how do foreign trade routes work?

[Sonnybonds]

why dont i have foreign trade routes? i have open borders and have sailing discovered. but i dont get foreign trade routes with my neighbour? why? i have a city at the shore and so have my neighbour. Do you have to discover the compleet shoreline between the 2 cities?

I play BTS and i have writing discoverd and sailing

 

[JujuLautre]

Three thngs to consider:
- if you can reach from one city to th other by coast only, you need sailing. If you cross ocean, you need astronomy. And in both cases, you need a clear path between both cities.
- the computer automatically calculate the best trade routes. perhaps another one is just better
- and actually, you need currency to have at least one trade route per city.

 

[Stolen Rutters]

-The connection must be complete, by coast, by river, or by road.
-If there are unrevealed squares blocking your way (or coastal Barbarian city or other civ with no open borders with you), you don't get a trade route.

You start with one trade route available, but you need a city to connect to. Currency gives you an additional traderoute .

 

[Eunomiac]

Do both civs need to have the tech in order for one of them to profit? If I have Astronomy and a direct path to a civ on another continent, does that civ also have to have Astronomy for me to have a trade route, or does Astronomy only determine who profits? ... I mean, if I have Astronomy and he doesn't, do I get the trade route income to his city but he does not?

 

[Sonnybonds]

there might be an icetile between me and my neighbour. does that block the trade route? hope not icebergs dont melt in civ4.

 

[LlamaCat]

- and actually, you need currency to have at least one trade route per city.

no actually Currency just gives you 1 extra trade route, it's not required to start having some trade routes in the first place.

I believe both you and the trade partner need Astronomy to have a trade route because all kinds of trading have to go both ways in Civ. That's why it's a good idea sometimes to give or trade Optics and/or Astronomy to another civ, so they will be able to start opening up trade routes with you.

Also make sure you are not running Mercantilism, which closes down all foreign trade routes.

 

[Sonnybonds]

no actually Currency just gives you 1 extra trade route, it's not required to start having some trade routes in the first place.

I believe both you and the trade partner need Astronomy to have a trade route because all kinds of trading have to go both ways in Civ. That's why it's a good idea sometimes to give or trade Optics and/or Astronomy to another civ, so they will be able to start opening up trade routes with you.

Also make sure you are not running Mercantilism, which closes down all foreign trade routes.

is this the same for foreign trade routes on an island? maybe thats why i dont have them because my neighbour needs also writing and sailing.

 

[LlamaCat]

is this the same for foreign trade routes on an island? maybe thats why i dont have them because my neighbour needs also writing and sailing.

yes any cities separated by ocean must have Astronomy for trade routes. if your neighbor does not have Sailing, he does not have Astronomy.

 

[KMadCandy]

Do both civs need to have the tech in order for one of them to profit? If I have Astronomy and a direct path to a civ on another continent, does that civ also have to have Astronomy for me to have a trade route, or does Astronomy only determine who profits? ... I mean, if I have Astronomy and he doesn't, do I get the trade route income to his city but he does not?

if you have astro but he doesn't, then your cities benefit from trade routes with his cities but his cities don't. that's part of why being first to Astro is so incredibly powerful! he can ask you to trade for resources, but there again he's piggybacking on your brains.

you need open borders for city-city trade routes (altho the OP said he had them). you don't need open borders for resource trades (as long as there's a trade route connection, sometimes closed borders with civs on the pathway can mess that up).

 

[Stolen Rutters]

- Ice will block a trade route.
- Unexplored tiles will block a trade route, up until the open border. You don't need to explore all the cities you trade with. You just need a valid trade path to their border.
- Closed borders will block a trade route. If a civ founded a city on the coast between you and your open-bordered friend, you need to open borders with the civ in between in order to get a coastal trade route to the civ that's farther away. If the city in between is Barbarian, you need to kill or capture the city that is blocking your trade route (no open borders possible with Barbarian cities).

 

[Eunomiac]

If City A is an inland city with no coast or river access, can I connect it to City B (a coastal city on another island) by building a road from City A to a coast tile, or does it have to be connected by road to a coastal city?

I ask because I've been surprised by how my cities have unexpectedly hooked themselves up to my trade network -- I once built a city in the center square of a nine-tile square island, so it was separated from the coast by one tile in all directions (long story...). I didn't expect it to hook up to my trade network, but it did! I still have no idea how that worked ...

 

[Sonnybonds]

Problem solved. You must discover all coast tiles between the 2 cities.
now i have extra income for my civilization!!! thx for all the replies.

and Eunomiac: Yes you just build a road to the coast and its connected.

 

[Sartre311]

So if there are any unrevealed black tiles all around me on my isolated start then even if I have open borders with all of the civilizations as well as can trade resources with them, I will not get any foreign trade routes until I discover the territory between me and some other civilization across the ocean?

Thanks in advance