A tall empire is an empire with few cities that have high population, whereas a wide empire is an empire with many cities which have fewer population. They're basically the different ways of filling out your happiness potential.
As for which is better, this of course depends on the Civilization you're playing (some have abilities that favor one over the other; India is the most obvious case) and the map you're playing (sometimes you just don't have a choice but to settle with few cities). Tall empires are usually better for cultural victories.
There's more to it than that, but that gives you an idea. If you want more info, I'll leave that up to someone who knows the subject matter more than I do :)
Going tall is much easier and more of a certainty. Easier to control happiness, manage resources, defend, build up infrastructure, gain culture, hog wonders, not peeve off the AI (though it will happen eventually). You will have decent gold and science output until you've squeezed as much as you can out of your cities.
Going wide has better potential. You have access to more resources and better positioning. By claiming land, you'll be denying the AI of it. IF you can keep happiness under control, you'll probably end up with a bit more science and gold per turn later on. But the AI is gonna be gunning for you, and it can be fairly difficult to keep happiness under wraps until you can finally turn that corner. Isolating yourself by say taking over a continent makes being wide a lot easier. Going wide when doing Earth map and starting in Europe/Asia can be quite challenging cause once you get so big, the AI will snap on you and you'll have like 3 people out of the blue declare war on you.
I usually always go tall so I can use up the land. I mean, each city can use up every plot of land I can. So when my city grows big. it will work at max efficiency and the rest of civilians can work in the buildings. Unfortunately, this is hard to achieve, so I just space my cities 3 spaces apart all the time.
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cwjakesteel posted... I usually always go tall so I can use up the land. I mean, each city can use up every plot of land I can. So when my city grows big. it will work at max efficiency and the rest of civilians can work in the buildings. Unfortunately, this is hard to achieve, so I just space my cities 3 spaces apart all the time.
Three spaces apart? I don't think you could build cities that close.
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