The Perfect OSR Sandbox?

I’m going total fanboy here and describing the old-school sandbox campaign I put together using a handful of inexpensive, commercially available products and a little creativity. I have no commercial relationship with the vendors, but I do follow Raging Swan Press of Patreon—because I really like their work.

I am currently running this setting using Mongoose Legend rules, I hope to run it someday with Mythras, but it nothing here is setting specific. Raging Swan has versions of Citadel on the Wilderlands in 5e, and OSR right now but you can easily port to anything else.  

The Set Up

We will take a modern OSR setting that is designed to accommodate two old and classic Basic D&D adventures, then add to it my personal favorite classic AD&D adventure. Since the Basic D&D adventures each have several wilderness encounters before the players get to the place of adventure, I have mapped them onto the setting map—so you don’t have to. Of course, as a GM you’re free to change it however you want.

Citadel on the Wilderlands, by Raging Swan Press, allows us to run that absolutely fantastic low-level, OSR campaign that I've always wanted to play, but never did. We are going to mix together with it, U1 The Sinister Secret of Saltmarsh, B2 Keep on the Borderlands, and B5 Horror on the Hill.

 

Sources

Citadel on the Wilderlands: Raging Swan Press or Drivethrurpg

Colorized maps: Raging Swan Press (And, yes I colorized these maps)

Thornhill: Raging Swan Press

There is also another adventure based here for 5th level characters, (OSR, P1, 5e)

U1 The Sinister Secret of Saltmarsh: Drivethrurpg

B2 Keep on the Borderlands: Drivethrurpg 

B5 Horror on the Hill: Drivethrurpg

 

The Map

I've taken the Skeleton Coast map and marked on it how I have placed the various numbered encounters from the adventures. (For most browsers, right click to download).

U1 The Sinister Secret of Saltmarsh fits easily enough on to the island of Solonor. It has one permanent location, an old, haunted house. Instead of the old house being on a coastal road, it is now abandoned above a cliff face, a little less than a mile outside of Bleakhaven. The only change needed is that the four wondering goblins are hiding out there as they look for things to steal from the humans--or some such—instead of travelling from one place to another. And the smuggler's ship Sea Ghost is a Picaroon ship.

The other two adventures on the mainland. B2 Keep on the Borderlands is centered on the Caves of Chaos, which in this version become the Ebbur Caves. Likewise, the Ruined Monastery from B5 Horror on the Hill becomes the Monastery of Ineffable Evil.

The overland adventure portions of both modules are mapped onto the Skeleton Coast map. Solid red lines are good trails. Characters can travel three hexes per hour on good trails. Dashed red lines are poor trails. Characters can only travel two hexes per hour on these. Characters take one hour per hex when off trails and must make some kind of Navigation roll or become disoriented.

Circled purple numbers correspond to B2 Keep on the Borderlands outdoor encounters.

Red Numbers correspond to B5 Horror on the Hill outdoor encounters. The Monastery of Ineffable Evil is the ruined monastery from B5 Horror on the Hill, but until Wild Swan Press releases their own monastery map, I will be using mine, and you can too. It can be found here.

 

Purples lines mark the underground locations of the Ebbur caves. Yellow letters correspond to the Cave Entrances in B2 Keep on the Borderlands.

The Letter sites are keyed. Letters in red on the Key correspond to the Citadel on the Wilderlands group name, while the three in purple don't have a Citadel equivalent (that I could find).

 

There are great, separate maps for each of the Key caves / mini-dungeons by  Dyson Logos. They can be found here.

Dyson’s Dodecahedron: First Six 

Dyson’s Dodecahedron: remainder 

 

Lastly, I moved the village of Thornhill from Ashlar to Fenmire. This gives the players a safe-ish place away from the island and I think it works well here. And the GM could add a fourth, modern adventure from Raging Swan, set there when the players level up enough.

As always, questions and comments are appreciated.

Firearms in Rubble and Ruin

 (Banner art credit to Jeshields*)

One of my goals with Rubble and Ruin is to create a game that uses elements of our real world in a fantastic or fantasy way. So, we don’t have spells and magic weapons. But we do have +1 swords. It is just that a +1 sword is made with superior material and therefore gives its wielder an advantage in combat. Likewise, we don’t have wizards casting spells, but we do have dangerous and hard to find weapons, the most common of which are firearms.

When I was a kid, the word “gun” referred to a piece of military ordinance, what many people today would call a cannon or artillery. A handgun or a longarm or a rifle or a pistol or a revolver would all be called firearms. I’ll stick to that usage here. (As an aside, there are people who go ballistic when you call a pistol a gun—but most of these people don’t understand the fluid nature of the English language—and I don’t really care about their opinions, but I feel it is worthwhile for people to become familiar with the technical terms for the common items in our world.)

I have written another post about old-school gaming and firearms. It can be found here. 

Background

Guns kill. Back in the 1990’s I used to hang out with a firearms examiner for the Illinois State Police. And one of the things I learned from him was that most homicides were the result of a single shot from a .22 caliber weapon. In other words, a single shot from a small pistol or rifle is enough to kill a person. But that doesn’t mean that a single shot typically will. The shot has to hit and damage a part of the targets body that is essential for life. Most shots, fired in anger, miss their target. And many that do hit, do not create a lethal wound.

Armor is Binary. Technically, we would say there is a sigmoidal response for bullets interacting with armor. This is a really fancy way of saying that if armor is strong enough to stop a given bullet, it will do so almost completely. And if it is not strong enough, it will have almost no effect. So, if you are wearing typical melee armor and someone shoots you with a low caliber weapon, you might as well be naked. Likewise, if you are wearing ballistic armor rated for small arms and someone shoots you with a military assault rifle, you might as well be naked. But if you were shot with a low caliber pistol in a location protected by the appropriate armor, you will be (almost) completely unhurt.

The Rubble and Ruin setting. The game is set twenty-years after the fall of a near-future world. It is our world, but technology has continued to develop until the year 2065—we have some cybernetics and a lot of biological modifications—very cyberpunk, but if the cyberpunk genre was developed in 2020 and not 1980. A lot more biomedical modifications and AI and a lot fewer mechanical modifications. Then the wars started. For 15 years, those people supporting the oligarchs fought against those people supporting their countries. Think, the technical developments of WW2 but for three times as long and starting in a much more technically advanced place. But in 2080 it comes to an end and the survivors get on with rebuilding the world.

The Mechanics

Damage. There is an old problem that goes all the way back to Aftermath! and Morrow Project. If we use fixed damage for firearms, we need a really well resolved hit-location system. Aftermath! had 30 locations and Morrow Project had even more. In Mythras we have only seven; There are two arms, two legs, abdomen, chest and head. This gives us some level of detail, but not as much as Morrow Project. Likewise, D100 games have never used fixed damage.

Another issue is the temptation to increase the number of dice rolled for damage as the weapon gets more powerful. In Mythras Firearms (which was published after Rubble and Ruin so I couldn’t use it anyway) a heavy rifle does 2d10+4 damage. That would average 15 points of damage. That would, on average, completely destroy any limb hit on a normal person. But firearms don’t really do that. A high-powered rifle might destroy a limb, or it might deliver a minor flesh wound. 

Intensity levels. All the way back in the original Chaosium Monograph version of Rubble and Ruin I introduced the idea of Risk. Levels of Risk increase the range of damage delivered while keeping the amount generally uniform. (Uniform here is math-nerd speak for following a discrete uniform distribution—each possible damage value is roughly equally probable—as in 1d6 or 1d10.) For Rubble and Ruin, I use the Intensity table from Classic Fantasy. This is not exactly uniform, but I felt it was better to have one system used throughout the Mythras family of games than to have a bunch of slightly different systems.

So that same snipper rifle (from above) in Rubble and Ruin, taking a well-aimed shot and using high powered ammunition will only deliver Intensity 10+2+2 = 14, or 2d8 damage. This will average 9 HP, which will—on average—disable a limb. But sometimes it will completely destroy the limb, and other times it will—occasionally—only graze the limb. Not so cinematic as other systems, but more aligned with real observations from small group combat.

Two Armor Types. In Rubble and Ruin, I use an idea I first encountered in the game Aftermath! There are two types of armor, Melee and Ballistic.  Mythras uses Armor Points (AP). Let’s say your character is hit, the GM roll location and determines that you are hit in the right arm. You check and determine that your character has AP 2 leather on that arm arm, so if you were hit for 6 points of damage, you take 6-2 or 4 HP to the right arm. Same way we’ve been doing things since Runequest 1 in the 1970s.

In Rubble and Ruin, you simply have two types of armor, melee and ballistic. Armor points have always been AP, and ballistic armors are denoted as BP. Melee attacks work as they have always done. But ballistic armor is slightly different. Ballistic armor reduces the Intensity of the attack, changing the range of the resulting damage. So, if the aimed, high powered snipper rifle hits a character on a location protected by Kevlar it will do IN 14 - 6 or IN 10 damage. This results in a roll of 1d10 – by the way, the intensity damage table is on R&R p.69. I always have a hard time finding it.

Putting it all together

Expensive Bullets. In R&R bullets are expensive. People spent all of the Global Wars shooting at each other and that used a lot of ammunition. And that was two decades ago. Black powder is making a comeback in the larger enclaves and surviving countries, but out in the rubble, ammunition is rare.

And ballistic armor is expensive and has additional encumbrance. In early game, most characters do better not worrying about BP. If there is an encounter where someone has a firearm, treat them like you would an enemy wizard. They will have a few big, dangerous attacks. As the game progresses, the PCs will have more firearms at their disposal, but they will also tend to fight more dangerous opponents.

One caveat is that I often see players who want to run a character that sits in the back of battle shooting. This is very difficult to do, rules as written, in the early game. You just can’t afford it. Sure, everyone wants to stay away from dangerous combat and just occasionally shot at a bad guy. But in R&R your characters don’t start rich, so you have to take the risks and get into the fight.

Cheap bullets. There is no reason why a GM couldn’t run a game where ammunition was inexpensive. If this is done, play will naturally shift to a different style. Characters will focus on BP armor, wearing less AP, and fights will be less hand-to-hand and more tactical, focusing on using terrain and cover to the best advantage. This matches what we see in real life. A modern firefight with small arms focuses on hiding and getting good shots on your opponent more than anything else.

 

Thank you for reading this. I’ve been wanting to explain why I built the game the way I did for some time now—and I’ve finally gotten around to it. I would love to hear your thoughts, so please feel free to leave comments below.

 

* Jeshields’ patron has a lot of great art, I recommend it. https://www.patreon.com/c/jeshields/home

When guns were deadly in TTRPGs.

 

I want to record a few recollections of early TTRPG gaming with the idea that it might help people understand why some of us played the way we did. It is a little bit ramble and meant to be light-hearted.

I’m an old-ish nerd from northern California. I was less than 10-years-old when D&D was originally published, and I was a tween before I left war-gaming for what we now call TTRPGs.

And I was there, Dude. I was there. I saw it. I played it. I was there when guns were deadly in TTRPGs!

You need to understand, I grew up in a house full of disabled military veterans. My father had brough back with him, from the south of France, two holes in his ankles that never healed. My stepfather lost much of his hearing to the big guns of the battleships in the South Pacific, and my oldest brother was boots-on-the-ground in the jungles of Viet Nam—he had more complex issues.

You should also know that in 1980s, when I was in high school, they reinstated registration for the draft in the US. They ended up not drafting anyone (so far), but we had no way to know that. There was a cold war going on.

Old school gaming. My “lived experience” of D&D in the late 1970’s was game sessions that played like jungle patrols from the war in Viet Nam. A squad of people, maybe 10 to 12, enter into a place of adventure. No one really cares about where the characters were from or their backstory, all that mattered was what they were doing. In their adventure, there will be deadly traps and dangerous enemies. Members of the group will die. Everyone has a role to play in the operation. Fighters have to hold the line. Wizards have to deliver that one massive blast. Clerics have to fight where they can and put the survivors back together before the next encounter. Thieves have to deal with the obstacles, typically the traps and doors. We’re talking grunts, radiomen, corpsmen, and tunnel rats. Sound familiar?

The Apocalypse. I first encountered post-apocalyptic gaming with TSR’s gonzo 1979 game “Gamma World”. There were talking trees and robot death tanks. I had a humanoid rabbit named Peter who attacked with a giant leap and a salvaged fire poker. It was fun, but silly. It didn’t draw people away from the dungeons.

In contrast, Morrow Project was the first thing I ever ordered by mail. I saw an ad and had to have it. Mom helped me with ordering it. Released in 1980, Morrow Project had generally simple mechanics and a cool story setting, but it had two awesome features—and as I think about it, half a dozen other cool innovations—I’m looking at cold sleep, portable fusion, psionics and more. But the two I want to talk about are the table of nuclear targets and the damage system.

At the height of the cold war, two decades before the information age and the internet, Morrow Project taught nerds about nuclear war. It listed real weapons that were actually pointed towards you—in the real world. And it had a table of places they were likely pointed at. This was groundbreaking for those who were processing the last war at the table, and useful for those of us worrying about the next.

Morrow Project also had dangerous guns. The language nerd in me really wants to write “firearms” but I’m purposefully sticking to the colloquial term “gun”. In D&D, the risk of damage from an attack is modeled by the dice rolled. The more dangerous the attack, the larger the range of possible Hit Points lost. Not Morrow Project. They recognized that a weapon typically delivers a fixed amount of destruction per impact. Instead, it is more important where the destruction occurs on the target’s body. Where the character was hit is the important roll. Not damage but hit location. Morrow Project was not the first game to do this. Certainly, Runequest had been doing it for years by then. But Morrow Project introduced the “instant kill” roll. The torso was broken into four strips numbered 1 to 4, with Torse 1 running down the center from the neck to the groin. Torso 2-4 heading out on either side. Each firearm would have an E-value calculated from its muzzle energy. Higher the value, the higher the chance the target would just die when shot.

(Just as a little aside, notice that Morrow Project’s cover was designed to look like a 1980s US military handbook.)

Aftermath! dropped the year after Morrow Project, in 1981, and is the primary game I played for the following eight to ten years. Where Morrow Project had characters emerging into a destroyed world and attempting to repair it, Aftermath! was a game about characters in a changing world. Whatever it was in your game that ended civilization, it happened twenty years ago and we are playing characters who either remember the old world or who are living their life totally in the new.

In many settings, this is a rough and brutal world with frequent hand-to-hand combat. Big, strong characters with sharp swords ruled the world—until someone showed up with a gun. Firearms and ammunition were rare. They were relics of the last world—they were the wizard’s big spell, if you would.

Aftermath! is extremely detailed. It has lots of mechanics and was not for those who feared multiple calculations with small integers. But there were five or six values that defined each firearm and one thing which made Aftermath! interesting was that you could calculate these numbers for any real-world weapon. You could take information from some gun magazine and stat a weapon for the game. And the different statistics had in-game importance.

Another key feature of Aftermath was that it recognized that armor which protects from melee attacks seldom helps against firearms. A 9mm Glock will poke holes through steel armor as if it were not there.

So what? Gaming went through a period of diversification in the early 1980s, and one of the things some of us were looking for was realism. Not everyone. But enough of us cared more about how the mechanics modeled the situation than about the story that was being told. Stories are great. I love a good three-act-rising-action adventure as much as the next person. But for early gamers, many of us realized that stories are told by the survivors, and if you want to be one of the survivors, you need to know how the world really works. And in the real-world guns are deadly and surviving is often more important than the “rule of cool”.

Thanks for taking the time to read my recollections and I hope you found them interesting. Please feel free to leave comments below.

Hey, let's end with a few more cover images. Both apocalyptic and post apocalyptic...

Wizards as an RPG did come out until the 1990s, but it was based on a 1970's movie that was popular with the people in my community. 

My Dyson Sphere Conjecture

 

This post builds on my first two. Dyson sphere types and Ringworlds.

Let's try and build a Type 3 Dyson sphere. We want something we can live inside, like a ringworld, but that (more or less) completely fills a sphere around a star. Good idea, but it suffers from one problem. It is well known by those who think about Dyson spheres that the net gravitational attraction of a point mass within a uniform shell is zero.

This is known as the Shell theorem. It is a double differential of the gravity equation--an undergraduate physics problem--but the upshot is that, for Point A, all the close mass on the left-hand side on the line is exactly counter-balanced by the greater amount of mass, which is further away, on the right-hand side of the line. And this is true, no matter how you draw the line. So a perfect mass composing a perfect shell exerts no net gravitational attraction on any point inside the shell, be it points A, B, C, or any other.

Thus, there is no gravity to hold the inhabitants to the inner surface of the shell and terrestrial life inside a Dyson Sphere won’t work.

But there may be a “hard science” answer to this problem.

What if the builders break the symmetry of the shell. Don’t imagine a shell of uniform density. Instead, give up Dyson (and Niven’s) constraint that the sphere must have the mass of Jupiter and imagine instead a sphere with a lot of mass. Start by imagining a cylinder of mass pointed towards the star. The cylinder is exactly massive enough that the end pointing towards the star has about a 1g field strength. A local gravitational attraction will develop on the ends of these cylinders. 

On this figure, the “cylinder” is shown as a triangle with the majority of the gravity-producing mass being in the center of the object. I call these individual objects, domains. The stick figure and little house on the inset are not to scale—instead we could imagine each domain having a total area approximately equal to the surface area of the Earth. 

The domain can be imagined orbiting around the star and so far everything is clear from a physics point-of-view, but–you know–why would you build such a thing.

We can now start crowding the orbit of the domain with other domains. In Stapledon’s universe, as the orbit starts to get crowded with artificial planets, the same thing is built on different orbits either closer or farther from the star. His artificial planets were spheres that rotated, but that is not required once you have the day-night screens of a ringword.

Now I’m going to evoke what I would call  a “Niven Rule”. We can tell stories on a ringworld without explaining how “scrith” works, that is, the material science that holds the whole thing together is outside of the scope of the story. In my world, the inhabitants call the material holding the whole sphere together enigma metal. In one draft—which I think was cut for the SciFidea contest—enigma metal was said to be made on non-atom material. The idea was that the building blocks of atoms could be assembled in a different way to create human-scale materials with non-atomic properties. It’s fiction, Niven said we could do it.

So instead of having domains orbit the star, I’m going to crowd a single diameter with domains and build a latticework of enigma metal and hold all the domains in place. They will be static relative to one another. Thus, we have a grid of millions of domains encircling a star, connected to each other by a lattice of enigma metal. While we are here, let’s add six cardinal directions marked with energy beams connecting the sphere to the star. These beams can be adjusted such that the sphere is actively kept in place. This avoids the instability of the whole system.

On a single domain, net gravitational attraction will taper off as you move towards the edges of each cylinder or further into the sphere. Each cylinder would create a domain that is habitable, surrounded by a ring of microgravity between adjoining domains. Under these conditions, the Dyson sphere will have about 550 million Earth-sized domains. It is an open question as to how much of each domain can have reasonable gravity. In my stories, I assume somewhat more than half. Further, if each domain's mass is a little over half that of Earth, the whole thing has the mass of a modest star. Start with an uninhabited binary star system (sorry Three Body Problem) and you have everything you need.

Some readers may have noticed a physics-based problem regarding the shell theorem and asymmetry, I’ll come back to that.

But while we are here, we can add a few more features to our sphere—quality of life elements if you would. First, we should put some baffles between the domains. We don’t need million-mile-long storms and huge flows of water vapor. Another part of our baffles should make sure that atmospheres does not leak out to the external portion of the hull. So, build a floor between the domains. And while we’re at it, we don’t want to be living the “black box radiation” problem, so let’s build a mesh over the top of each domain which controls the amount of reflected solar radiation reaching the surface.

The Energy of Night

If half the star is shielded at any given time, creating Earth-like day and night cycles on the surface of the sphere, where is the blocked energy going? Pointing it back into the star will heat it. In my sphere, much of it is being captured by the “day-night” machine and is beamed to the hull of the sphere via the six cardinal direction beacons. The remainder is captured by the mesh on top of the domains. On the exterior of the sphere there are mechanisms which capture that energy and convert it into thrust. According to my calculations, such a sphere could reasonably expect to accelerate to around 0.1 C within a million years. If you then reversed the thrust and started braking, in around two million years such a vehicle could travel between nearby galaxies.

My Dyson sphere, like Stapledon's, is a generation ship.

The Asymmetry Problem

The problem with this whole design is that if we pack the entire space of the shell with these domains, even though the domains do not form a uniform solid, they will form the equivalent of a uniform solid and we will be right back to where we started. The idea is that, from a distance an irregular solid has the same gravitational effect as a point mass located at the solid’s center of mass. You get enough of these, and you will have the equivalent of a uniform shell and this whole design falls apart.

 But consider the Square Packing problem. This is a classic example of the more generic Packing problem where we try to place as many squares within the smallest possible larger square. And the classic result of this problem is that the best answer frequently involves wedging squares together in a seemingly disordered manner creating a non-uniform distribution of squares. Here is a classic result for 11 squares.

(By Walter Trump - Own work, CC BY-SA 4.0)

Conjecture: I offer the following statement without proof. I assert there may be one or more configurations of mass that allow the domains to have a noticeable surface gravity without creating a symmetric shell and yet generally filling the majority of the surface of the sphere.

Motivation. To motivate this, we know it will work with one domain—this is the case of the planet Earth. We know we can add dozens of domains without creating a symmetric shell that negates the local gravitational attraction. The only real questions are how many domains can you add, how large can they be, and how much variation in the local gravitational attraction will you experience?

Why?

So if a sufficiently advanced society wants to spread itself to the next galaxy, they can take a binary star, break one star down to its base subatomic elements, rebuild it as a sphere around the other, build the ion optics required to capture half the remaining star's energy output, and--Bob's your uncle--you have a ship you can point off into the void.

My goal in imagining such a craft is to get the reader thinking out engineering things that are much larger than our day-to-day human scale. We can understand what we are building. We can understand why we are building it. But it is on a scale way outside anything we can currently imagine a group of humans achieving.

To build this, we have to imagine better humans! 

From Stapledon to Dyson, a few old comments

 

 (Image: Fair use, https://en.wikipedia.org/w/index.php?curid=8033254)

I’ve been working on a novel called Enigma Scout for ten years now. The story is too egg-headed to ever get “trad published” but I’m still shopping it around. That said, it took me a long time to realize that not many people are still interested in Dyson spheres, and along this ten-year journey I wrote this text as a rough draft for possible Forward. I think it’s interesting on its own.

Reclaiming Dyson Spheres

 It is 1937, fascism is on the rise in Europe, and Olaf Stapledon releases his novel “Star Maker”. He prefixes the novel with something of an apology. Why write a story that sets humanities entire existence against a grand back drop that make all of human struggles appear insignificant? He answers himself:

“… perhaps the attempt to see our turbulent world against a background of stars may, after all, increase, not lessen, the significance of the present human crisis. It may strengthen our charity towards one another.” (p.4 – of the 2019 Dover edition, Star Maker)

He then proceeds to tell a story of the intellectual development, not just of a people, or a planet, or galaxy, or even a universe, but instead of the multiverse. He tells an epic tale of unbelievable scope—complete with figures! In this tale the narrator sees civilizations rise and fall, intelligences come and go, and always a tendency for greater and greater good.

Of course, Stapledon is writing from his own time, and many of his beliefs may not be as widely held today. But it is clear that he introduced his readers to scores of fantastic ideas. By p.118 we learn:

“Great care was taken by the Symbiotic race to keep its existence hidden from the primitives, least they should lose their independence of mind.”

Doesn’t this foreshadow Star Trek’s Prime Directive by thirty years? 

A few pages later we encounter a utopian society living on artificial planets in “orbit after crowded orbit” so numerous that “the whole galaxy was dimmed” (p.134). This is where we get the idea that was to later be known as a Dyson sphere.

The name Dyson sphere comes from the English physicist Freeman Dyson. This is because in 1960 Dyson published a one-page report in the journal Science we he proposed that any search for intelligent life should consider the possibility that we might not “see” the lifeform’s star. He reasoned that the mass of a gas giant like our Jupiter could be redistributed to create a two-meter-thick shell completely encircling a star. A sufficiently advanced civilization may want to do this to fully harness the star’s available energy. The effect of such a shell would be to shift the electromagnetic emissions of a star into the microwave wavelengths.

From here I went on to start building the logic on my “three types of Dyson spheres” found here.

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.