
Originally Posted by
JorisofHolland
It is very easy, but you'll have very limited options. In fact, the only benefit of being the Pope is that everyone you attack will be excommunicated. You won't be able to call crusades to your liking, nor will you be able to order ceasfires.
However, if you still want to play them: go to \Stainless_Steel_6\data\world\maps\campaign\imperial_campaign\ and open descr_strat.txt (using notepad or whatever). You'll see a list of factions under "playable" and a few others under "unplayable". Simply move the papal_states from the one to the other and you're done.