Thursday, June 11, 2009

Fun with Jumpspace

One of the constant criticisms leveled at Traveller and several other sci-fi RPGs is that the spacemaps are all in 2-d. It's a legit beef, since being three dimensional is sorta why we call it Outer Space and not Outer Plane. Among the Trav fans I've seen three basic responses to this problem:

1. The Trav maps are like roadmaps. Triple A doesn't usually mark elevations on their maps because all you need is clear directions to your destination, not feet above sea level.

2. Jumpspace, the spooky fairyland ships use to go FTL, is flatter than realspace and thus a 2-d map works just fine.

3. Shut up. We're playing a stupid game, for crying out loud.

While choices 1. and 3. have a certain appeal, I like option 2 the best because of all the rad stuff you can do with the concept of a jump plane running through the galaxy. I'm going to try to demonstrate some of these ideas with pictures, but this is my first time working with iso-type graph paper so it may be a little inept.

Figure 1 - Here we have a perfectly ordinary subsector, sitting in space minding it's own business. A jump plane map (i.e. standard subsector map) and a realspace map of this region would look identical. If you imagine a Star D floating above or below the plane, that star would be inaccessible by jump drive and hence astrographers would omit that system from the standard jump map.

Figure 2 - What if more than one jump plane cut through the galaxy? Ships on the yellow jump plane could visit systems A, B and C. Ships on the white jump plane (below and parallel to the yellow one) could visit D, E and F. Even though B and E are very close to one another, you cannot plot a jump course from one to the other because there is no jump plane connecting them. If you want to get really crazy with your campaign you could introduce a second FTL drive that doesn't use jump space at all. A merchant with a warp drive (or whatever) could make zillions of credits moving goods between B and E. Without such a drive the civilization of A, B and C would probably be completely different from that of D, E and F. They could communicate via lightspeed transmission and STL ships, but compared to the hustle bustle of life with jump drives that may not amount to much.

Figure 3 - Here we have two different jump planes, but they intersect. A ship at system A could jump to B or C but they couldn't reach D or E in a single jump, since there's no direct jump plane connection. The ship at A would have to jump to B, then jump to D or E. Obviously, a world like B could be of enormous strategic interest to the powers that be.

Figure 4 - Here the jump plane is curved vis-a-vis normal space. Here you can plot a course from A to D, but it would be a very long jump, possibly outside the range of any known drive. Jumping to B then D would be the smart thing to do for most vessels. A navigator in a ship at system C could actually plot two different courses to system B, a short one and a long one.

Figure 5 - Here's a bump in the jump plane. B and C appears to be one parsec away in real space, but the the navigator has to plot a Jump 2 to get there. The Scout service identifies these sort of hazards and marks the maps accordingly, but in uncharted space something like this could leave you in the middle of space and out of fuel.

Figure 6 - A hole in the jump plane makes travel to world C impossible. And to go from B to D requires an intermediary jump to world A.

Now imagine that the the jump plane used the the 3rd Imperium, et al., is twisted and torn and tangled in ways a hundred times more complicated than my simple examples. This would easily explains oddities in the official maps like the Antares system being in the wrong place. It would also explain why ships need both fancy nav programs and high paid navigators. You can't just point the ship at the nearest star and hope for the best.

Someone with actual skills at geometry could probably come up with additional jump plane scenarios.


  1. Neat stuff! I don't have anything to add, I just like diagrams!

  2. Y'know what figure 6 needs to be combined with? The random dungeon floorplan generator from the DMG. Roll up a "floorplan". That's the plane everyone's familiar with. But the spaces between the rooms & corridors? That's darkspace, a lost void into which no one has ever been able to jump, only trudge at sublight speeds - & from which no one has ever emerged.

  3. The (silly) quasi-rationale behind planar Traveller maps is that the relevant plane is the plane of the *galaxy* -- hence the directional terms, coreward, rimward, spinward, and trailing.

    Never mind that the milky way is much, much more than one star in thickness..... It wasn't supposed to be something that you thought about too hard. Just a tiny sop to suspension of disbelief...

    Fun Fact: the game Star Patrol had 3-d space maps.

  4. But how will be beat Khan now?

  5. Madness lies this way...

  6. I have to say that was a lot of work. I'm not sure my players ever questioned the maps very much. A few games I've seen have use 3-D maps, 2300AD comes to mind. The problem was, you always had to use the distance formula to actually see if a trip was possible, which is why even though not very scifi-ish, 2-D maps seem to be the rule rather an an exception.

  7. saved on delicious and clipped to my evernote file.

    i've loved the idea of jumpspace and it's variations ever since i first read 'a wrinkle in time.'

    @mark you are evil but it sounds like a plan

  8. SPI's Universe also had a 3d star map. As a bonus, it included all the (then) known stars within something like 30 light years of Earth.

    Sure, you had to use the Pythagorean theorem to calculate the distance traveled, but with a good calculator that wasn't hard.

    On the other hand, as far as Traveller goes, point 3 was always good enough for us. (It made as much sense as all jumps taking a week, regardless of distance or engine power...)

  9. In 2300AD the calculate distance problem was solved by using route diagrams showing all the 7.7 light year connections (the limit of 2300's FTL Drive).

    So any space setting wanting to use 3D maps can solve that issue by adopting route diagrams. Provided there is some limit on how far you can travel.

  10. The thought occurs that another option is that there is but a single jump plane that cuts through known space and that covers the X-Y.

    Z is the projection (caused by gravity) upon that jump plane (think of the classic line drawn down from the body to the plane indicating height).

    Under this idea, when you jump to the X-Y, you're pulled out by the effect of that 'projection' to the nearest Z.

    Thus jump maps are 2D objects with the location of target stars projected upon it.

    All BS realistically speaking without the famous 'yet to be discovered science behind it'. But it always worked for me.

  11. I love the implications and possibilities in Fig 4!! I started work a few months ago for something similar for a Thousand Suns campaign. There was the 2D Map approach, but characters could gain access to an ancient alien jump technology that allowed easier "funnel jumps" between stars of similar mass. So it might be faster to get from one red giant to another, even if they were on opposite sides of the map. The idea was to add an additional strategic element for what was, essentially, a race and a scavenger hunt.

  12. John Stephens1:38 PM

    Oh, not Realism vs. Playability again. Seriously, this is Older Than Dirt, it dates back to wargaming and was never satisfactorily resolved then either.

  13. You're confusing the heck out me John. I don't see how my completely hypothetical jump plane ideas could be more realistic and they sure as hell aren't more playable than standard Trav mapping.

  14. Here's an idea:

    The Jump Plane is not a physical thing, but merely a name for an area of space that has been thoroughly examined by astrophysicists and has been certified as having no big asteroid fields or planets in the way for x-light years.

    Nobody would ever go to FTL in any direction that wasn't along the plane for any length of time (random FTL collision chart, anyone?) because they'd be scared of going right into a star (as Han put it).

    So possible missions could be:

    -charting new jump planes (or jump curves or jump macaronis or jump donuts or whatever shape) or

    -(more fun)--stealing charts of effective jump planes from hostiles and hooking them together in order to get somewhere fast-ish or

    -(super-fun), altering hostile jump-plane data so they're inaccurate and cause enemy ships/fleets to collide with solar systems.

  15. All of these ideas are amazing! I am especially fond of Figure #3 for campaign purposes. The idea that one world sits at a crosswords between jump planes, thereby gaining major economic and strategic importance is perfect for Traveller and seems to have shades of Haldeman's Forever War.

    Another idea that comes to mind and is inspired by a friend's Traveller campaign from years back relates to Figures 2. Imagine there are numerous 'horizontal' jump planes and two planets lie just like B and E. How does one reach one world from the other?

    Jumpgates! STL vessels travel from one system and eventually arrive and build a jump gate at the other. A second gate is constructed back at the system the vessel launched from. Now they have a tunnel directly from one jump plane to the other through an artifical tunnel/worm hole.

    Whatta ya think?

    Barking Alien

  16. I really like figure two. The idea of two civilizations, perhaps diverging centuries ago when people still used sublight travel, but now able to communicate but effectively seperate? Cool beans! We know what they're transmitting, but who can tell what those other guys are really up to? And what if they suddenly start transmitting gibberish or stop transmitting at all?

  17. Anonymous9:18 PM

    Actually, I got around the 2d issue by stacking sectors on top of one another (6 up and 6 down). Made for a lot of work, but I had players which asked about the up and down thing too.

  18. Nice graphs! :-)

    I usually use reason 1 and 3, since these are the simple ones, but I have always thought about reason 2. Your graphs, and some comments here gives my some new nice ideas.

    I have used real 3D space in 2300AD and in a home made game, and my groups have no problem with that. They haven't had any real problem with 2D space in traveller as well, since they accept reason 1 and 3.

    Figure 2 is interesting, since this is the situation for the Elite computer game, that I am currently remapping as traveller subsectors. In Elite there are 8 "galaxies" which can be represented as sectors in traveller. To go to another galaxy, you need a special high tech galaxy drive that can only be used once.

  19. This is why I'm envious of you Jeff. Me and my damned analytical ways would have used Z numbers or written a program to display 3d maps.

    You saw past the "limitation" and took it on a trip through awesome land.

  20. Anonymous8:23 AM

    This could work for Warhammer 40k RPG.
    The Warp travale is pure chaos anyway, so you can come up with any fun and crazy stuff without worrying about verisimilitude.

  21. Haha, this reminds me of two summers ago when I was trying to create a setting for a Savage Worlds sci-fi campaign. Since I have a tendency to overdevelop my game settings, (I'm slowly recovering from this)I found that I could not get past coming up with a plausible explanation for FTL travel. I read article after article and searched the internet... finally one of my players said "Dude, if you can come up with a plausible theory of FTL travel, you have better things to do than DM an RPG."

    ...never did get that game running.

  22. I honestly wasn't aware that games other than Traveller used 2D maps with any kind of regularity ... (I'm not being a smartass, here, I sincerely have always groups Trav-style sector maps as being the Traveller equivalent of Alignment Language ... that quirky thing that this specific game has that no other game has unless they're basically a note-for-note knockoff of this game).

    The space-opera/space fantasy games I cut my teeth on either used 3D maps (Space Opera, Universe, etc) or conspicuously avoided mapping more than very finite areas of space (Star Wars, Star Trek, my own early homebrews), and during my GURPS phase (I'm better, now) it was all 3D maps as well.

    All that said, your post is brilliant.

  23. Another possibility which isn't really easily captured on a diagram is non-reflexive jump distances. In short, the distance from A to B may not be the same as the distance from B to A.

    Too bad if all your probes and measurements and calculations tell you that to get from Aldromix IV to Gerald's World is Jump-2 ... once you get there you discover that it's Jump-4 to get home again and you can't make it!

    This could lead to circuits of jumps where it's always better to go "downhill" rather than "uphill" to get back to where you started, like an Escher circular staircase. The "uphill" planets could effectively blockade the "downhill" planets - until the "downhill" planets ally with their own "downhill" neighbours and negotiate passage for their invasion fleet to surprise their "uphill" adversary.

    Need a explanation for the players as to how this is possible? Perhaps the "aether" is moving with respect to the galaxy - Michelson and Morley were wrong!