more nerd than you can shake a stick at

[rone]

I did a little math today.  Take the Greyhawk gold piece, which is depicted in the Dungeons & Dragons v3.5 Player's Handbook as having the same size as a half-dollar piece (diameter of 30.61 mm), and is listed as weighing one fiftieth of a pound (9.012 g).  If you assume it is 100% gold, that gives a thickness of 0.639 mm, or less than half the thickness of a dime.  Not quite foil-thin, but i suspect that it would lead to a lot of crumpled coins, and trying to mint something that thin is probably not very practical.

My only comfort is that some nerd somewhere figured this out as soon as the book came out, and sent Wizards of the Coast a nastygram about it.

Comments

[ambyr.livejournal.com]

This seems to be a common problem in RPG settings. . .in my MUD, silver coins are 160 per pound. Even assuming they're smaller than dimes in diameter, that's pretty damn thin.

[mmcirvin.livejournal.com]

See, the gold is allied with mithril. I mean MOTHRIL. Public domain mothril!

[brokensymmetry.livejournal.com]

But don't the zero-point fluctuations of the magic field modify the 6s orbital so as to increase gold's tensile strength?

[urbeatle.livejournal.com]

you can't rely on mere chance. better compose a letter!

[haineux.livejournal.com]

My pal Dave Lyons made a Mac OS X program called MEASURE which is all about this kind of unit calculation geekery. Density, cost, elements 1-117, equations of area and volume, all included.

The only thing it doesn't do is calculate 6d20 vs saving throw.

Interestingly, a gold piece like you specify is worth darn close to $150 in gold in current US Dollars. Since I don't know when the book was written, it would be foolish to assume that they designed it that way, but.

http://www.unitsoftware.com

OK, I am done pimping, but what can I say? How else are you going to calculate the cost of coating the dome over the Boston capitol building in gold?

http://www.mass.gov/statehouse/dome.htm

[mskala.livejournal.com]

So the coins probably aren't 100% gold, even if the people who use them think they are. If it's 10K gold, it'll have a density of about 12 (pure gold would be about 19) so it'll be thicker for the same weight, and the alloying metals will make it harder also.

If the weight refers to the weight of actual gold not counting the other metals, then the coins could be even thicker. Probably not, because this weight is probably used for calculating encumberance and so it should be the actual weight; but real-life gold alloy coins are measured that way. A 1-oz Krugerrand actually weighs 12/11oz because it's 22K gold; you get 1oz of gold and 1/11oz of copper.

Note that weight used for encumberance in RPGs may also include a discount or penalty for some objects being more convenient to carry than others. If that's the case, though, the rules should say so.

[hwrnmnbsol.livejournal.com]

A similar argument was made to me in one of my games. Here, as verbatim as I am able to recall it, is my reply:

"Yes, Darin, but what you fail to take into account is the Greyhawk minting process. Greyhawk, as you will recall, is a city-state founded upon commerce. Moving large amounts of currency rapidly has been a concern of the ruling merchant class as long as Greyhawk has existed. Accordingly, given the magical nature of this world, a solution has been found.

"The Greyhawk Mint is a sturdy fortress-like structure midway along Barter Street. Here, behind six-foot-thick walls laced with phase spider webbing to prevent ethereal intrusion, magma paraelementals pour molten gold from alembics into the casting-plates. As the eagle is impressed upon each coin, an incantation is uttered by the batteries of mages employed by the mint. When the metal cools, each coin is placed upon a scale, and is found to weigh only 1/4 of what it should based on metal content.

"This weight has not gone away; if it had, this would represent a magical effect on the coins that could be dispelled. Instead the weight has been transferred. In the deepest bowels of the mint is a ball of silken thread too large to be swallowed by a purple worm; five demons of considerable strength struggle to hold the ball aloft, because its weight would crush stone. All the excess weight from Greyhawk coinage has been shunted into this silken ball, and it will remain there until the demons are scattered and the thread unrolled. At that time all Greyhawk gold pieces will regain their weight, and merchants' pouches will rip their belts loose, and all their pants will fall down.

"And that, Darin, is why gold pieces weigh so little. Now suck my pole, and then get me another Mountain Dew."

Actually,

[vardissakheli.livejournal.com]

weren't US gold dollars about that thickness? Of course, they were also close in diameter to dimes and so provided less leverage for bending.

[nyar.livejournal.com]

What in the name of Random D&D Campaign Deity prompted you to do this!?