World-Building Nuance — Coinage of the Realm

In the far, far olden days of 1st edition (“Basic”) Dungeons and Dragons, 10 gold pieces weighed a pound. It was simple. It involved a handy round-off from troy ounces (which are 12 to the pound.) It was almost everything we needed to know. Except for one thing.

The central question of value was as easy as weight. D&D came with price lists for swords and food and armor and what-not. Budgeting was everything. Spending the treasure was the game.

A 1-oz gold coin is — well — how big? 

The resources to research this nuanced, side-bar factoid were hard to come by. It meant going to the library and hoping to find enough detail in the paper encyclopedia to work it out. It was 1974 and the “Internet” was still RFC 675, a proof of concept for connecting computers. You couldn’t Google up the size of a coin.

(The World Wide Web dates from 1989. By then, I’d switched to the Hero Game System and some of the D&D nuances were behind me. Except for the question of “how big is that pile of treasure?” Fantasy Hero had it’s own price lists. My world-building had my own unique price lists. Value is easy, weight was easy. Other physical constraints on treasure piles were still kind of vague.)

We did things like weigh a bag of 50¢ pieces to try to extrapolate from there. A US nickel is exactly 5.0 grams, and five rolls of 100 nickels is half a kilo, 1.1 pounds. So, a D&D gold piece was the same weight as 6 nickels (Troy ounces, remember?) Interesting, but, not an answer to how big?

When you looted a dungeon and found a treasure room with 1,000 gold, how big were the bags? The rules told us it was 100 pounds of metal, a difficult thing to move. How many bags? How big were the bags?

World building has changed a lot.

I adopted the size of a nickel without any good reason for this choice. So, a pile of 1,000 gold was the size of a pile of 1,000 nickels — 500 rolls of 20 coins. A space about .5m×.5m (18″×18″) piled twenty deep. (This isn’t a great approximation, but it worked for game purposes; it was close enough to reality to avoid lengthy arguments from players. A better approximation requires working out an “angle of repose” for coins to see how the pile spreads out.)

Today, for funsies, I looked up coin sizes and weights. Air-Tites has everything you could ever want to know about coinage and coin sizes.

A US 50¢ piece and a 1 oz. gold coin are roughly the same size. (Close enough for #EpicFantasy. Remember, clipping the edges of coins is a time-honored practice when coins were precious metal. Reeding on the edge of a dime or quarter prevented clipping.) They’re about 30mm in diameter. Not the 20mm I used all those years ago.

Throughout The Forge, the Mage is so poor, money isn’t actually a thing. Looking down the road, in later books the question of money and budgets is going to become a thing.

The game-design price-list details of what a silver shilling can buy has no dramatic value. However, the consequences of having money, but never having enough money, becomes part of the drama. What’s important is to have a respectable amount of money and need to spend more and specific things that deplete the budget. 


As a nod to fashion, I need to keep the Mage’s purse to a sensible size. A few books. A few coins. A pencil.

 © F. L. Stevens 2019