[BTS] Trade routes & barbarians / other hostiles

[lindsay40k]

Someone remind me how it all works again.

If the line of coastal tiles between two landmasses has a barb or enemy unit at war, they can't connect via the tile it's on, right? And if you park a naval unit, does it automatically project a blockade radius against everyone it's at war with (meaning everybody, in the case of Privateers), or do you have to specifically order it to blockade?

What about roads, are they disabled if there's an enemy unit on them but the road has not been destroyed? Pretty sure I recall that camping on a mine without destroying it takes the resource offline...

Also, rivers - is there any way to kill connections along them other than by cutting through with closed borders?

Finally, airports - do they allow for a Berlin Airlift sort of trade network connection?

Thanks y'all

 

[InovA]

The coastal tiles must be controlled by a barb or enemy at war. As in the cultural border controlling the tile(s), units do not affect the connection. Same with roads, enemy units do not prevent roads from trading across it, or for strategic resources to come across them. And I thought camping on top of a resource prevented the resource from being used, but just tested it with barbs and a warring civ sitting on a Gold and Horse resource for 2 turns, but the road still connected them to my capital and allowed for horse-related units and gold's +100% production bonus on wonders to be available.

Airports do not override any trade route requirements. Oceanic, Coastal, or Road/River connections are required.

Rivers are a bit trickier. Just like roads, a controlled river/road by enemy cultural borders prevents trade across it, but for rivers you must control a tile on both sides of it in order to block trade.

Fairly certain that parked naval units do not automatically project a blockade. Couldn't find a way to test this, enemy privateers wouldn't stay still and great merchants' trade mission apparently works for full value through your own blockades, even though it's meant to be calculating based on the target city's trade route with your capital.

And of course, in order for a coastal connection to begin, you must reveal tiles all the way up to the cultural border of the partner civ's node and have open borders. (It is not required that you can see a coastal tile controlled by the partner civ, just the border up to it. As long as a straight line from any coastal city of yours can go from your vision to their culture controlled coastal tiles, a connection may begin. This also means if they place a coastal city on a coast you've previously seen, but you haven't seen this city or the culture border from it, the connection may begin.)

 

[elmurcis]

Side note - if AI explore (with workboat for example) coast to your empire and you get chance to trade resources but you don't explore, its possible that AI will get trade routes to you ("earn money" from OB) but you won't get trade routes to AI.
Also - if there are 2 islands separated by ocean but possible to get over with culture borders ("Ocean-bridge"), if one side can't get to other side with units (they don't have "Ocean-bridge"), it also can't get trade routes from other side. I had amazing games where I had even 6 AI in that situation (safe from military but with access to them). Net gain from OB over-sea trade routes was huge (was limited only by total number of cities all AI had but if every AI has 6 cities, human can gain 6 empires x6 cities x3 or 4 commerce from trade route- >100 commerce/turn with only 9 cities after Currency needed ) without increasing AI income

 

[s.bernbaum]

Someone remind me how it all works again.

If the line of coastal tiles between two landmasses has a barb or enemy unit at war, they can't connect via the tile it's on, right? And if you park a naval unit, does it automatically project a blockade radius against everyone it's at war with (meaning everybody, in the case of Privateers), or do you have to specifically order it to blockade?

What about roads, are they disabled if there's an enemy unit on them but the road has not been destroyed? Pretty sure I recall that camping on a mine without destroying it takes the resource offline...

Also, rivers - is there any way to kill connections along them other than by cutting through with closed borders?

Finally, airports - do they allow for a Berlin Airlift sort of trade network connection?

Thanks y'all

Mostly, your questions have been addressed by folks before me but regarding the part that I bolded above: If the empires in question have privateers then the coastal block to trade is moot. Since they have astronomy, the trade connection can occur across the open ocean not just along the coast. If you want to block it you have to place war ships along the coast and put them on blockade duty. The blockade may take more than one location of blockading ships because the blockade tiles need to cover the entire coast that connect to the enemy.

 

[lindsay40k]

Huh. I was convinced that barb ships interrupted coastal trade routes. Maybe I got it into my head by killing a barb galley and happening upon a naval trade node in between checking my trade routes.

Righto. Thanks, folks!

...one more thing. A, B and C are on separate continents. All have OB, all have Astronomy, all have full maps, all are sending a resource to each of the others, none are in Mercantilism. All resources are gifted individually as separate instances, rather than as my-silver-for-your-iron. A uses privateers to completely shut down B's coastline. Obviously, B loses all their international trade route revenues. But what about C's trade route revenues from B's cities, and all of the resource exports?