How to do a 3D Star Map that’s Not Overwhelming

Image result for traveller sector map

Flat Star Chart (click for source)

(For my alternative to 3D mapping, scroll down.)

I’ve been revisiting Traveller RPG. One thing that’s not changed over the years is that the star charts are flat. Here’s an example (right). As a kid I hated this. I’d have said that it was because it just wasn’t a proper simulation! Space is 3D, right? I actually spent — wasted — time trying to make 3D star charts.

Then a game called Space Opera came along and that did have 3D charts. I thought this was the best thing since the BBC B Micro computer — 32K!

Unfortunately, the maps were way too hard to comprehend. Navigation was a chore… a trigonometric chore. They also didn’t really add that much to what play we got out of the game.

Image result for fgu space opera star chart

Space Opera is 3D (and hard to play)

It was simply too much overhead and too overwhelming. A truly 3D star chart needs a computer interface — not available to me back in the 1980s, and a bit of an intrusion into tabletop gaming, not least because it would be hard for a GM to add stuff on the fly without breaking flow to fiddle with the laptop.

This brings us back to flat star charts as “good enough”.

There’s a particularly compelling blog post (here) that makes the simple argument:

…when the PCs reach new worlds there will be things they don’t know, whether it be details of the environment, changes in local politics, and so on. And then, when they turn around, they’ll be making the same calculated risk (or broad gambles) they made when they made the half of the journeys. The Age of Sails is a common reference in Classic Traveller (and rightly so). In this tradition, the Player Characters travelling half way up a subsector are like sailors make their way from England down and around the Cape of South Africa

So flat star charts are an abstraction like Zones in Fate. It certainly works well enough — the Traveller universe is well-loved and well-trodden. I was a fool and should have gotten on with enjoying the actual roleplaying.

Even so, I still don’t like the Traveller 2D astrogation charts! My reasons are the same as when I was a teenager,  however — three decades later — I am better able to articulate them…

Traveller Map

Where is the overwhelming freedom of choice?

The careers and incidents of Traveller’s character generation clearly emulate a sprawling universe where:

  • Colonial style warfare is endemic, much like in 19th century — e.g. marines take part in planetary assaults, get stuck behind enemy lines.
  • There are vast reaches of terra incognita — e.g. scouts survey new systems and make first contact.

The rules in general support genre tropes consistent with this:

  • Marginal or forgotten human settlements — where adventure can happen.
  • Interstellar trading is an adventure.
  • Imperfect travel information — there is no Hitchhiker’s Guide to the Traveller Galaxy.

Though the Referee can make all these things so by fiat, a flat map presents too ordered, too known a domain for them to emerge organically.

I mean, where are the blanks in that map? Sure, there are some systems that probably require surveying, but we’re talking a brief phase of exploration. Where are the hot spots? Where is the overwhelming freedom of choice?

In short, the Traveller rules support Dumarest and Firefly, but the map does not.

My Solution: Fractal Space

I have a tentative fix which I call FRACTAL SPACE. I shall be trialling it on my own sandbox game and am already using in a forthcoming novel. Here is a rough attempt at it:

Sample Star Map

Fractal Space

It’s not rocket science! It’s probably not the first time somebody has come up with it. Here’s how it works:

  • Wormhole connections are fractal, like several big trees growing out of the galactic centre. 
  • Each system potentially has several wormhole connections, however only a few are known.
  • The branches are not (generally) cross-connected. 
  • Twigs are occasionally connected by “runners”. 
  • There’s usually only one known route between given systems.

New wormholes potentially connect to:

  • Useful new shortcuts. 
  • Backdoors into hostile empires!
  • Unlimited unexplored worlds (because each system has new exits.)
  • Undiscovered civilisations.

The effect on adventure-friendly activities is:

  • Scouting: There’s always new exploration to be done (because fractal). The activity can’t be automated (because any wormhole may lead to contact with aliens etc.)
  • Trading: Wiley traders may know shortcuts.
  • Archaeology:  Ancient history  has strategic significance, because investigations may reveal evidence of lost wormholes, especially runners.
  • Military: All borders are potentially porous. An undiscovered wormhole may, at any time, disgorge an armada of genocidal aliens!
  • Colonisation: Assuming habitable worlds, the frontier is endless, giving rise to countless quirky settlements or near-empty planets.
  • Travelling:  It’s possible to wander the stars almost indefinitely. 

For me, as both a writer and a GM it has the following advantages:

  • Star charts still make intuitive sense.
  • Strategy implicit in charts.
  • Possible to plug-in new settings almost anywhere.
  • Almost endless possibility, but still manageable.
  • The thrill of exploration.

I’ll let you know how this goes…

M Harold Page is the author of The Wreck of the Marissa (The Eternal Dome of the Unknowable #1), a modern Pulp space adventure about a mercenary-turned archaeologist and his quest for the ultimate alien artefact. 


Writer. Swordsman. CLICK TO SEE MY BOOKS !

Posted in Blog Post, Roleplaying, Space Opera Tagged with: , ,
4 comments on “How to do a 3D Star Map that’s Not Overwhelming
  1. This is great. In fact it has been done before, by no less a person than David Weber (of Honor Harrington fame) and his cohorts at Task Force Games, in the original Starfire campaign module, “Empires III”. That setting had thirty six worlds, numbered 11, 12, 13, etc, up to 66. You could randomly roll up a system using d6’s treated as percentile dice. Each system had a number of jump points, and you would only know where they went when you sent a ship through to the other side.

    The upgraded version, called “New Empires” featured a similar mechanism, but with a much bigger map, of one thousand worlds, you would randomly generate one by rolling three d10s. A system in New Empires would have a number of known jump points, determined when the system was discovered the first time. Once those were all determined (by the simple process of being assigned by the first routes that lead to or from that system, then any other jumps that would lead to that system were one way jump points, you couldn’t return the way you came.

    An elegant system, and I think your version is a great idea for Traveller.

  2. Geoff Hart says:

    I came up with something similar, but to simplify the mechanics, I chose a simple rule of “physics” to constrain how interstellar travel worked: a wormhole existed between any given system and the one system that was nearest to it as the space-crow flies. The entry and exit points lay at a predictable (astrogatable!) distance between the two systems on a line connecting their centers of mass at a mathematically defined distance from the sun (usually out past the asteroid belt). Gravity, don’t you know. *G*

    It worked really well because it preserved the 3D feel without actually requiring a 3D implementation. I left open the possibility of undiscovered wormholes that passed between an intermediary system such as a brown dwarf that was not visible to most players (really patient astrophysicists being an exception) but of keen interest to the military, for obvious reasons. Such links were rare, and were closely (ruthlessly) guarded secrets.

    My biggest problem as GM was always how to constrain the players so that they would only go to worlds I had developed in enough detail to support role-playing if they subverted my expectations and went somewhere unplanned. The way I solved that was twofold: I made them either “direct employees” of the local empire, so that they went where they were told, just like Captain Kirk and crew, or made them “privateers”, working for a planet or empire, so that they had some freedom but were still operating under generalized orders (e.g., get to know the Hydra Quadrant so you can report back on whether a rebellion is brewing and cut off its head if we deem it expedient). The second solution was generally more fun (gave players more of a sense of freedom), but both solved the problem of explaining how PCs gained access to military-grade ships capable of surviving the myriad insults proferred by a hostile universe.

    One example of a story loosely inspired by how one group of PCs planned a typical “mission” in my game universe:

  3. PlanetNiles says:

    Your fractal mapping system is almost identical to the star maps for the space 4x game Aurora. It even has “Runners”. I can spend ages reorganising my maps so that all the jump routes are horizontal, vertical or at 45 degrees, like the London Underground map. Then a new jump route loops back across the map and I have to start all over again.

    I’ve always treated the 2d Traveller maps as maps of jump space rather than physical space. When/if the issue comes up.

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