Locus: a Pan-Dimensional GURPS Setting

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Hey there, GURPSaroonies, Happy Thursday! Today I’m taking a little break from all the rules and mechanics, and indulging in a somewhat more creative endeavor.

Locus is the name of the setting all of the games I run take place in (whether they know it or not). It is a pan-dimensional city, in the grand tradition of Cynosure, Sigil, and Nexus.


© Ryan Church

Do you remember when you first found this place? That day you first set foot in Locus, the City, the meeting point of all realities?

Your world was so small then. A backpacking trip to Europe after college seemed the grandest adventure, a chance to see new things, discover new places.

So small.

Madrid, Paris, Rome– days of drinking, nights of laughter, just being young and free and crazy, until… the hike into the Dolomites.

You and Gail and Marcelo were far off the trail, singing and laughingРand then they were both screaming. Your scream was caught in your throat, even as your mouth froze wide open. Monsters were suddenly everywhere, of all shapes and sizes, making their way here and there and totally ignoring you (when not shooting a dirty look towards the annoying shrieks).

Things with scales, and fangs, and bulbous heads, and wings, and tentacles, bizarre creatures of every form, all walking, scurrying, and flying about their business.

The jungle was still around you, but in every direction the horizon was alien– impossibly-high skyscrapers, castles on floating clouds, a swirling tornado. And the horizon didn’t end. It curved up instead of down, until looking straight up you realized you could see across to an unending patchwork of even more insane terrain– a sparkling city made of glass, lava fields spewing plumes of ash, a huge black area that seemed to swallow light, and dozens more.

The three of you eventually stopped screaming, at least audibly. You huddled together, trembling and afraid, wondering if you had all gone crazy, or died, or worse.

Marcelo was the first to go. After three months of adapting to life in the City while still searching for a way back to Earth, he was eaten on the way to the market by a swarm of carnivorous, acid-spitting butterflies. Gail lived for almost a full year, but then she stumbled into an alley with a chlorine gas atmosphere and asphyxiated before she could step back out.

Locus is a treasure chest of infinite knowledge, a hodgepodge city of denizens from thousands of worlds, and home to unfathomable science, and magic, and everything in between. But that knowledge comes with a steep price, for life is cheap here, and sudden death lurks in every corner.

So far, you’ve survived. Learned a bit of Cityspeak. Made a small place for yourself in this insane world… even a few acquaintances (the lasagna your neighbor– Zenbor, the 4-foot long sentient bee– makes is the best you’ve ever had).

But every time you pass some jungle, you can’t help but check if it’s Earth…


Locus has been percolating through my gray matter for years. “Kitchen sink” settings have long been my favorite (probably why I adore GURPS so much). It’s something I mentally fiddle with, then leave for a bit, then come back to again and again. But lately, I’ve wanted to finally get it all down on paper, to define it, codify it, and hammer out the final persisting logistical details. While I’m doing all that, I wanted to share the bare bones here first to start getting some feedback and suggestions on ways to make it even better.

This is just the briefest of overviews, and numerous details are likely to change. Please consider this a version “0.1,” just a taste of more to come.

Physically, the City inhabits the interior of a Dyson shell roughly 10 miles in diameter (with a surface area just over 300 square miles, or the size of New York city). Floating in its center is a tiny artificial star which alternates endlessly between burning brightly for 20 hours and going dark for 10. A protective sphere surrounds this “sun” out to radius of a couple miles. Within that sphere, no technology functions and no magic works. It is a complete dead zone.

On the “ground,” things are different. Some zones are home to cosmic super-science, or mighty arcane magic, or both and more. A zone’s properties– it’s physical environment as well as the laws of reality it supports– can be anything found throughout the multiverse, and zone boundaries are not always clear (alas, poor Gail).

It is unlikely the PCs would ever learn the City’s origin, whatever the GM decides it is, but this is what I have long thought for my own games.

Untold milennia ago, there existed an advanced civilization known as the Ventari. They were explorers and scientists who had harnessed the power of the multiverse itself, traveling freely between dimensions and seeking always to unravel deeper and deeper mysteries about the nature of reality itself. They created Locus as a means of studying various dimensions side-by-side. It exists as its own unique artificial reality, outside of the normal continuum. Individual zones (there are hundreds of them across the sphere’s surface) could be used to phase other realities in and out as the Ventari wished.

And then one day, they simply vanished. Some experiment, somewhere in their galaxy-spanning civilization, went awry¬†catastrophically and in the blink of an eye, their entire dimension¬†just… ceased to be.

The City, however, did not, nor is it likely to. Even without the Ventari themselves, their god-like technology continues to keep things running (note that some GMs could choose to have a handful of Ventari survivors scattered about, protected from doom by Locus, but personally, I prefer no hands¬†on the controls). The central “star” has enough fuel to burn for a few million years, most of the zones continue to function (though many are slowly showing signs of wear), and so do the bulk of the City’s autonomic functions.

There was some damage to the system, though (or perhaps it has simply degraded without proper maintenance). The most immediate effect of this is that the zones themselves will phase new dimensions in and out completely at random, though some are much more likely to shift than others (making those that have not shifted realities for years or even decades incredibly valuable).

One thing that remains functioning correctly are the City’s own defenses. They are absolutely indifferent to whatever carnage the current inhabitants of the City inflict upon one another, but any attempt to breach the central star, or dig deep enough to reach the underlying shell of the sphere, instantly triggers a lethal response (electrocution, poison gas, fire, whatever seems most effective). Locus is also protected by an army of¬†robotic defenders (shielded from magic, of course!), though they are very rarely seen. Their skin is shifting liquid metal, they appear impervious to any technological or magical harm, but most Locusians consider them just a boogeyman, a legend (whether they’re right or not will depend on the group playing).

When a zone in Locus phases in a new dimension, it will usually determine a remote area of that dimension to phase ¬†(by calculating low bio-mass readings or something. Hey, it’s magic-science). The city creates a phasic “bubble” around a like-sized area of the dimension (that is, a 100 yard x 100 yard¬†zone will place a 100 yard x 100 yard bubble), causing the area within that bubble to simultaneously exist in two places at once. It is still a part of its home dimension, but it is also a part of Locus.

It’s probably best to explain this with an example. Let’s assume that a zone in the City, about the size of my neighborhood park, is phasing in my home dimension and using the park as the bridge. It bubbles the park, which now exists both in my home dimension (as it always has) and also in Locus. This bubble is invisible and, usually, undetectable. So, as I approach the park I see nothing out of the ordinary. I can not see the City by looking at the park.

As soon as I cross the bubble, though, I can see the City. The park will still be there around me, but the edges of the bubble no longer lead to my world, they lead to the neighboring zones of Locus, so beyond the edge of the park I will see those other zones (and their inhabitants) instead.

The biggest problem for those who inadvertently discover the City is that this is a one-way trip. If I take one step into the bubble, freak out because everything has changed and immediately take two steps backwards… I won’t be back in my home dimension, I will just be two steps into the neighboring zone. There are ways, both technologically and magically, to leave a zone in Locus and continue deeper into that zone’s current dimension, and these methods are frequently used to explore (and exploit) new dimensions that come into phase with the City, but a newcomer would naturally not have access to those immediately.

The other big problem is that dimensions phase in and out all the time. So, if you are not in your home dimension when it breaks phase, you’re stuck in Locus; if you have traveled deeper into a phased dimension when it breaks phase, you’re stuck out of Locus. Sometimes I will allow players a way to detect when “the multi-phasic tachyons” begin building up or whatever, so they’ll have a rough countdown of how much longer a zone will be part of the City. All depends on the kind of game we’re shooting for.

I think that covers most of the broad strokes. I have a lot more on various dimensions and factions in the City, adventure ideas, etc., but this is the framework.

  • Locus is a pan-dimensional city located on the interior of an impossibly advanced Dyson shell.
  • It may or may not have been created by a race of dimensional travelers who wiped themselves out.
  • Beings from any and all realities are constantly finding their way to the City.
  • It’s fairly easy to be stranded either in or out of the City.

There are, clearly, any number of ways to use a setting like this.

  • You explicitly start out a campaign in Locus, giving players a rationale for creating any kind of character they want, no matter how bizarre, from any kind of reality they want. I often find things like Pinterest and the books of Wayne Barlowe helpful here for inspirational images. The Grimjack omnibuses¬†also have a lot of great ideas about life in a pan-dimensional city and the adventures that can be had.
  • You run a ‘normal’ campaign of whatever genre and setting. When it eventually begins to wane,¬†you transport the characters to Locus and continue their adventures there (assuming, of course, everyone is into that, like any other game).
  • From Locus, the PCs can relocate to whatever other dimension they want, whether for a week, a year, indefinitely, whatever (assuming the dimension doesn’t break phase with the City). So you could play pirates in the 17th century for a couple of years, have a brief interlude in Locus, and end up in Feudal Japan for the next campaign.

So, what do you think? How could you use a setting like this? Would you like to know more? What problems do you see arising? (More info on the setting in “Locus: Types of Zones.”)

Curious to hear your thoughts!

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  1. I look forwarding to visiting The City.

    One fictional series I would recommend reading for inspiration is Simon R. Green’s Nightside. Or just for reading pleasure. For those unfamiliar with the Nightside … ‘it’s always 3:00 AM … a place where dreams come true and nightmares come alive. Where one can buy anything, often at the price of your soul… or someone else’s.’

  2. I personally love it. Great idea, I can’t wait for more! The setting is definitely one you can create a slew of adventures with.

  3. SCORE! I got in your Monday game. My tabletop group is on Saturday, and I completely forgot about signups!!! *Wrew* so glad I got a spot! Your games have for my last two cons been an extreme highlight. I can’t wait!

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