Community Wealth and Population

[the Lorax]

Which goes to show that you cannot use the rule strictly.
I recall that the example given in the DM's guide is a bit ubsurd, something about a village of 40 having 30 long swords on hand or something like that. The rule is just a measuring stick that doesn't work well for common mundane items. If someone is in a metropolis they should be able to find whatever common mundane items that they could desire. If you have players who are looking to buy 7 billion chickens then you may be dealing with players who are silly enough that they could care less about any illusion of an economic system being in place.

 

[reanjr]

So in a village with 400 or so habitants, there is a family of wizards. The head family member is level 17, the second is level 14. The children are levels 1-4. Many people goto the village to buy, identify, sell stuff, whats the wealth then?

I see two options for this type of scenario (which by the way is an impossible scenario if you use the demographics in the DMG, so it's understandable that it's not really covered by the rules).

Option 1: The wizard family probably has to deal with merchant's outside of their own town for most of its needs. Any kind of service or good the local population can provide it, the family can do without (food, buildings etc. can all be handled through magic). In this case, I'd treat the wizard family as its own economic entity, not making a big impact on the community, nor being impacted by it. The only affect might be to have a particularly wealthy class (maybe only a single family) of traders who support the wizard family by travelling to and fro nearby cities.

Option 2: The entire economy of the town is supported by the wizard family. Everyone in the town pretty much works to sustain the wizards. There are a large number of fine craftsmen in the town, but their economy as far as the PCs are concerned is not much greater than normal, since most of their time is spent in leisure or in working for the wizards. Most staple goods are imported and might cost up to twice their normal cost. There are a large number of traders living in town to support this large amount of import, but they would not be particularly wealthy in this model.

 

[dcollins]

In the DMG, there is a formula for determining how much wealth a town has, in terms of how much it can sell and buy before exhausting it's gold.

I do use this for a number of details. The population a gold piece limit of the priciest magic item I use as written. Previously, I made up specific magic-item crafting NPCs, with specfic feats, spells known, etc., and required PCs to seek them out and commission items that they could satisfy prerequisites for. That was nice for flavor (and colorful characters), but frankly took up too much time, so now I generally assume any standard DMG items under that GP limit are available on the market.

I use the figure for "ready cash" as well, in case PCs starting selling items or somehow the community gets plundered.

The one piece that I don't use is the "or the total value of any given item of equipment" clause, because as said above, it wasn't fully thought out. The issue has never come up in any of my campaigns. If it did, my first guess at a fix would be to qualify it by category (that total value of livestock, trade goods, arms and armor, miscellaneous magic, etc.)

 

[reanjr]

LOL.

Would you mind mentioning how you handle economy in your game, basically the buying and selling of items and equipment? How do you determine how much of a particular item is "in stock" and how much a PC can sell to a particular trader before expending that trader's cash reserve?

I usually play it by ear. In a metropolis, any reasonable amount of mundane equipment is generally available (if you want to buy 1,000 longswords, you can, but you would have to find several different merchants). But for unusual items (spiked chains for instance) they are usually in limited quantity, though almost always available for list price and there are several people who can craft such an item. Putting 1,000 spiked chains on order probably wouldn't take an awfully long time, but you would be spending a bit more than normal to expedite the process (they've got other - regular - customers to deal with).

Once you start dealing with larger numbers than about 1/100th the population, you start seeing a huge amount of inflation. Even if the craftsmen can easily keep up with demand, they are likely to take advantage of the situation and charge accordingly. Perhaps as a rule of thumb do cost multiplier = (#Items * 100 / Pop.) ^ (1.5) for numbers greater than 1/100th the population. To purchase 10,000 swords from a population of the same number could then be done at an astronomical cost. Basically, you have to pay for the entire economy of the city as everyone temporarily drops their normal jobs to learn to help make swords and do so. The cost would be 475 gp per sword in a city of 100,000, which seems reasonable to me. Part of this cost can be assumed to be paying off officials to allow such a great undertaking.

Generally, I would allow the selling of items at normal 50% cost to an average of 10 per buyer. But traders in similar goods are often members of guilds and word will spread if the PCs start selling to multiple merchants. Once you start selling beyond about 10% of 1/100th buy limit, you will start to see deflation on that product as the economy becomes saturated with it. Rule of thumb sell price multipler = (#Items * 1,500 / Pop.) ^ (-1.5). Selling 1,000 longswords to a city of 100,000 (the natural buy limit if you follow my previous advice and ten times the sell limit), you'd be selling for about 4 to the gp. A bit low, but the numbers for the formula are pretty, and it's reasonable enough. I mean, what are all these merchant's going to do with all this excess stock anyway? (The 1,500 in the equation should more accurately be about 1575, but 1500 is a prettier number).

If you want better accuracy, you can, of course, use the limit of an infinite sum, but I think that method would be a bit too complicated for the average DM. It would better represent the fact that the cost is constantly changing as you buy or sell more and more.

As far as an influx of gold affecting the overall economy, I prefer to deal primarily with particular industries. The smithing industry (including those who mine iron ore, and also maybe coopers or masons, for instance) would be affected by the purchase and sale of swords, while the tanning industry (including those who raise cows and/or hunt) might be affected by the purchase and sale of leather armor.

So to summarize

Buying:
Natural buy limit (the number the PCs can buy before inflation kicks in): Population / 100
Inflation past buy limit = (#Items * 100 / Pop.) ^ (1.5)

Selling:
Natural sell limit (the number the PCs can sell before deflation kicks in): Population / 1,000
Deflation past sell limit = (#Items * 1,500 / Pop.) ^ (-1.5)