This brings us to the subject of 'hammers,' and how they fit into the D&D system described thus far. What are they?
Yesterday, I suggested strongly that I wouldn't confuse the issue of creating buildings and features in your world using the Civilization IV (C4) money system. There might be a temptation to calculate the number of hammers as per the number of coins (the video game allows this calculation) and thus confuse the two things as though they are interchangeable. They are - in C4. If you want to retain the widest possible variety in D&D, however, they shouldn't be.
Hammers are the production measure of the game, whereby buildings and mobile units are built within the C4 game. In D&D, they would be a combination of manpower, resources and engineering skill ... and this is why coin does not equal hammers in the D&D system I propose. A building needs BOTH.
The coin, in order to pay the cost of building, in labor and materials ... and the hammers to determine how long it will take, given the resources of your community.
Any community, with enough time and money, no matter how small the community, should be able to build a stonehenge-like structure within its environs. The test isn't limited by the possibility ... it is limited by the willingness of a small community with 2 hammers available to it to spend 40 years on the project - assuming the master of the village doesn't die, causing the villagers to simply quit and possibly steal the object's components for other projects.
I would propose, then, that most of the structures in C4 could be duplicated in D&D. There's no limitation in terms of how many Hagia Sophia's could be built - except again, in D&D there are other relevant forces at work that do not exist in C4. The church, for example, not permitting such a structure, or vandals seeking to destroy it, or even the gods having a say. But that is for the DM to decide. The game is built on drama, and if someone wants to build something big, that should be both possible and a temptation for enemies.
The easiest way to limit this would be to invoke some rule that says the longer an object takes to build, the more resistance there is created against its construction. But let us leave off this digression, for the present, and get back to the details of hammers and how they work.
Because the number of hammers you have are necessarily measured against large numbers in the game (the Hagia Sophia requires 300 hammers), it isn't practical to measure such things in the binary number system proposed in previous posts. (300 1s in as a binary number is 2.03704 x 10 to the 90th power). Therefore, I suggest retaining the linear measure used in C4 ... so that an equivalent building to the Hagia Sophia would still cost 300 hammers. (as to the subject of the Hagia Sophia speeding up your workers, that's a problem we'll leave until we discuss workers).
So if we look again at the image I posted earlier today (and I'll post it again for convenience),
We can consider the number of hammers available in this area. Each forest here offers 1 hammer; the cows offer 2 hammers. The village itself offers 1 also. At a size of (1), and assuming the cows are not yet exploited, Bibracte offers a pool of 3 hammers for the construction of civic improvements within the town.
What civic improvements are available depends upon the tech level at which you think your world should operate. If Roman, then structures like castles, cathedrals and grocers are probably out of the question. On the other hand, forges, markets and harbors are perfectly in line. Realistically, you can ignore earth-like comparisons and just mix and match however you like, using or discarding technologies like cards in your deck. So long as the players have a list when they set out to make decisions, they'll be fine with your choices.
It won't do, however, to think of the construction of a single granary or forge as a "civic improvement" worthy of increasing your food supply or the number of your hammers (as such civic improvements allow in the game). It must be conceived that the whole village is reshaped by the 'granary' or 'forge' improvement, effectively redesigning its streets, constructing means to bring in the necessary materials, plus the difficulties of finding and encouraging the settlement of the necessary skilled workers. The cost in coin for such an adventure may be reasonable - it may even be paid by simply surrendering a certain amount of taxes, since most of the actual construction could be built by the new metalworker's guild forming in your town. (Perhaps I'm wrong - perhaps you could resort to C4 for the actual cost, recognizing that it, too, could not be considered a binary number). In any case, the 'hammer-time' would be long and arduous ... shortening the C4 turn rate to a year (I had previously supposed two years, but I am rethinking that also), it could still take 40 years for your 3 hammer village to grow an entire metalworker's guild.
Am I really suggesting that kind of time frame? Absolutely. The gentle reader may consider that anathema to the player's desires to have everything and right now, but if you adopt a wizard-speed option to the growth of your player's village, you're going to have trouble fitting that into the simultaneous growth (or static existence) of the rest of your world. Besides, imposing deeply distressing problems like excessive time periods encourages innovation. Remember, forests can be destroyed for hammers; mines can be founded; there's still the chance of some kind of cultural expansion; and the question must be addressed: can hammers be imported?
The answer must be YES ... but not by means of mere coin. Encouragement of a stable labor market based on skilled labor requires more than remuneration. What about conquest? What about slave labor? Just how desperate is your party to get that forge built in the next three years?
Really, each building needs an examination for what the actual D&D effects. Granaries couldn't operate as they do in C4 ... but they could preserve food against things that might happen in D&D but which wouldn't happen in C4: drought, for instance, or fire, or locusts, or the party destroying their own fields before the barbarians arrive. The hammers could simply be a measure of the time it would take to build a truly comprehensive storage system, capable of storing as much grain as all the fields produce (and getting grain from other areas who come to you to use up part of your granary).
So far, I haven't calculated how to use hammers to make military units or even settlers (though I'm close on the latter, and it is quite different from C4). I'm still working out workers. I will probably address that problem, and the problem of tile improvements, before even considering culture or - dare I say it - health.
Meanwhile, surely it must be evident by now that the "end game," if applying some of these ideas as I've been talking about, is anything but an END. The formula exists here to do more than give impetus to conquest, it defines precisely how conquest could benefit the players - and how they would account for every village and every city over which they eventually came into power. The possibilities are spectacular, since whole kingdoms could be regulated, to move hammers and people and grain from here to here, how much it would cost, and potentially how anger of the citizens could eventually cause a revolt (if you've played C4, you can guess some of the principles behind how that could happen).
I'm really onto something here. Next, I'll tackle workers and tile improvements.