Culture-Flipping Exposed

[Dan Magaha FIRAXIS]

Someone over at CivFanatics asked me about this, so I posted this there, figured it might be useful to players here as well...


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In response to the requests I received earlier this month with regards to how "culture-flipping" works, I sat down with Soren, the lead programmer on Civ III, and he explained which factors influence the probability of a city "flipping" and what the relative weight of each factor was.

The base values used to determine the chance of city flipping are as follows:

A) The number of foreign nationals in the city in question (resisters are counted twice), and

B) The number of the 21-tile city-radius squares of the city in question that fall inside your cultural borders.


These numbers are then further modified by a variety of factors, applied multiplicatively. Here those are, in order of importance:


1) The ratio of distances to the respective capitals of both cities. Basically, if you're closer to your capital than the other city is to its capital, you've got a better chance of getting a flip.

2) The ratio of total culture points of both civs. Obviously, the better your culture is versus the opponent civ, the better your chance of getting a flip are.

3) I didn't even know this, but apparently each city has a "memory" and remembers the total amount of culture generated by any civ who has ever occupied it. This is the 3rd most important factor, because if the "attacking" civ has more historical culture in the city than the "defender", the chance of that city flipping to the attacker are doubled. This is one reason that conquered cities often flip back to their previous owners.

4) Civil Disorder in a city doubles the chance of that city flipping.

5) We Love the King (or whatever) Day in a city halves the chance of that city flipping.

6) Lastly, the number of land-based combat units (e.g., any unit with at least 1 point of offensive and defensive capability) in the city in question are subtracted. This factor is relatively low on the totem pole and this shows you why cities can flip even with huge militias garrisoned in them.


Hope this helps.


Dan

[Arrian]

Thanks for the info. I think most of the factors were known, but I appreciate the more concrete info, such as WLTKD reduces chances of flipping (which I knew) by 50% (which makes sense, but now I know for sure), etc.

The one factor I didn't know about is the "number of squares w/in a city's 21 radius that are within your cultural borders" bit. That is interesting, and explains several non-flips I've had - cities that I thought should have flipped to me, but never did. They were spaced so that they got their full 21 squares w/o my culture creeping in. The cities that I've deliberately placed close to AI cities in order to "culture bomb" tend to serve their purpose.

-Arrian

[Aeson]

Very interesting. Next time I'm in a culture war, I'll be sure to plant some dummy cities 1 space away from the AI's cities that I'm looking to aquire. And seeing as how the number of garrison units is such a small factor once resistance is over, it would be best to just keep 1 defender (if even that) in newly conquered cities.

[jackshot]

Extremely interesting, explained a lot for me.

[Darth Sidious]

i have never had a culture flip yet (i just raze cities instead of take em over since i hate the resistance and unhappines, so i just build my own ones)

reading your post, that it goes out of the available city squares and the number of foreighners, being multiplied by the other factors, is my assumption that a city without foreigners will never flip correct?
If so, i can stop worrying about that stupid culture but just stop adding captured workers to my cities.

[Aeson]

I would assume that even if all 21 tiles were claimed, and no foreign nationals, the chance would still be greater than 0%. Otherwise culture wouldn't have any effect.

[solo]

Dan

Very informative, and thanks a lot. Any chance you could do this another time using AI sneak attacks as the subject?

[Arrian]

Info on sneak attacks would be nice to have... just to satisfy my curiousity. It certainly seems the AI does some sort of rough calculation of power, based only on number of units (not quality) and tends to be more likely to launch an attack if you are powerful and in possession of lots of resources/luxuries - basically, if you're winning. But a more exact explanation would be nice.

Also, it seems to me that if you play a more aggresive, warmonging game, so will the AI. I am currently playing such a game (I tend not to be a real warmonger, but finding Beijing UNDEFENDED, with a settler in it circa 2500 bc was just TOO GOOD to pass up). Well, since that nasty little opening, the game has been one war after another... with AI civs breaking ROP's and even MPP's to sneak attack me (poorly, and then get wiped out). I normally don't see that level of backstabbing.

One last thing. Dan, if you're following the thread, I have a request: if possible, I would really like to see my civ's diplomatic reputation, like in Civ II (despicable -> spotless). I bet others would, too.

Thanks,

-Arrian

[La Fayette]

solo
I mean you are greedy.
If Dan and Soren explain everything, what shall we do with our labs?
(part of the fun, at least for me, is discovering how this game works, and I know that I am not alone: if you have a look at my thread 'CiC' on civ2 strategy forum, you will notice that Xin Yu is busy explaining why and how the AI rushbuys in civ2, ...and he's doing that NOW)

(La Fayette, happy to have discovered 'size6', and willing to discover as many other ways to beat the AI as possible)

[Darth Sidious]

i guess that is now replaced by the mood of the foreign people.
polite, cautious, furious, are there more moods?

[Arrian]

Not really, Darth, although your reputation will have an effect on the other civs' attitudes. Ever notice that sometimes civs start out "annoyed" at you? You haven't done anything to them, or anyone else, yet they're pissy. So it's not your reputation - the AI's attitude is also determined by relative power, cultural linkings (european, native american + americans, classical, ancient + zulus), etc. Sometimes they're mad at you out of jealousy - this is a sure sign you're doing well

-Arrian

p.s. I know my request is a minor, minor thing, and there are more important things that need to be addressed first.

[duodecimal]

are these calculations right?

Actually, according to the formula, an opponent's city must either have one of your citizens or must have a tile in its radius within your culture in order for it to defect.

Here's a distilled version of the formula as I understand it, specifically in terms of if an opponent's city will defect to you:

( ( Your nationals in city + tiles in city radius owned by you )*

( Distance to opponent's capital / distance to your capital ) *

( opponent's total culture / your total culture ) *

( If WLT*D, 1/2, else if Civil Disorder, 2, else 1 ) *

( If City generated more culture under your control, 2, else 1/2 ) ) -

Number of opponent's combat troops in city

((Citizens+Tiles) * CultureRatio * DistanceRatio * StatusFactor * HistoryFactor ) - Troops

So, let's say you captured Canterbury for a short time before the English took it back. While it was in your possession, it grew by 2 citizens to total 6, and built a temple and library. Your culture is (let's say) 200; the Brits, 120. Cantebury is 15 squares from London. In the short time you had it, the amount of culture produced exceeded that which it gained under the Brits. They are now stationing 3 spearmen in the city, and, since they haven't rebuilt the luxury infrastructure destroyed during the second war, the city has gone into civil disorder.

Not willing to enter another war just yet, you hope for a cultural flip back to your side and hope to help this along buy building the Forbidden Palace in the city-next-door, only four tiles away. Your borders consume 5 tiles of Cantebury's 21-tile radius.

According to the formula, the odds of regaining the city are:

( (2 + 5) * (15/4) * (200/120) * 2 * 2 ) - 3

( 28 * 3.75 * 1.67 ) - 3 = 172.35

I don't know what 172.35 is supposed to mean. What are England's "odds" of holding on to the city? I'll reverse the formula

( (4 + 16) * (4/15) * (120/200) * 1/2 * 1/2 ) + 3

( 5 * 0.267 * 0.6 ) + 3 = 3.8

3.8 to 172.35 is 2.2%, or 97.8% in your favor. That sounds pretty high... I haven't been paying close enough attention (or fighting enough wars) to know if this seems right.

Let's say that there was no war - your borders simply extend into Canterbury's radius - no citizens, no civil disorder, no wltkd, but your Forbidden Palace is 4 squares away.

( (0 + 5) * (15/4) * (200/120) * 1 * 1/2 ) - 3

Your factor = ( 2.5 * 3.75 * 1.67 ) - 3 = 12.67

Brits...
( (6 + 16) * (4/15) * (120/200) * 1 * 2 ) + 3
Brit's factor = ( 44 * 0.267 * 0.6 ) + 3 = 10.05

So, there's a 55.8% chance the city will defect to you, tested, I suppose, each turn. That sounds a little better to me, but still (in terms of my experience on Regent as Babs) a little on the high side...

Duodecimal

Edit:

Per Mongoose, here's the first calculation without the Forbidden Palace. Let's say your capital is 25 squares away.
( (2 + 5) * (15/25) * (200/120) * 2 * 2 ) - 3 =
(28 * .6 * 1.67 ) - 3 = 25.1

The Brit's calculation also changes:
( (4 + 16) * (25/15) * (120/200) * 1/2 * 1/2 ) + 3 =
(5 * 1.67 * 1.67) + 3 = 13.9

So you have a 64.4% chance of the city reverting, instead of a 97% chance. If the garrison was doubled to 6, the odds of it reverting drops to 52.6% - compared to if you didn't outproduce the Brits in culture in that city - in which the odds plummet from 64.4% to 14.2%! (9.7 : 58.8)

[rflagg]

reversion after death

Quick question regarding this (I also posted this in the help section, but here's probably a better place):

Is there *ANY* likelyhood that a civ that's been wiped from the planet could come back via reversion? I wiped out 3 civs in my current game, and although in most of the cities I'm starving off all the resistors, I notice that even after a civ is gone, his population stays in the city I took over.

But, since the distance to capital = infinite, is there no possibility of it happening, even though my capital is literally across the world?

The reason I ask is right before destroying the Russians (huge earth map) who had their last city holed up in Newfoundland, and my capital on the southern tip of Africa, a city of theirs deep in Europe (a little west of Italy) reverted to them. All they had left was a size two city, 0 culture in that city, one spearman. I thought it was pretty cool that it did happen (made the war more realistic and interesting - I was an evil leader though, and raized the city so I could build my own their), but I was just curious if it could happen after the fact.

If anyone's seen it take place, let me know. Thanks!

-Rflagg.

[Mongoose]

Duodecimal, AFAIK, the Forbidden Palace does NOT substitute for the Palace in cultural reversion.

Anybody that can refute or confirm this? Dan, maybe?

Indeed, I read (at Civfanatics, I think) that somebody lost a city back to its original empire, even after having used a GL to rush the Forbidden Palace therein.

[Xin Yu]

I remember government type matters. Despotism 1%, monarchy/republic 2%, democracy/communism 4%.