Basic questions about trade

[eluciv]

I feel stupid, but here goes:
How exactly does trade work?

When I build a Harbor and get the +50% from trade routes, what is that 50% being added to? What are the actual trade routes? Are they the deals you set up with other leaders? Or is this just calculated from your city's entire inventory of available gold-providing luxuries?

Also, Mercantilism and Free Market - the difference being an extra route and no foreign routes. What does this mean exactly? With Merc, can I not gain luxuries from another civ? What does +1 trade routes mean?

Please help me understand...

[Snotty]

WRT harbors, I assume it refers to the trade routes panel on the left hand side of the city screen. If you have two cities connected by a trade route (road, river or coast) then it should say (city name) +1 gold or more. I presume the gold is what gets increased by harbors. This will have more effect later on in the game when bigger cities provide bigger trade route gold bonuses to the cities connected to them.

I know the great lighthouse increases trade routes in coastal cities by 2, but that gives you 2 extra cities you can have trade routes with instead. Free trade works in the same way, giving you one extra route giving you a little bit of gold for each city. It is possible to have these routes only running between cities in your empire, but I think routes running to foreign cities are more lucrative.

Now would be a great time for someone to come along with the trade route formula

[Mergle]

It seems exploration is key here - you can only trade with foreign cities that you have discovered (explored, map trading, satellites). The cities then automatically generate trade routes for maximal income. However, internal trade routes are really pathetic (like 1commerce/turn) so it really pays to know where some foreign cities are. Foreign trade routes generate lots of commerce per turn, and the +50% bonus from a harbour is a big deal. [Of course, you also need the right tech, so you need (I think) astronomy for example to get off your own continent.] You can see trade routes on the left of your screen, 2nd box down (list of cities being traded with & how much commerce each route generates).

What this means is that if you've been stuck on your own little island and don't know where anyone is, mercantalism is far superior to free market. The extra (internal) trade route of free market will produce minimal income, and if you don't know any foreign cities you won't be trading with them anyway so no downside to merc. Foregin trade routes are big bucks, meaning once you've got several options for these, free market becomes the better option.

Mercantlism has no effect on you being able to trade resources, nor does it stop foreign cities benefiting from running a trade route to your cities.

[Enigma_Nova]

So, if you're the type of person to destroy and declare war on everyone around you, you're better off going Merchantilism

[eluciv]

Thanks guys.
I never took heed of the trade box...