Question on Alphabet and Astronomy

[Jabba]

It has been a while since I played and I am trying to figure something out...

The description for Alphabet says that it is needed for tech trading, while Astronomy is needed for cross-ocean trading between cities.

Do these restrictions still apply even if the civilization that you are trading with has already discovered Alphabet or Astronomy?

I have not discovered Alphabet yet, and yet the civilizations I meet all have technologies on offer.

I have not found their cities yet, but If I send off an explorer will my cities start trading across the ocean? I have not discovered Astronomy yet, but they all have.

 

[Dr.Null]

If ONE civ has the requisite tech, it can trade with ANY other civ, including a civ which lacks the requisite tech.

This is why it is a commonly known tactic to tech Aesthetics and trade it for Alphabet.

 

[Jabba]

Thanks. And it is the same principle with Astronomy? I can trade across the ocean with the cities of civilizations that have discovered Astronomy even though I haven't?

 

[Jabba]

A related question: for trade routes to be established between civs, do both civilizations have to know the location of BOTH cities in the trade route?

I.e to get trade routes established do I need to reveal the location of my cities, as well as discover the other guy's?

 

[Choggy]

You can tech trade with anybody with Alphabet, irrespective of where they are on the map. You can only trade resources across oceans with Astro. Other civs can trade resources with you when they get Astro but if you don't have it you don't get the benefit of ocean trade routes, they do, so be careful of offering open borders to AI civs that meet you if you you haven't got Astro yet.

Getting Astro first gives you a huge commerce benefit with civs on other continents. You get some fantastic trade routes and you can get silly amount of gold from them in exchange for resources. That's why a lot of people beeline it on Continent-type maps.

 

[Jabba]

Thanks.

 

[Jabba]

A related question: for trade routes to be established between civs, do both civilizations have to know the location of BOTH cities in the trade route?

I.e to get trade routes established do I need to reveal the location of my cities, as well as discover the other guy's?

I am still rather curious about what (in terms of geographic knowledge) makes a city eligible for overseas trade. Having now discovered Astronomy, I see that my cities are trading with foreign cities that I have not discovered yet.

Is this, I wonder, because my cities have been discovered by the foreign civilization?

Other civs can trade resources with you when they get Astro but if you don't have it you don't get the benefit of ocean trade routes, they do, so be careful of offering open borders to AI civs that meet you if you you haven't got Astro yet.

I am still a bit puzzled by this. Are you saying that when I open borders with an overseas civilization that has discovered Astronomy when I have not discovered Astronomy, his cities will trade with my cities, but my cities will not trade with his cities? So the trade route is in effect one way?

Seems odd, but very useful to know if true.

 

[Kesshi]

I am still a bit puzzled by this. Are you saying that when I open borders with an overseas civilization that has discovered Astronomy when I have not discovered Astronomy, his cities will trade with my cities, but my cities will not trade with his cities? So the trade route is in effect one way?

Two things are needed to trade overseas.

1) Astronomy (you know this.)
2) A known route.

Astronomy needs to be known by only one civ.
The route needs to be known by only one civ.

Trade is always potentially two-way. You may not be trading with every one of their cities, but if between the two of you, both of the aforementioned conditions met then trade is possible both ways.

Also, you "know" that the other leader's city exists. You may not know its exact location, but you know it is there. Talk to him in the diplomacy trade screen (ctrl-click on the leader's name) and you will see a list of his or her cities.

 

[civac]

I am still a bit puzzled by this. Are you saying that when I open borders with an overseas civilization that has discovered Astronomy when I have not discovered Astronomy, his cities will trade with my cities, but my cities will not trade with his cities? So the trade route is in effect one way?

Seems odd, but very useful to know if true.

Yes, that's how it works. And, indeed, it is odd.

 

[Tristan_C]

I am still rather curious about what (in terms of geographic knowledge) makes a city eligible for overseas trade. Having now discovered Astronomy, I see that my cities are trading with foreign cities that I have not discovered yet.

Is this, I wonder, because my cities have been discovered by the foreign civilization?



I am still a bit puzzled by this. Are you saying that when I open borders with an overseas civilization that has discovered Astronomy when I have not discovered Astronomy, his cities will trade with my cities, but my cities will not trade with his cities? So the trade route is in effect one way?

Seems odd, but very useful to know if true.

The trade route is indeed one way. You are "exporting" to him via astro. The rival city to which you have an overseas route cannot create an overseas route of its own until the rival civ gets astro. You will also export to cities you haven't found, if they are roaded to a city you have found.

Being an importer has no positive or negative effect on your own civilization.

Yet it can happen (though it is rare) that adopting mercantilism will deny a large commerce boost to a lot of rival civs. If you are an island nation and all the civs on the mainland are exporting to you, mercantilism will force them to revert to their less-profitable land routes instead. Check the demographics screen; it tells you how much you are importing and exporting.