There is a thing called trade. Which was the sole differrence between the rich and the poor lands, ever since someone invented currency. This is always included in games yet often feels either way too complex or too gimmicky, simply a reason to allow the box to say "Deep Trade System". Elemental has a base trade system, yet it could be made much more useful than allowing the nation a few extra bucks.

So what do we have? Caravans, and that is it... They give you money, and improve over time. And that's pretty much it. Not very deep or engaging.

I will explain some points on how to make a better yet hopefully not too complex trade system. This might not make it into box release, since the time to that is shortening, yet it could either be a mod, patch, or expansion. In any case here are some things worth considering:

Goods: Add another resource called goods that is used mostly for trade.

Gaining goods: Having one building produce goods will do it at full potential, another identical will do it at a lower rate. It should be a sloping root curve (I would start at 0.66^n). But another non-identical one would do it at the full rate, so that by having only one type of source for goods, you'd get less than if you have many sources. This partly simulates the supply and demand of real world trading, yet is not that messy to understand. If we want an even more advanced system, we can count all the sources connected to the same network, add away for monopoly etc. There should be ways to make yourself always get the most trade goods.

Transforming to goods: In a world that just went out the window, gold shouldn't matter the most. And you needn't only trade goods. But by including even more resources into trade it would get very bogged down very quick. Therefore you can transform other materials into goods at a rate that depends on how large your network(more on this later) is.

Transforming from goods: Goods could also buy resources from other lands, or allow for the purchase of materials you have in abundance at one place to be used somewhere else even better. What this means is that you can transform goods into other resources at a rate depending onnetwork size. Together with previous paragraph, goods can be used to transform gold into materials, or materials into gold, or into metal. All in all, a large trade means that you can exchange resources.

Trade Network: Size matters, it really does. This measures how well connected your nation is with itself and other nations.

Gaining network: The basic thing is to have two cities and connect them through a caravan. Connecting more cities with caravans would also increase your trade network. Caravans or road-building units that build roads to resources should also improve the network size. Building a trade cog and moving it into a neutral port would also establish a route for trade ovver water. Establishing trade treaties/pacts/aliances with other nations will give you both a percent of the other's network, if you are connected. A small treaty might give both 25% while a full trade union would give up to 90%.

Damaging the network: The routes of roads and waterways periodically send out small caravans or boats. While the caravans are outside of controlled territory they are exposed, see this. Succesfully attacking this gives you some gold, some trade goods, and a diplomacy penalty to the victim. It will also make the one who spawned the caravan, and teh one who owns the destination to lose trade goods. Bandits and animals might attack the caravans even in your territory if you haven't rooted them out. If they succeed, nothing happens, you just feel good for successfully protecting your trade network. If a caravan repeatedly gets stopped, the road it travels vanishes, and your network will shrink.

Protecting the Network: You can manually protect it with units, although this would get tedious after a certain size. There are two ways to do it. One way would be by hiring mercenaries that demand a portion of all the goods you get. They will in turn follow along the caravans. With a slider in the trade screen, you can decide how large a percentage you wnat for protection. Nr2: There should also be a possibilty for magic or some techs to help this, after all one option is no option.

So by adding two things (and a UI) we get a trade system that works and is neither unfair nor too exploitable. It might even be a strain if handled poorly. You see, large nations will get more goods, but will need more resources, while small nations will get less goods but also need less resources. The network can be equally large for small and big nations if you have a treaty inbetween you. It is also possible to starve nations if you all agree to break the treaties. This will give diplomacy extra weapons and make that more involving. It shouldn't be hard to code AI for it either.

Possible Technologies:

Convoys: The caravans are fewer, but carry more. This will however mean that the guards are more packed. Instead of facing three guards, you might face nine.

Mercenary Guilds: Mercenaries are more varied and generally better. You might have some archers and pikemen along with horses and swordsmen.

Technology diffusion: Every successful caravan has a 1% chance to discover a technology for every foreign nation connected to the network. Has a larger chance to succeed if you have convoys researched. (Since convoys are less frequent.)

A lot of technologies that generally improve the goods gain, goods tranform etc.

Do you think it would be fun and feasible?