Fetch said:
So, assuming I've got enough culture to encompass the 20 tiles, I can work these 20 arbitrarily at any time?
Yes, you can work whichever of those tiles you want as long as it A) Fits in the cross, and B) is encompassed in your Civ's culture. So like Voice was saying ... you can start a new city nearby another city, and with the large culture of that other city, you could work tiles you would normally not be able to work with a starting city's weak culture.
For example, suppose I've got a pop of 3, but have had 2 culture expansions. Can I work 2 tiles that touch my city and a 3rd that does not?
Yes, you could even work 3 tiles completely away from the city.
I'll try to draw a better example, but it's tough with the text restraints:
C= city
+= workable spot
X = unworkable spot ... too far from the city.
|X|X|X|X|X|X|X|
|X|X|+|+|+|X|X|
|X|+|+|+|+|+|X|
|X|+|+|C|+|+|X|
|X|+|+|+|+|+|X|
|X|X|+|+|+|X|X|
|X|X|X|X|X|X|X|
As long as the culture incompasses the "+" squares you can work it, with no other restrictions. (Well other than moutainous terrain or whatnot). You can stretch cultural boundries either by building culture improving buildings in that city, or by building close to another larger city, which already has large culture.
Some times you can get a "streched" culture effect if you build a new city fairly close to an older one. You culture will "span the gap" and look something like this: (& = workable tiles, in stretched culture, so same as +'s)
|X|X|X|X|X|X|X|X|X|X|X|X|
|X|X|X|X|X|X|X|+|+|+|X|X|
|X|X|+|+|+|&|+|+|+|+|+|X|
|X|X|+|C|+|&|+|+|C|+|+|X|
|X|X|+|+|+|&|+|+|+|+|+|X|
|X|X|X|X|X|X|X|+|+|+|X|X|
|X|X|X|X|X|X|X|X|X|X|X|X|
Kind of hard to see, but I hope that makes sense. Remember, that will still have access to all 20 +'s once the culture encompasses them.
And if you can only work these 20 tiles, cities should always be place within 2 squares of a resource, assuming you want to work it?
Yes and no. Depends on if you want just the resource, or if you want the tile bonus on top of that. Usually you will want both, so you build it within two tiles. Sometimes, you might want the resource itself, but also a more favorable terrain spot (like on a coast), so you can build it three spots away or more. Once the culture expands past the resource, you can build the improvement on it and get access to the resource itself. But you won't get the tile bonuses (like added production or food) in the city. You will however get any +health, +happiness or whatever the resource itself provides in all cities that are connected to that resource by a road.
I find this useful for luxuary items like gems. Sometimes I'll get 3 resources like food, ores and gems close to each other, but they aren't close enough to encompass in the 20 squares of the fat cross. In this case, I let gems slide, and build the city near the other two. After building a few culture buildings the borders will stretch past the gems, and I can mine it, and link it up to a road to get the happiness bonuses.