also, dont assume the same tactics that worked in civ3 will work here. one of the biggest civ 3 habits i had to break for 4 was the plantin cities until forced by the other civs not to.. the corruption, waste, and all that (for lack of right words in 4) will reduce you to simply a large backwater empire to be conquered by the others. You MAY get off to a good lead, but when your science research is 10-20%, the others will overtake you very soon and you cannot do anything about it, because your cities are defended by warriors, maybe archers and they are attacking with riflemen!! If your research dips below 50, slow down man.. slow down big time. (hell, if below 70 some may say).