Greetings... (warning, strange english ahead...) 

A realm/empire/kingdom is a growing, pulsating, interacting system. Currently, for my taste, Elementals lacks somewhat in this area.

I focus now on economics and a little strategic land-control.

Caravan-System

Each believable realm has to have a transport infrastructure. Momentarily this (roads) is been build by caravans. So be it (but I would like a Sapper-Unit for tactical combat). 

My grip of Caravans – and with it, the economic of my realm – would be somewhat different.

First of all we may need more of them, read on und you will understand why.

Second, the Caravanserai - A necessary building because caravans will be more important in my suggestion!

This improvement provides (aka hires) a strong or upgradable Guard which escorts every Caravan from this city.Very useful if you want a route through infested forests - but mind the upkeep of these mercenaries.

So, on to the system…

There are global resources – this stays so – but Caravans are now used to connect our city to the global resources.

• Until a city has road (made by a caravan) each production costs 50% more.
• Until a city has road, Units that need special Resources (like Metal, Crystal, Horses) can only be build if the City has access to it (it is in her vicinity)  

After you establish the road it’s considered “active” as long as a caravan use it (for trading). 

Once all caravans to a given city are destroyed – ether through monster or war – the following happens:

• Production costs +10% more global Gold and Materials per round, till it reaches the cap of +50%. (Alternatively we could model this with increased build-time)   
• You only have this city’s own resources at hand to produces and build units.
• Your Merchant has only a reduced assortment of goods (the basic ones)  
• If there isn’t enough food the settlement will lose population – but no units! (A little contrary to the Keeps below) 

So a kind of economic crippling war (guerrilla war, civil war) is possible.

What other effects do caravans have?

1. Every Time one arrives there is a little chance that a unique trader screen appears. He sells maps for special Quest Location, unique Items, etc. The calculation of frequency and potency needs to consider the levels of the connected cities.                
2. An active caravan between cites generates 2 Gold or 1 Food per turn.
3. An active caravan between cities generates 1 Immigrant per turn - if one city has reached its housing-limit and the other not.  

By the way: Roads

Stardock could let us design the caravan-route and thru that the road, so we can circumvent the big, bad wolfs… äh woods. But the actual creation must then cost a little. Suggestion:

Number of tiles actually used for the road minus the minimal tiles between the cities cost one gold and one material (alternatively one Stone) per tile.

Was this all? No. I will incorporate another important idea.

The Keep (upgradable)

This Building can be constructed by a Pioneer, somewhere in the countryside, x tiles away from your city. It must be connected by a caravan (road) to the global Net to function properly. Its effect and uses are:

• Generates a small non-expanding Zone of Control for Resource-Gathering.
• Grand a protection bonus to stationed units (but space is limited)
• Hampers potentially enemy units (see upgrades)

Upgrades

• Bigger Building: More Units fit inside
• Storage & Well: Units don’t starve for a long time in a
• Better Defence: Higher protection bonus   (As long as there is no better solution in tactical combat)
• Force projection: Enemy units move slower in the ZoC of the Keep, or other more magical Effects, like Aura of Sickness, Bolt throwers,…

 Obvious Benefits:

• Gets far-away resources à Less city spawn
• Better/bigger road net à faster travelling for non-magically armies
• But also a more organic or medieval look of your realm.

Dangers / Disadvantage

• Caravans to keeps generate no other income.
• If the route is capped (war, monster) the units begin to starve --> they lose hit points if the keep has no storage/well upgrade. In case of a siege going on, stepping outside the door (to hunt) may be not so good an option.

Thanx

Aygis