What does automatic foreign religion spread depend on?

[Damoklesz]

After getting bored with civ5, I started playing 4 again. I wanted to win a very early peaceful diplomatic victory on low difficulty, but instead I probably had my funniest loss ever.

It was a large map with standard number of handpicked opponents. Everyone had 6+ BasePeaceWeight and 5+ SameReligionLimit, and my base idea was that I will found all the religions I can, to create one big happy world where everyone have the same religion with massive relation bonuses. Obviously I couldn't get both Buddhism and Hinduism, but besides Buddhism I managed to get all religions. I was even lucky to have Buddhism founded right next to me, so I sat back, and waited for it to spread to me, so that I could join this happy world I created.

Well... it didn't. Ever. I had trade routes almost from the beginning, and I never ran Theocracy. When I finished the UN, I kinda felt what was comming. Instead of me, the highest scored AI got elected, then they voted him diplomatic leader. The End.

So my question is, how can I get a foreign religion to spread to me?

I assume that the more religion a city has, the harder it is to spread a new religion there, both with missionaries and by the passive trade route spread. So would it helped, if I settled lets say 5 bad cities without religion? Would these cities have any real chance of getting the foreigh religion instead of one of the 6 other religions I own?

Also, there is an other problem. Lets say, that I only have trade route towards the one opponent that has the religion I want. Obviously he has the chance of getting my religions, but that's usually fine, because he has his own with the holy city, so it's unlikely that he will convert. But can he spread this religion further by trade routes (I assume the AI only builds state religion missionaries)? And if so, what are the chances that he spreads one of mine sooner than his?


Now I realise, that this whole deal could probably be a lot easier, if I just started spreading one of my early religions with missionaries, and try to convert everyone (with tech gifts, if needed). I could gift enough techs to whoever founds the foreign religion so that he would lead in score among the AIs. But this seems way too easy

I always kinda liked religions, but now that civ5 doesn't have them, I started loving them here!

 

[Mantic0re]

Open Borders: Check
Not running Theocracy: Check
Not running Mercantilism: Check
AI not running Mercantilism: Check

I think the rest is up to the Random Number Generator. Presumably each city rolls a check to see if a religion is spread to it via trade routes each turn. I believe that spread depends on the cities it is trading with and maybe the population. Not much you can do really beyond building settlers and increasing the number of cities that can potentially receive a new religion.

 

[Damoklesz]

Yeah, I forgot about Mercantilism. It's late anyway, I'm looking for religion spread way before Banking.

So you really think, that the number of religions already present in the city have no influence on the spread?

 

[lymond]

So you really think, that the number of religions already present in the city have no influence on the spread?

Not sure if I totally follow the context of this question, but I'm pretty sure that if a city already has a religion that the chance of auto-spread to that city of a new religion is virtually nil.

 

[Mantic0re]

I see religion spread to cities containing a religion all the time. The problem is I don't pay enough attention to see if there is a missionary about of if the auto-spread roll was kind.


I expect that the chance of auto-spread gets limited by the number of religions currently present but not fully eliminated until some number is reached.

I think auto-spread can happen with 1 or maybe 2 religions present. I'd be very surprised if it can happen with 5.

Also remember if you have the religion anywhere in your empire you can spread it yourself via missionaries. You don't need a particular city to benefit from auto-spread, you just need one city, any city to get the lucky roll.

 

[Danelius90]

That's right, for a religion to spread naturally (without a missionary) the city can't have a religion present.
Had a friend playing a game and was complaining how he founded Islam and it hadn't spread being a late religion, all other cities had religions already hehe.

With missionaries, the chance of success diminishes with increasing number of religions present in a city, and apparently your own cities have a higher chance of success full stop.

So open borders, trade routes, pray for missionaries

http://www.civfanatics.com/civ4/strategy/religions.php

 

[Damoklesz]

Thx, thats a great article! It clears up so may things. Like that the automatic spread can only happen from the holy city, and that the chance is proportional to the distance from it.

So this makes my strategy seriosly flawed. I mean the chances that a new city of mine gets the only religion which is not mine, must be extremely low, given the fact that the other 6 holy cities are all much closer.

To keep something from my original strategy and win, I'd need to conquer a city, which has the common religion, so I could convert. I'd have to do this about at least 70 turns before the UN is finished, which could make it hard to determine the optimal target (my UN opponent).



By the way, there is still just one minor detail, I'm curious about.

Complicating things further, the Theocracy civic is documented to "prevent the spread of non-state religions. Once again, this doesn't quite mean what it says.

For spontaneous spreading, this is precisely right; your state religion is allowed to flow to one of your unconverted cities (if it is connected to the holy city), but no other religions may do so.

I always assumed that Theocracy works both ways, but the article doesn't say if I can deny my religions from the AI by running Theocracy, or not. So can religion naturally spread form a theocratic civ to a non-theocratic one? If it can, than only the theocratic state religion, or any religion?

 

[obsolete]

There is also a bias, where the most common religion in the game, will be the last one to auto-spread. This is done to prevent one religion from being dominant. This is also what screws over the player when he's out of range from an early missionary spread. He will never get that religion if the others already are sharing it unless by missionary.

 

[Danelius90]

I always assumed that Theocracy works both ways, but the article doesn't say if I can deny my religions from the AI by running Theocracy, or not. So can religion naturally spread form a theocratic civ to a non-theocratic one? If it can, than only the theocratic state religion, or any religion?

I believe (no reference to religion ) that Theocracy only affects your civ, so it prevents religions in AI cities from spreading to yours, even if they are connected.
Just did a quick test on a save and found that:
1. yes, your theocratic society will be able to spread your religion to a non-theocratic one (natural spread)
2. A non-state religion present in a city of a civ running theocracy CAN spread naturally to AI cities

Spoiler :

I didn't cheat here (well apart from using world builder to set it up)
I tried it a few times, and Buddhism spread each time until I put the Hindu holy city there instead. But I guess it should spread a normal religion too...

 

[Damoklesz]

Thx for the testing. I'm not sure how I feel about the results though...

I mean if I think about what theocracy actually means in real life... it really doesn't include anything that would prevent other empires getting or converting to their religion.
On the other hand it would be nice if the player could deny religions from some of the opponents this way. Well, in real life, this wouldn't make much sense either, so I guess I can't really complain.

 

[Charlesbusa]

And I think the AIs cheat. Even on Noble.

Played a game with me and 4 AIs on the same continent. I founded the first religion, christian, and within 2 turns all the AIs had it auto spread to them and converted.

I can't tell you how many games I've played waiting and waiting for a religion to spread. Never ever that fast for me.

 

[Amask]

AI doesn't cheat. I once founded a religion in my capital, and had 5 cities, all connected, sit without one well into the medieval era. Then 4 of them got it on the same turn, and the fifth one got it next turn. It's completely random and goes both way - in your favour and against.

 

[Sian]

I can't tell you how many games I've played waiting and waiting for a religion to spread.

proberly less than you seem to remember ... randomity is random and due to the human brain A, tries to find logic even if theres none, and B, remember bad luck better than good luck then

 

[champ82]

Not that this answers all questions but I thought I’d share this funny thing that happened in a game.

Sitting Bull, who was isolated (he was sort of close to a continent with civs on it but he didn’t meet them until caravels) founded Buddhism. Somehow Buddhism spread to a city on the non Sitting Bull continent. Sitting Bull builds the AP in isolation.

Realistically, I don’t think there are many games where free market v. mercantilism is going to make much of a difference with religion auto-spread. Auto-spread generally happens before banking.

 

[nbcman]

Realistically, I don’t think there are many games where free market v. mercantilism is going to make much of a difference with religion auto-spread. Auto-spread generally happens before banking.

Neither one of those civics make a difference. The mechanic for spontaneous conversion / auto-religion spread is that the holy city and the target city (which cannot have a religion present) must have the potential for a trade route (trade network connected), not the presence of a trade route.

Trade Network connected means almost what it sounds like; there must be a connection between the converted city and the holy city - that is, the cities must be part of the same plot group. Plot groups are determined by explicit routes (roads, railroads), and terrain routes (oceans, rivers, coastline). These latter types depend on which technologies have been discovered by the owner(s) of the cities. Why almost? Because cities can connect through a closed border.

 

[champ82]

Neither one of those civics make a difference. The mechanic for spontaneous conversion / auto-religion spread is that the holy city and the target city (which cannot have a religion present) must have the potential for a trade route (trade network connected), not the presence of a trade route.

Yeah, I was wrong. I read some posts above and it temporarily gave me brain farts.

This explaination seems more accurate but I'm still puzzled over my Sitting Bull example.