A bunch of threads have been shooting around lately about Influence, how to deal with His Holiest of Holies (el Padre), getting peace treaties, etc. I thought it might be helpful to consolidate some wisdom in one thread, maybe get it stickied some day.

Some questions I have...

1) Why, even if I'm allied to a faction, will that faction not consent to marriages?
2) Why can the Pope excommunicate you and still be allied to you?
3) Is there a way to win indulgences from the Pope?
4) What factors determine the threshold beyond which no faction will make peace or ally with you anymore?
5) Why will a faction allow me to continually marry their princes even if we are not allied or may even be at war with eachother?
6) Where are the data files that determine the AI's decision making when it comes to diplomatic agreements (including wedding proposals and the like)?

Some answers or clues I have...

a) going on Crusade, and maybe just successfully completing them, at least in GA, does seem to win you some Papal indulgence, as the GA Crusade description actually states. I have been in situations where I have forbade Crusades to enter my lands and still not gotten excommunicated.

b) I recently had a game going where I (England) was at war with France (big surprise) and could not get them to sign a peace treaty, even though they had taken Anjou, Normandy, and Aquitaine. I got fed up, so I took Flanders. That still didn't bring them to the table.

Then I started raiding Normandy constantly, winning every time, then retreating my raider force back to Flanders. After several years of this, the French suffered some minor rebellions, all of which the quelled. After that, they agreed to end hostilities. On the next turn we were allies.