One of the things in Elemental we've been thinking hard on is how the economic system in the game should work. Elemental is, first and foremost, about building a civilization that happens to exist in a world filled with magic.
So when it comes to building things, we are trying to get away from the classic "N production units". There are, for instance, no factories in Elemental. We want players to really understand just how big of a deal it is for a civilization to be able to produce mounted warriors who have metal armor and metal weapons. It's not just knowing how to build such a unit, it's being able to put together the infrastructure to produce such a unit.
Players don't research types of units, they research technologies. Players then design their own units and those designs require certain resources. A basic soldier with a club is pretty easy. You take a guy, arm him with a big stick. A better soldier might involve same guy, armed with same stick but trained. Now he's much much better but it will obviously take longer to get that unit. It's not about production then, it's about time.
A still better soldier might be equipped a bronze sword instead of the stick. But that bronze sword didn't just come out of nowhere. The metal had to be mined and then forged and then delivered. Of course, the challenge from a game-design point of view is that you don't want players to be forced to micro-manage such things. It's supposed to be a strategy game, not an inventory management game. And so, you make that issue something for your civilization to deal with - not the player.
A given land tile may have a metal resource on it. The player builds a mine on it. That mine then produces N units of metal per turn. That metal then flows to the keep's inventory (in the city). When the keep's inventory gets filled, it then starts getting sent out to other cities (little caravans start appearing on the map delivering this stuff). All of this is automated but evidence of a growing civilization. Players can build warehouses to store more inventory of a resource. A player can also build an armory which produces weapons which flow again into the keep's inventory and then into warehouses if built and then out to the country side to other cities. Players can build roads to increase the speed in which these resources make it (and incidentally, these caravans only go out sporadically so the map isn't going to be full of these units running around and they're not true units, they'll be almost like decoration except when attacked).
So when I go to build a unit, the amount of time it takes to build that unit is going to be based on decisions I made -- what am I equipping him with. How much training am I giving him? And of course, since populations of "cities" range from 100 to 1 million or so, one of the resources units require are people. A village of 100 people obviously can't conjure up a legion no matter how much money and resources you have.
How will all this actually be implemented? That's where the open beta will come into play. Our development tools allow us to quickly implement many different concepts and UI's. that's where a lot of our work has gone into so that we can make changes like this. Players saw hints of this in Galactic Civilizations where we could make dramatic changes to the game based on player feedback but it's nothing compared to what we've built for Elemental.
So for instance, do players want to prioritize where these caravans go? How much control do players want of this kind of thing? Would it be more fun to actually have technology branches dedicated to having governors (not AI, just bonuses to supply) that "manage" this. These are some of the many things that players will be involved in.
The main thing I wanted to get across is that we are not going to have the traditional "N units of production". Players will be able to design their units, design how much training (a small squad of elite soldiers or a huge mob of untrained brutes or somewhere in between?), decide how well equipped you want them to be and so on. It's not about sending out a knight. There is no "knight" unit unless you choose to call a unit you designed that has a horse, a soldier who has been trained, plate mail, sword, helmet, etc. a knight when you save it. How long would this knight take to create? Possibly very little time at all if you have the plate mail, sword, helmet, and horse ready to go. Then it's just a matter of the training time. Otherwise, it could take quite a long time (the game will estimate the time based on arriving supplies).
Hopefully this gives you a glimpse at the strategic depth we want to provide players. The choices for players in how they want to play this game are endless.