What other tech could affect this? I have animal husbandry, fishing & sailing. Sailing should permit trade along the coast, which is what is happening here.
I made extra tests, and that should be enough. With those techs, the horse resource should be connected to that city.
And indeed, it somewhat seems that it would work even without forts, with pure pasture(s).
When testing this with WB, I came to conclusion that it bugs somehow. I had several occasions where I didn't get the resource, and several occasions where I got it after modifying the "island" where I had the resource. I didn't see any pattern to how it sometimes decided that this resource now wont be connected, and now it is.
Yes, when I tested I:
- had the resource and the improvement (fort or the required improvement to use that resource) inside my culture borders
- had required techs
- had road on the tile
- had no ocean tiles between the city and the resource
Has someone made tests and found a pattern to those weird cases where the resource isn't connected?
One example I had: I had island of several tiles, and silver there, I WB'd a fort on that tile and a road, it was inside my cultural borders from a city on another island. it did not connect to that city. When I WB'd that silver island to remove some extra tiles from that island (made them water) suddenly the silver was connected to the city on that another island. When I remodified the water back to grassland (returned the island to its original form when the silver wasn't connected) it was still connected. Weird in my books. Its like the code that determines if resource is connected or not isn't checked every time. Pressing end of turn helped nothing, that wasn't the cause.
EDIT: Summa summarum, atleast with World Builder, the trade-route (connected or not connected) for resources in other islands ir highly irrational.