Great experiences, use numbers. Most of the posters seem to say CD + trader is great, it works for me. Fine, but thats not the same as proving its optimal. eg: Great, totally agree with those benefits as that investment grows over the course of the game. But to make a real point you have to prove that it is better than alternatives, not just the sadly nerfed IZ which I conceded immediately isn't better than a CD. Compare it to a campus or an encampment or a harbor. all of the advantages of a CD and a trader are there to be traded off with. eg: Try this: a settler instead of a CD + trader = more prod and food and gold after how many turns (accounting for the lost pop of course)? Ok so you argue i already settle everything so its moot or i conquor all the peoples so all i do is build infrastructure, then how about more housing ---> more pop > trader. For how long are more worked tiles equivalent/better/cheaper than a trader +CD? so what, perhaps granary > trader? I dunno, someone do math, i'm an ideas guy, too old for math. Again, this is a thought experiment challenging the current orthodox, I dont claim it to be true so much as wonder if it might be. We can all win the game easily with any open or district choice... And a note on victory conditions - in my experience almost always the open is the same regardless. You dont need theatre districts in every city from the start to win culturally, nor do you need campuses to win science, or even holy sites (obviously you need a reasonable religion founded...) to win religious. Those all come much later. The choices I make on what to build first are almost always map and to a lessor degree civ dependent. All this said in the end I do build CD in most cities, but I dont prioritize it like other people and I certainly dont believe its the certain always best district.