Capital Buildings
Each Region has a Capital City. Within that Capital, you can construct Capital Buildings. Capital Buildings aren’t really direct contributors to the economy at the Goods lines level in that they do not typically generate any Goods themselves. There are exceptions – the Scholars National Spirit allows you to build a Capital Building that produces Books, for example – but, in general, Capital Buildings represent more the overall infrastructure of a Region. That infrastructure takes some time to build up. Capital Buildings are built by the Capital, using the Production generated at the Capital, so there is a time component involved. Similarly, Capital Buildings can have requirements related to the Region – if you are in the Age of Rocketry and you want to build a Foreign Office Capital Building, it requires a Region Level of 3. A Region’s Region Level can be increased in a number of ways. Building a Town in the Region increases Region Level by one (as does levelling a Town already in the Region). Certain Capital Buildings, like the Food Stockpile in the Age of Stone or Aqueduct in Age of Iron, also increase Region Level.
Improvements
Improvements are somewhat the opposite of Capital Buildings, both mechanically and thematically. Where Capital Buildings represent general economic activity in a Region, Improvements represent specific industries or projects. Unlike Capital Buildings, Improvements are built in specific tiles, so they require available land within a Region and an expansion of borders over time if you want to support more of them. If you do not have enough space, you can be limited in the number of Improvements you can consider. Some Improvements also require certain types of terrain (you cannot build Fishing Boats in a Forest) which can further alter plans. (Note that an aspect of the tile need for Improvements is that they can be more vulnerable, as they cannot be worked if an enemy Army occupies the same space and they can also be razed.) Improvements also need workers (in most cases). Capital Buildings do not occupy population from the Region for their operation, but Improvements do. Hence, if something happens to reduce your population or if you construct more Improvements than a Region’s population can support, some of the Improvements can go idle. Where Capital Buildings are built with a Region’s Production, Improvements are placed with Improvement Points (in later Ages, with more advanced economies, Specialists replace IP for building certain Improvements). Unlike Production, IP is a shared national level resource and it accumulates. This creates very different possibilities for building Improvements compared to Capital Buildings. For example, you can focus IP from all sources on one Region if you want and, if you have saved IP for some time, you can immediately place multiple Improvements within one Region on the same turn. Economically, Improvements are the main “machinery” around Goods. There are exceptions, but generally Improvements either generate Goods directly (a Farm Improvement producing Wheat) or they convert Goods (a Mill Improvement taking in Wheat and producing Flour). Building and working Improvements is thus the primary way to obtain, alter, or improve Goods, and therefore defines a great deal of a Nation’s economic capability. Let’s walk through a simple Goods chain for an example. Say I am in Age of Rocketry, Age 8... Goods like Clay, Bricks, Marble, Logs, and Planks are important for development during earlier Ages. Later, Goods like Steel and Concrete drive strong development. Metal, in general, is a flexible Good and valuable from early stages of history. The Mining Technology in the Age of Bronze allows construction of Mine Improvements on hill terrain, which produce the Copper (or the more valuable Iron when you can find it). Mines and some of the related Improvements in the metal Goods line get better as technology progresses (the first Mines can be upgraded into more productive mines during the Renaissance, for example). In the Age of Revolution, the Steel Technology unlocks a new Improvement – the Steel Furnace. Once you have this technology, you’ll want to upgrade earlier furnaces (probably Blast Furnaces taking in metal to make Ingots) to Steel Furnaces, which can take in metal ore Goods and convert them to Steel. Steel is worth substantially more than Ingots (and a Steel Furnace has more capacity than the older Blast Furnace), but a more important consideration in most cases are the next steps in this Goods line – more modern metal-related Improvements require Steel to operate. So, if you want, you can just work Mines, feed the metal gathered there into Steel Furnaces, and add raw Production to a Region – just make it more capable of building. However, you can also build a deeper Goods line with additional Improvements that will allow you to get more from your Steel or get something other than Production. Once in the Age of Rocketry, for example, you might build a Machine Shop, and start feeding Steel there to make Power Tools (worth more Production). But, maybe you need more Wealth? If you do, you could instead build a Car Manufacturer and turn the Steel into Cars. Or, maybe you plan to get in some fights – in that case, you might want to build a Defense Manufacturer and use the Steel for Missiles.


Import and Export
Millennia has two general types of trade, Foreign Import and Domestic Export. Both are governed primarily by various Capital Buildings that determine capacity. For example, if you build a Shopping Center Capital Building in a Region, you gain three Foreign Import slots and be able to import up to three Goods into the Region. Foreign Import allows you to spend Wealth to acquire Goods from a world market. In all cases, you can import Trade Goods, which are worth Culture. If you have deployed an Envoy to the Region of another Nation, and are not at war with them, Goods produced in their Regions are added to the market and available for import. Foreign Import is a useful way to obtain a specific Good you have had difficulty finding or to convert excess Wealth into something more valuable. Domestic Export is similar, but it involves “trade” between your Regions, essentially sending Goods from one place to another.
Merchants
Merchants are a special Unit obtained using a Diplomacy Domain Power. They can be used in two different ways. When sent to a Region held by another Nation, they can be moved next to the Capital City of the Region and there deployed. Deployed Merchants generate Wealth every turn, based on the population of the Region where they are active. The second (and arguably more interesting) use for Merchants is to develop Vassals. When you found a new Region or capture a Region from an enemy, your new territory starts as a Vassal. Vassals can be converted into full Regions but Millennia does not assume that all Vassals eventually become Regions. Instead, since every Vassal contributes Resources each turn, in a lot of cases it is more effective to focus on building up a select set of Regions which are supported by a number of Vassals that remain Vassals.