Just finished an experimental wide culture game in the
HOF Emperor Cullture Challenge. Finished turn 1901 AD (turn 321), better than usual for me, but not my personal best. I took a screenshot of my culture production at turn 300:
Breakdown:
- 457 in the capital
- 146 in puppets
- 101 from excess happiness and city-states.
- 704 core culture (capital + puppets + other sources)
- 740 in eleven settled cities
- 1,444 total culture
- 1,732 Golden Age culture
I used two guidelines to judge whether my settled cities were pulling their weight: the 10% of core rule, and the N+9 rule. (I didn't calculate the Bonus/9 guideline as the relevant data is harder to get from the user interface.) I'm ignoring the Golden Age bonus in the discussion below, to allow for simpler comparisons with the Economic Overview screen, which also ignores it.
The 10% rule notes that each city increases policy costs by 10% (with Representation), so unless the cities also increase culture production by 10% or more, they will slow you down. In this example, the empire produces 704 "core" culture per turn from the capital and other non-penalized sources. To avoid a slowdown, the eleven settled cities must produce
70.4 cpt each or 774 cpt overall.
The N+9 rule states that a new city is counterproductive unless it can promptly produce more culture than E/(N+9), where E is your empire's total culture and N is the current number of cities. In this example, you wouldn't want to found a 13th city unless it could produce more than 1,444/(12+9) =
68.8 cpt. You can also calculate the value for an existing city as (EC)/(N+8), where C is the city's culture, but the simpler formula makes for a close approximation.
Not too surprisingly, every city with a world wonder beats the guideline, thanks to Reformation. What I do find surprising is that even the wonder cities can only pay for themselves because of Reformation, Representation, Cathedrals,
and weak core culture (300+ turn pace). Remove any one of those factors, and even the best cities have trouble covering the city penalty.
Now the good news for wide culture: Even though the extra cities didn't help me with culture, they didn't hurt much either. The city penalty in this example is about 774 cpt, and my cities covered 740 cpt of it. My twelve-city empire was only about 2.5% slower than its one-city equivalent, and the extra bulk gave me significant military and economic advantages (not sure about science). Also, the slowdown only happened in the second half of the game: In the early game, the extra cities consistently shaved a turn or two from my policy times.
In conclusion: Twelve cities are excessive for culture victory, but 321 turns still isn't a bad time. Three to five cities seem optimal, but only with aggressive cultural policies
and religion. Otherwise, use as few cities as you can get away with.