I think the key to most players' having problems advancing beyond Prince/King is two-fold. 1) They play too fast. By mid-game (200-300), an average turn takes 5-10 minutes. By end-game (300-400), an average turn takes 15 minutes. I keep hearing stories about playing a game in a night or two, and that's way too fast for a standard sized/speed map game. Thinking a strategy game helps. 2) They don't re-act to the AIs. Every turn, I check my detailed diplomacy tabs to see who likes/hates who, who is building an army, wonder-mongering, city-state mongering; who has resources to trade. This lets me adjust who I want to be friends with, who I want to appease, who I want to piss off, and who I need to keep an eye on. If you just friend everyone who tries to friend you, it'll be a tough road ahead, and you won't have many friends. The AI is a giant calculator, so every time you get screwed, you most likely asked for it. Especially on large maps, alliances and diplomacy is probably the most important path to any victory, allowing you safe time periods to build infrastructure, expand, etc. I've read a number of posts that begin with "why did the friendly AI attack my defenseless new settlement near their borders?". Makes me think most people don't quite get how diplomacy works in this game.