Converting TTRPG Currencies: A Nerdy Math Problem

I thought some people might enjoy this little math story, particularly because of the funny ending. I’m running old Basic D&D adventures (B2 and B5) using Mongoose Legend rules. Now Legend is one of the d100 family of games and they collectively have always been known for having a more realistic economy than D&D. Prices in D&D are based of the utility of the item to adventurers and not how easy the object is to make or how hard the materials to make are to get. Runequest and its descendants have always tried to consider these things when setting in-game prices.

So, the problem is, “How should I change the treasure awarded in the old modules to match the Legend economics?”

I’m a very analytic person, so I jumped right in. First, let’s look at the currencies. Basic D&D uses the Gold Piece as the standard, with 10 CP equal to 1 SP and 10 SP equal to 1 GP. While Legend uses the SP as the standard with 10 CP equal to 1 SP and 20 SP equal to 1 GP. To relate these currencies, I build a table of common items that have prices in both games, and I get this:

Basic D&D price, followed by Legend.

• Crossbow , 30, 350
• Longbow, 40, 200
• Short Sword, 7, 100
• Backpack, 5, 5
• Sack, Small, 1, 0.2
• Lantern, 10, 10
• Chain Mail Armor, 40, 400
• Plate Mail, 60, 1200
• Thieves Tools, 25, 75
• Dagger, 3, 30
• Rope, 5, 10

Famously, Runequest charges a lot more for armor and metal weapons. That was the stuff of the wealthy elites, while other items have the same or similar cost—just in SP instead of GP.

Making a scatterplot of this data, and fitting a linear regression line (forced through 0,0), I get:

My R^2 is not bad. The linear model explains 78% of the overall variation. That seems good. All I need to do to convert treasure form the old modules to my game is multiple the number of GPs by 12.8 and convert them to silver pieces.

But wait. I want the rewards of the adventures to be richer than what the old Basic rules would give. I want the place of adventure to be so rewarding that adventures will come, not just to make a living, but to become wealthy. How could I do this? I could give out two thirds more monetary treasure than the old module states.

If I do increase the rewards, then all I have to do is keep the treasure exactly how it is listed. The low value coins will be a little off, but they are just filler. When the monsters have gold, just give it as gold.

(Artwork copyright Daniel F. Walthall, used with permission.)

Lets talk about Niven’s Ringworld

 

TL;DR. Before we can start understanding my Dyson sphere conjecture, we need to understand Nivin’s Ringworld. There are technical details provided for the ring, many of which make sense with today’s knowledge, others require materials that we could not explain today, and some minor details are left unexplained. But in the end, things like Dyson spheres and ringworlds are more about the enigma they represent to the protagonist than they are about the actual structure.

This is Part 2 of my series on Dyson spheres. Part 1 is here. 

Larry Nivin wrote a series of science fiction novels set in his Known Space setting. The ringworld was a giant, ancient structure with a habitable surface area about three million times that of the Earth. To put that in perspective, the Star Wars Visual Encyclopedia states that the Star Wars universe has a total of 3.2 million worlds. So, Nivin’s ringworld has a habitable area on the order of that of the Star Wars universe.

Image curtesy: Eric M. Jones, CC BY-SA 4.0, via Wikimedia Commons.

What is it? Pretty much what it says on the tin. The ringworld is a ring of an unobtainium material called scrith which encircles a star and by rotating at just the correct speed anyone standing on the inner surface of the ring will experience a centrifugal force about equal to earth’s gravity. This is a Sci Fi megastructure of the first order, but there are a number of technical details worth considering.

Orbital Instability. If perfectly balanced and in a featureless universe, the ringworld will spin around its star without a problem forever. Unfortunately, we are not in a featureless universe and eventually something will give the ring a little nudge. Once this happens, the gravitational attraction of the star will start to pull the ring inward, and the entire system will collapse. This issue is easily corrected by having a system of active thrusters which can provide small correcting forces to keep the ring in place.

Day and Night. Constant sunlight will heat the surface of the ring making it uninhabitable. To counter this, an inner ring is placed between the star and the ringworld with shadow squares blocking the sun and creating artificial night. The squares are wired together, presumably with scrith, and rotate in a way that creates Earth-like day and night.

Retaining Atmosphere. Any gases placed on the inner surface of the ring will fall off the edge and flow outward into space. This is prevented by building up walls taller than the atmosphere on either edge. The rim-walls on Nivin’s ringworld are 1,000 miles tall. The good news is that on Earth our atmosphere has the bulk of its mass within 11 kilometers of the surface. Unfortunately, traces of the atmosphere extend much higher than that so over time, the atmosphere would bleed off.

Atmospheric Inertia. Additionally, the air will feel inertial which should be realized as a strong wind blowing in the opposite direction of rotation. I’ll be honest here, I don’t recall how Niven delt with this, and I couldn’t find an answer. But, by the time you can build a ringworld, this should be easy enough to fix. Simply having thin baffles between the rim-walls would likely go a long ways, but I’ll leave the specifics as an exercise for interested readers.

Physical Properties of Scrith. It is only a math/physics problem to calculate the strength needed for the ringworld to not fly as it rotates. And someone has done this and the conclusion is that the hull-metal scrith would need to bind together with roughly the strength of the strong nuclear force. Of course, there is nothing known to us that can even begin to do this, so we simple except the existence of this material and get on with the story.

 

Role of the Ringworld

What is the point of Niven’s ringworld? In his stories it is an enigma. Characters discover its existence and are compelled to explore it and its mysteries. It is a physical manifestation that current human existence does not know all that can and will be. There are things out there that we have yet to learn. There are goals out there that we have yet to achieve.

I would argue that the existence of the ringworld allows us to imagine a protagonist who is in a world which is technically advanced relative to that of the reader, but which still has mysteries or enigmas.

In Star Maker (1937), Olaf Stapledon explores his view of the ever-increasing complexity of civilization and the nature of intelligence. I don’t agree with his conclusion, but man do I respect his presentation. Along the way, Stapledon introduces us to civilizations that can easily build things such as a ringworld. In Niven’s stories the ring is simply an enigma to be investigated. A place on which an adventure can unfold.

In my next installment on Dyson spheres, I will introduce my idea for a sphere. Like Niven’s ringworld, it will have strengths and weaknesses. But it will allow us to imagine stories—modern stories—that are centered around the nature of humanity and how much there is still left to learn.

 

B5 Horror on the Hill Monastery Map

 

The map of the monastery that comes with the classic TSR module B5, Horror on the Hill just doesn't work for me, so I redrew it. The version above is for the players as they enter the monastery and the one below is for the DM. Feel free to use them if you would like.

Is Biological Determinism the Root of Racism in D&D?

 

TL;DR: Dungeons and Dragons builds biological determinism into its rules, and biological determinism is a key element of raciest thought. Not all TTRPGs do this, but D&D does so as if it were the natural and only way to model a person.

 

Game mechanics define a world.

Whenever we engage in a tabletop roleplaying game, we are making certain assumptions about how the world works. Those are the things that we don’t need to say (or write in the rules) because everyone understands them—at least, close enough.

DM: “All of your characters have met at the tavern.”

Assumption: Taverns exist. People can meet at taverns. Etc. etc. etc.

When we write the rules to a game, that is when we write the mechanics by which event happen in our fictional world, we are creating the framework in which a group of people are going to collaboratively tell a story. The mechanics create both implicit and explicit statements about how the world of this joint story telling works.

 

Biological determinism

Biological determinism is the idea that most behavioral and physical traits of a person are “inherent” to that person, or that they arise from a person’s genetics which they inherited from their parents. Hardcore biological determinists believe that a person who engages in criminal behavior, for example, would engage in criminal behavior no matter how they were raised or what opportunities they were given. These biological determinists believe human social problems stem from human biology and not from the human environment.

I know people who argue that human intelligence is mainly (actually, in the case of some [REDACTED] poorly-informed people I know, exclusively) the result of their genetic profile. They have argued, in public, that educating those people with this “genetic inferiority” is a waste, as (they incorrectly assert) “those people can’t learn.”

Likewise, biological determinists frequently argue that successful people are successful because of who they are biologically, not because of the role of their environment. Unfortunately for the biological determinists, real world humanity went through a genetic bottle neck a few tens of thousands of years ago, and we have almost no genetic diversity, at least not compared to “typical” mammalian species and every time someone carefully looks for a biological basis for major human behaviors or abilities, they fail to find it.

The lack of human biological diversity is easy to see. Take a simple example, when I was young, I could run a mile in five minutes. I was not in any way considered fast or fit, but when I was jogging daily, I got to a point where I could run around a five-minute mile. The world’s record, set over a quarter of a century ago, is roughly 33% faster than that. Not twice as fast, that would require a two-and-a-half-minute mile and certainly not five times as fast, requiring a one-minute mile. When we look at something easily measured, there is about a 33% difference between an average guy and the world’s best.  And that’s the total variation, without even looking at the question of genetics versus environment.

Every time we look carefully, we see that biological determinism plays a weak role in setting the human condition. But a lot of people believe in it.

 

Biologically Deterministic Game Mechanics

Which brings us to D&D. Building characters is, inherently, a task of modeling the differences between people. How is my character different from yours? If you are old enough to have played Steve Jackson’s game Car Wars, you may recall that all drivers and gunners had three hit points. That game was about the differences between cars and the differences between humans was insignificant compared to that of cars, so they just called all people all the same.

When you look at character generation in those games derived from Greg Stafford and Steve Perrin’s original Runequest, the d100 games (Mythras, Call of Cthuhlu and modern Runequest being three obvious examples), you will see that characters are differentiated by their culture and their occupation (except C of C doesn’t worry about culture).

But not race.

Games derived from early D&D, like D&D 5e and Pathfinder, model the differences between characters as coming from their race and their profession. Race, not culture! An orc raised by humans will be an orc. In early versions, that orc would even still be evil—just like mom and dad. But even now their physique is inherent to them; they will be big, strong, and (until recently) dim witted.

This sits very well with those people who believe in biological determinism in humans. They will argue that humans have inherent cultures and that the cultures reflect the inherent underlying biology of the people in them. Orcs become a “stand in” for some human culture they view as “orc like” and elves are a stand in for some “elf like” group.

The d100 games, Runequest, have never had this idea of race and have never been as popular in areas where most people are biological determinists. (I’m basing this statement of my own lived-experience in the rural American Midwest and South, and I could be wrong about that—but this is my blog and I’m going to say it and if you think I’m wrong, you will need to show me some data.)

But d100 games do have species…

Most d100 games do have the idea of species. But it was never a common element of play that characters would be from a group of different species. If you are playing Elf Quest, you play elves, if you are playing Runequest, you play humans. Classic Fantasy being an obvious exception, but there it is purposefully attempting to capture the mechanics of OSR games.

I will add here that my game, Rubble and Ruin, very purposefully has biological determinism in the form of intentional genetic engineering. My goal was to show a world where people actually had substantial levels of genetic alterations which were purposefully induced. Basically, the biological determinists got to create the world they wanted to be true, and things went bad as a result.

The idea in d100 games is that there are biological elements that differentiate members of different species, and then their different cultures get layered on top of that. In the real world we only have humans, so we can differentiate them with their cultures, but in our imagined worlds we can imagine different species like elves and orcs coexisting with humans.

“Yeah, hey, that’s what we’re doing in D&D too,” one might say.

But we’re not. The existence of half-elves and half-orcs and half-demons and half-dragons and elemental bloodlines and all the other things is an implicit statement that all these different beings are elements of humanity. The differences between an orc and a “human” are cultural.

 

What do I want from you?

First, I hope that readers will think about how the mechanics of the games you play reflect assumptions about how the imaginary world being created works. I believe it is worthwhile to consider worlds with biological determinism, heck, I purposefully wrote a game with it. I want players to think about what it would be like to live in worlds where these beliefs were actually true. I would like all players at the table to be aware that the game they are playing assumes (or does not assume) biological determinism, and why. In Rubble and Ruin, it exists because pre-war billionaires employed genetic engineers to create it—and this is the world they left behind. In my understanding of Tolkien’s world, it is because there is a magical “absolute evil” which can corrupt bloodlines and this is the world created by that power.

Second, I would love to see people look into the actual science regarding their beliefs. Don’t take my world on the failure to find any profound basis for biological determinism. Start reading peer-reviewed literature on the topic. A reasonable open-access place to start is here.