Improve Diplomatic AI.
Dont let it make his decissions by numbers So you get random decleration of wars...
In my current game I know 14 of 22 civs, of those 14, 11 are at war with me, which very is unrealistic and stupid.

The real funny thing is that it is only the Middle Ages. So yeah, for the upteenth time Firaxis, please do something about the games AI system. I am getting to the point, where I am just going to play another game, maybe EUIII for awhile, until stuff in CiV gets fixed.
1.) The game needs a complete revamp of the diplomatic system. Talk to some Historians and take what they say into consideration. This warmonger status needs to be eliminated. Diplomacy just makes no sense. I have had most civs declare war on me, many who have no true direct contact, and many of whom I am no direct threat. These DOWs have no face value, they are meaningless and stupid, and it makes the AI look dumb, because it does the same stupid decision making process with each civ in turn, and that is to declare war for no real reason. In my game, I have declared war twice with the same civ, and took over one city state for iron, otherwise I was doomed. Far, far, less beligerent than the AI civs have been to each other, and to me. It seems it is ok for the AI civs to dogpile each other, and have countless wars, which they do, but if the human player tries it, he is the warmonger, the bad guy! Come on, it is absolutely ridiculous. Diplomacy needs to change. I am getting sick of spending money on a game that never gets fixed.
2.) The AI is better at tactical warfare, from where it used to be. I have even seen it support each other with ships. Spanish triremes are on station supporting Greek triremes, something I have not seen before. I moved one of my ships and the fog of war lifted, and I realized my ship was now outgunned four to one. That was interesting, and I hope the AI obliterates my ship, but I had to sacrifice it to see what was hidden out there. The AI should be better at capturing cities, and be better, much better at amphib operations, using correct tactics, and escort vessels.
3.) There should be some new game mechanics added to give the game more depth. Right now, it is only interesting for me to play a domination victory setting, all the other victory conditions are boring. I feel a conquest victory should be added, or some military mission victories. For instance, if you conquer so many civs in so many turns you win. IDK something interesting. As far as game mechanics, I feel espionage, religion, or some things similar should be tried out to see how they play out. Diplomacy, and AI has to come first, so they work properly, before any more things are added. If the AI cannot handle what it has on its plate already, how is it supposed to deal with more?