I enjoy very early attempts at circumnavigation (immediately making three workboats, and sending the second and third out in opposite directions). At first I believed I was getting a possible bonus of some early international trade routes. However-- considering the details of DanF's thoughts you just pointed out to me-- I'm now worried I'm actually facilitating better international trade routes for my AI opponents, by establishing routes through MY territory that they wouldn't otherwise have.
I also like early coastal exploration in order to make contacts and establish lucrative foreign trade routes (the AI does it too while many human players seem to forget about it / neglect it), although I probably don't pursue it as aggressively as you. It should be synchronized with your research path (Sailing / Writing for open borders) and the onset of barb Galley danger.
To take my explanations and the discussion of the other thread linked by rolo further, I'd like to place an example here in Krikkitone's nice article to help players understand the trade network mechanics and their differences regarding resource trades and city trade routes.
The scenario I set up with WB (debug mode view): I'm Bismarck and have the Great Lighthouse in Berlin. My neighbors are Peter and Zara, we all have knowledge of Sailing.
First a picture showing
parts of my home plotgroup after toggling the trade groups display in the world view (probably one of the least often used functions in civ
):
You can see the gray patch consisting of all the tiles
within my borders which are linked to my capital via road, river, coast and ocean. Berlin has access to all resources on these tiles. But my home plotgroup which is relevant for establishing trade networks with my neighbors extends further -- right now all revealed land tiles adjacent to the rivers plus all revealed coast tiles outside of my borders are also part of it (enabled by Sailing, ocean tiles outside of a players culture require Astro).
Normal view of my explored tiles:
I have sent my Workboat to Peter's borders. The unowned coast tiles uncovered by the Workboat got added to my home plotgroup. Once I found the first coast tile within his culture, all tiles of Peter's gray patch (excluding his ocean tiles) joined my home plotgroup too.
The rule is that a tile is allowed to join a players home plotgroup if
- the tile is adjacent to the plotgroup
- the tile can be part of a trade network according to the player's tech level (tile has a road/railroad, is adjacent to river, is coast/ocean terrain and player knows Sailing/Astro)
- the tile is either revealed by this player or owned by anyone not hostile
- the tile is not blockaded by an enemy ship.
So now both Berlin's plot and Moscow's plot are part of my home plotgroup -- I have established a trade network connection
Berlin --> Moscow traderoute: in the scoreboard). This connection is
unidirectional, since Peter hasn't sent a Workboat yet, so his home plotgroup only comprises his gray patch and the adjacent tiles he has revealed, but not Berlin's tile. This means that we can both trade resources, but only I can benefit from a trade route Berlin --> Moscow.
I don't know where Zara's capital is, but I can trade resources with him too
traderoute: in the scoreboard). He sent his Workboat around my island and established another
unidirectional trade network connection
Aksum --> Berlin (Berlin's plot is in his home plotgroup but Aksum's plot isn't part of my home plotgroup).
Zara's view and capital with his trade route to Berlin:
Now the funny and interesting fact -- Aksum pops its borders into the third ring (100
) so that Peter's and Zara's gray patches touch. As there are no unowned AND unrevealed tiles left separating my home plotgroup from Zara's patch, all of Zara's patch tiles (\ocean) including Aksum's plot join my home plotgroup during the next recalculation. This turns the
unidirectional trade network connection
Aksum --> Berlin into the
bidirectional connection
Berlin <--> Aksum, so that Berlin can have a trade route to Aksum as well, in spite of me still being clueless where on earth this city might be located.
I've marked the tiles of ONE possible path through my home plotgroup from Berlin --> Aksum, going through Russian territory. It doesn't matter whether I have open borders with Peter or not, I just must not be at war with him.
~~~~~~~~~~
Thus aggressive early exploration by the human player does not give any major advantages to the AI as it doesn't enable trade routes for them, but they might show up demanding resources.