I'm assuming its because he is friends with all the barons and the heroes that were acting as diplomats), making him the king of both powers, he then went on to marry the daughter of the elves (at this point he's simply a diplomatic monster)... overthrows the Elvish Council and declares himself King.... now his ego and diplomatic skill are both max, he manages to Annex Elerion into Cylaria (still only three crowns) - I'm just watching this happen, because I'm spellbound, I don't want to interfere because I need to know what can possibly happen. The united three kingdoms attack Arden, recapturing the farmlands, he makes peace and turns Arden into an ally.
Long story short, he discovers I'm rising and crushes me. Despite the fact that he was simply taking over the world he was friendly with every hero, so no one was stopping him. I ended up adjusting how heroes see other friends if they're growing too powerful, but the completely random events that lead up to this were otherwise "expected" to function that way. In addition, later builds implemented the Balance of Power desire which makes nations take a more critical eye at people who are growing stronger.
Now that's an outlier but still somewhat understandable based on the scenario setup, if you add in the Game Modes you get some real crazy stuff. I have a lot of favorite Modes, but on the North Burns playing with "Liberty" is a really fun way to switch it - it makes revolutions and slave revolts much more common and you get to see the world rip itself apart and remake itself.