Would it be possible, or desirable, to limit the cities to which a spy can travel to those that current techs determine.
eg.
I haven't as yet discovered navigation so ocean travel is not an option. However a few turns ago France became the chair of the 1st World Congress and therefore all the previously unknown civs are now known. A turn or two later I had established embassies with them all and I can now send my spy/diplomat to cities on the otherside of the map.
Another option is if we can't/don't want spies being limited is to have the most direct route from our capital to the other capital revealed to simulate the passage the spy takes.
This same curious behaviour is evident in early games with your 1st caravan/cargo ship.
You can be aware of a city that is close by, perhaps by a unit from it moving into view, but as yet not scouted out the path. Your trade unit however will just move through the fog from city to city.
eg.
I haven't as yet discovered navigation so ocean travel is not an option. However a few turns ago France became the chair of the 1st World Congress and therefore all the previously unknown civs are now known. A turn or two later I had established embassies with them all and I can now send my spy/diplomat to cities on the otherside of the map.
Another option is if we can't/don't want spies being limited is to have the most direct route from our capital to the other capital revealed to simulate the passage the spy takes.
This same curious behaviour is evident in early games with your 1st caravan/cargo ship.
You can be aware of a city that is close by, perhaps by a unit from it moving into view, but as yet not scouted out the path. Your trade unit however will just move through the fog from city to city.