I've had this game for quite a while, but just a few days ago, for the first time ever, I found out that if you click on the face of an AI in the foreign advisor screen, it will show you what specific items that AI needs that you have (and that other AIs have). Previously, whenever I went to foreign advisor screen, it always showed me what resources/techs I have that at least 1 AI does not have, but I never knew how to figure out WHICH AI needs what. At least not without going to talk with every single leader and seeing what shows up on the trade screen. This makes it so much easier. lol I only discovered this by accident, as I didn't mean to click on a face but did so, and then was shocked to see that the information on the screen changed. I don't see how you are suppose to know that this is a feature, it's not obvious at all (to me at least). What features took some of you years to find?