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#4, #5: Setting A Campaign: Sectors of the Imperium

The first part of this column originally appeared in Shannons column on the RPG.Net website in October 2009 as Fifth Imperium #4, and the second part in November 2009 as Fifth Imperium #5, and appear combined in issue 002 of Freelance Traveller.

Three months ago I kicked this column off with Setting a Campaign: Eras of the Imperium, which provided an overview of the 5000-year period which has been well-detailed within the canon of Traveller and which is available for you to center your own campaign within.

Most of those far-flung eras have their own, corresponding locales. The Interstellar Wars are set mainly within the Solomani Rim, Milieu 0 centers upon the Sylean stars, and the Gateway Era focuses on the Gateway Domain. However, once your approach the best-developed Traveller campaign settings—starting with the Golden Age that was the basis for both Classic Traveller and Mongoose Traveller—you'll find that there are a wide variety of different settings you can use, spanning the length and breadth of the Third Imperium ... and lands beyond.

An Overview of Space

Space in the Traveller universe is broadly divided in three different ways.

First, you have clusters, which are a relatively new geographical notation, mainly pushed by Martin Dougherty through the T20, Classic Traveller, and Mongoose Traveller books published by Avenger Enterprises. A cluster is a set of 10 or 20 stars that are bound together by politics and/or by geographical closeness.

Second, you have sectors, which are an official geographical designation within the Third Imperium. They encompass all of the stars within a grid that's 3240 parsecs (and which includes sixteen 810 subsectors). Going back to Classic Traveller days, campaigns were typically defined by a sector.

Third, you have domains, which are also official Third Imperium geographical designations, and which include four sectors arranged in a square. They're ruled over by an Archduke. In the MegaTraveller era, DGP started to write about the Domain of Deneb, an area which included the Spinward Marches, the Deneb Sector, the Trojan Reach(es) sector, and the Reft sector. Some more recent books have also detailed four-sector areas.

For the purposes of this article, I'm going to mainly talk about sectors, as that's overall the most frequent size for a campaign setting, though you'll see one domain and a number of well-detailed sectors that have less well-detailed sectors nearby.

With that said, here's a look at the many sectors that you can set your campaigns in. In this article, I'm going to cover the first half of them, from Core (at the center of the Imperium) to the Hinterworlds (on one of its frontiers).

If you'd like detailed information on the stars of the sectors, I'll point you to The Traveller Map (http://www.travellermap.com), a superb resource that we only could have dreamed of back in the 1980s, when I was last an active Traveller fan.

Traveller Sectors: Core to the Hinterworlds

Core Sector. The Core Sector could offer an interesting basis for a very political campaign, as it's the center of the Imperium. As we'll see, it's also one of just a few campaign settings that lies toward the interior of the Imperium rather than sitting upon a frontier.

Unfortunately, the material detailing Core is pretty limited. All of the Milieu 0 material for Traveller 4 (aka Marc Miller's Traveller) is set in the area, but some of it's pretty bad (other, perhaps, then the main book, Milieu 0)--and it is 1000 years out of date if you want to to run a Mongoose-era campaign. However, you could supplement the T4 material with information from issues #9-10 of The Traveller's Digest and maybe also with some of the books and articles detailing Imperium nobles [nobles] .

Generally, however, Core is one of the weaker settings that I'll be suggesting in these articles, and it's included mainly because of the information produced in the T4 days.

Diaspora Sector. During the first part of the MegaTraveller era, GDW flailed around a lot without establishing a base campaign setting. There was a half-hearted attempt to introduce a sector in Challenge magazine in 1989 (the Hinterworlds, which I'll return to at the end of this article), but it wasn't until 1992, five years after the release of MegaTraveller, that the game got a home base: the Diaspora sector.

Diaspora lies just coreward of the Solomani Rim and just spinward of the Old Expanses, two other sectors that I'll be discussing in this article series. Thus, it lies in good relation to a few other Traveller game settings. It's also almost entirely the vision of one author, Charles E. Gannon, who not only wrote the primary sourcebook for the area, but also wrote many adventures and other articles in the setting, for both Challenge and Traveller Chronicle magazines.

However, other than that those plusses, I don't find Diaspora a very good locale for most eras of Traveller play. Firstly, that's because it's a pretty central sector of the Imperium--and unlike Core, it doesn't have a lot generally going on. That means it's not very interesting until the Rebellion starts breaking the Imperium apart, and that's probably out of scope for your Mongoose campaign. Second, almost all of the description of the sector comes from sourcebooks set in the Hard Times era, which is markedly different than how the sector would have been in the Golden Age, before the Rebellion caused it to shatter.

If you're nonetheless interested in the sector, you can find the best information in Astrogators' Guide to the Diaspora Sector and in Traveller Chronicle #2-6 (though Traveller Chronicle, which I'll be mentioning throughout this series, as it's generally a great source for setting material, is relatively hard and/or expensive to collect; I'm still missing a couple of issues from my own set).

I should also note that Diaspora (and Old Expanses, which I'll talk about later) was the main setting for Traveller: The New Era, though things have changed so much by then that the the data for that era is largely useless for any other play.

And now, having talking about two sectors that are pretty outside the norm for Traveller campaigns, I'm going to plunging into the frontiers more typical for the game ...

Far Frontiers Sector. In the days of yore there was an event called the Great Land Grant. This was when a very young GDW supported its early licensees by giving them sectors in the Official Traveller Universe to play with. We'll meet a number of these land grants over the course of this article series. One of them was the Far Frontiers sector, which was the official sector of FASA.

The Far Frontiers Sector is one of the furthest flung of all of the official sectors of Traveller (only exceeded by Group One's Theta Borealis Sector). It lies two sectors spinward of The Spinward Marches, just past Foreven. Half of the sector is dominated by the Zhodani Consulate, while the other half contains a number of pocket empires, some of which support the Zhodani and some of which support the Third Imperium.

All of the FASA adventures were set in the Far Frontiers sector, which is probably the prime reason to run a game there; many of FASA's thinking-man Traveller adventures are considered classics. Unfortunately, there was no official description of the sector as a whole until well after FASA stopped publishing. If you decide to run in Far Frontiers, you'll probably need to pick up Ares Magazine Special Edition #2 (which had a short article on part of the sector) or else Traveller Chronicle #2-8, which expanded that article, then went well beyond it to produce a very complete look at the area.

If you wanted to expand the Far Frontiers sector into a full domain-sized area of space, you could supplement it with the Foreven Sector to trailing (which I'll talk about next) as well as the Vanguard Reaches Sector to rimward and the Beyond Sector to trailing-rimward. The latter two sectors were land grants to Paranoia Press, but I haven't given them full descriptions in this article series because they were the foundations of their own sector books and not much else (Paranoia Press spent most of their time putting out rule books and gaming accessories, not settings or adventures).

Foreven Sector. The Foreven Sector lies just spinward of The Spinward Marches, so it should be a great place for adventure, especially since it's even more of a melting pot of the Zhodani and the Imperium than the Spinward Marches, with several client states of each of these mighty empires lying scattered between them (much like the Far Frontiers sector). Unfortunately, it's received almost no support to date, and is now officially a "blank land", open for any GM's individual interpretation.

Personally, I hate blank lands, because as a GM you have the ability to replace anything that you want anyway. Naming Foreven a blank land just means that we'll never get an official look at an area that should be pretty important to many campaigns because of its proximity to the Marches. On the plus side, you can download an official outline of Foreven Sector online. In addition, some third-party Traveller publishers (namely, Hell Creek Sanitarium, Jon Brazer Enterprises, and K Studio) are just now starting to publish Foreven Sector supplements, under a special license from Far Futures.

At the moment Foreven is too sparse to run a campaign within, unless you do a lot of work on your own. However, I suspect that'll change within the next year.

Gateway Domain. The one area of the Traveller universe that's always been described as a domain is the Gateway Domain. It includes Crucis Margin Sector, Gateway Sector (aka Maranatha-Alkahest Sector), Glimmerdrift Reaches, and Ley Sector. The Gateway Domain is an interesting locale because it's a set of largely unaffiliated worlds and clusters that lies between the K'Kree's Two Thousand Worlds, the Hiver Federation, and the Third Imperium. This is the sort of true frontier that's been the heart of most of the Traveller campaign settings: just on the edge of the Imperium and interfacing with a couple of other societies.

Of the various sectors I've described in this article, the Gateway Domain is the only one that has had two largely incompatible descriptions.

The Gateway Domain was originally the home of the Judges Guild Traveller supplements (and thus the earliest land grant). Judges Guild published all four sectors as standalone books and put out numerous adventures set in them. For reasons that boggle me, GDW decided to throw out all of Judges Guild's work by revising all the star positions and names when they published the Atlas of the Imperium. Still, if you want a fully detailed domain supported by almost 20 modules, the materials describing the non-canon Gateway Domain are all still out there (though from what I hear, the adventures aren't that great on average).

In more recent years a new, canon version of the Gateway Domain has been published in two very well-received books. The first was MegaTraveller Journal #4, which features "Lords of Thunder", an extensive campaign by the Keith brothers, set in the Rebellion time period. The second was Gateway to Destiny, which was set in the Gatway era, when the nearby wars between the Solomani and the Third Imperium have their own effects upon this region. There are several PDF adventures and sourcebooks which have followed up on this latter book, making it a very rich location for adventure.

Besides the four sectors that make up the Gateway Domain, proper, there are also two nearby sectors that have received some attention. One is The Hinterworlds, which lies just rimward, and which I'll talk about separately, because it was released as a standalone sector (and in a different time period). The other is the Empty Quarter Sector, which has been the default sector for the online fanzine, Stellar Reaches; it's been presented largely as an add-on to the Gateway Domain and lies just coreward.

Though I'll talk about the big two Traveller campaign settings—The Solomani Rim and the Spinward Marches—in my next article, the Gateway Domain certainly has the potential to be the third, thanks to the fact that it's a real nexus for stories and that it's been detailed in good books by some of the top authors for the game. Unfortunately Mongoose GMs will have to extrapolate from these sourcebooks to come up with an 1105 Golden Age Gateway setting.

Hinterworlds. We've already looked at Diaspora, the second sector for MegaTraveller. GDW's first half-hearted attempt to detail a sector for MegaTraveller occurred when they detailed the Hinterworlds sector in Challenge #39.

It's a sector with as much potential as the classic frontier sectors of Traveller, because it's situated between the Third Imperium, the (somewhat distant) Two Thousand Worlds, and the Hiver Federations. Thus, as with the other true frontiers, you've got a few different alien races competing with the Imperium. Even better, the sector itself belongs to no one, but instead is the home for a bunch of pocket empires.

Unfortunately, the sector was never supported, except as a place to set Challenge Magazine articles. As such, it's probably largely forgotten and inaccessible to modern Traveller GMs.

Traveller Sectors: Old Expanses to the Trojan Reach

Old Expanses. This was another land grant, which is to say another sector given by GDW to one of their third-party licensees. The Old Expanses sector was the home base of the High Passage Group, a short-lived Traveller publisher whose main claim to fame was High Passage magazine.

The Old Expanses lies on the trailing border of the Third Imperium, adjoining the K'Kree's Two Thousand Worlds. It's thus another of Traveller's classic frontier sectors. Because the Old Expanses wasn't in print for very long, it's been largely overshadowed by other nearby realms like Diaspora and the Gateway domain—both of which I covered earlier. However, issues #2-5 of High Passage (which were published by FASA) are pretty easy to find, so the Old Expanses might be an interesting sector if you want just a little bit of definition for your campaign.

Old Expanses (along with the aforementioned Diaspora) was also the main setting for Traveller: The New Era, though things have changed so much by then that the the data for that era is largely useless for any other play.

Reavers' Deep Sector. The most scattered of all the Traveller sectors was the one land granted to the Keith brothers. They used it for their own Marischal Adventures folios, but also for some of their material published by FASA, Gamelords, and (eventually) Steve Jackson Games.

Located between the Third Imperium, the Solomani Sphere, and the Aslan Hierate, Reavers' Deep is yet another frontier. As is often the case, there are a number of smaller states amidst those goliaths.

There is a Reaver's Deep Sourcebook that was published in extremely limited quantities by Cargonaut Press in the late 1990s, but it's largely impossible to find now. The only other background information on the area appeared in Gamelords' A Pilot's Guide to the Drexilthar Subsector and in A Pilot's Guide to the Caledon Sector, which appeared in Traveller Chronicle #5-7. The Caledon guide has also been collected into a PDF book that was made available on Far Future's Gamelord's CD. A variety of Reavers' Deep adventures were published back in the 1980s too, while in the 1990s a variety of Reavers' Deep articles were printed in Traveller Chronicle (though many of them advanced the sector to the New Era).

Because the information is so scattered, and because it's all pretty hard to get today, Reaver's Deep probably doesn't have much value as a setting for a modern GM, but is included here for the sake of completeness.

Solomani Rim. The Solomani Rim was the second great sector of Classic Traveller, followed Spinward Marches (which we'll get to momentarily). It offers a more understandable setting for the modern player than some of the other campaigns sectors, because it centered on Earth.

The Solomani Rim isn't a great melting pot of alien races like the frontier sectors (though the Aslan and the Hivers are both pretty near), but it does offer a great story: part of the sector lies within the independent Solomani Sphere, while the rest is occupied by the Imperium, who is trying to redress old problems centering around the last Terran rebellion, about a hundred years earlier (in the Gateway Era).

There are many references on the Solomani Rim, the best of which are probably Rim of Fire for GURPS Traveller and the much older Solomani Alien Module for Classic Traveller. The Solomani's home sector is also the home of some of the later Classic Traveller adventures and double adventures.

The Solomani Rim can be used in many of the more far flung eras of the Imperium, not just the Golden Age. It's the center of the Interstellar Wars era and there's also a setting for the New Era which was published in the later issues (#10-13) of Traveller Chronicle magazine.

Spica Sector. Spica Sector would have been a bold new extension of the Traveller universe, for the first time depicting a sector mostly within the Hiver Federation, and thus full of the Hivers and their many client races. Instead Spica, as of now, is the story of the sector that didn't happen.

There were some discussions of the Spica Sector on the Citizens of the Imperium forum, but those seem gone now. Then Spica Publishing was going to publish Spica Sector books with the OK of Marc Miller, but that got canceled due to the release of Mongoose Traveller. The latest news suggests that we might still see the sector detailed in a free PDF. If so, it'll prove a nicer resource, as it's right next to the Hinterlands (which itself is adjacent to the Gateway domain and the Empty Quarter).

The Spinward Marches. The Spinward Marches is by far the best described sector in all of Traveller. Located at the spin-coreward corner of the Imperium, it's a classic frontier state where exploration and adventure are very possible. It also acts as a nice nexus, centered between the Aslan, the Vargr, the Zhodani, and the Imperium itself, upping the possibility for intrigue and even warfare.

There are complete descriptions of the Spinward Marches for almost every version of Traveller. I'll point you toward my series of Spinward Marches reviews for more information on each of them:

[Editor’s note: The list of publications that appears here are actually links on the original article at RPG.net. We strongly urge interested readers to see that article.]

Besides this plethora of overviews, there have also been many books published which describe individual subsectors, clusters, or worlds of the Marches. I'll detail these in a future article (though you can already find reviews of some of the cluster and world books in my ongoing Spinward Marches review series). In addition, most of the Classic Traveller adventures and double adventures are set in this area of space.

Finally, campaigns in the Spinward Marches can be extended by adventures in other adjacent sectors. Both the MegaTraveller Journal and the Regency Sourcebook included information on the full Domain of Deneb. In addition, other books and articles have detailed some of those sectors individually.

Besides Trojan Reach(es) and Foreven, which I've included in this article as standalone sectors, you should also look at the existing sources for Deneb Sector (which is still pretty sparse), Gvurrdon Sector (soon to be expanded by the Vargr sourcebook from Mongoose), and even the slightly more distant Corridor Sector (which got some good attention in the MegaTraveller era).

Theta Borealis Sector. The most far flung of all the Traveller campaign sectors is the Theta Borealis Sector, which was the land grant of Group One, another of the Traveller publishers of the 1980s. It's located five sectors spinward of the Third Imperium and two sectors rimward of the Zhodani Consulate, in a sector so far from the rest of the Traveller Universe that I'm not sure you could even call it part of Charted Space.

I suppose if you want a sector that doesn't have any of the traditional issues of the Third Imperium, you could go with this area, which was detailed through a number of world books and some ship-based adventures, all of which were connected together in the sector booklet, Theta Borealis Sector—but I've never seen most of the Group One books in my years of collecting Traveller.

Trojan Reach(es) Sector. Though The Trojan Reach (called the Outrim in some old sources) can be used as a supplement to the Spinward Marches, it's also strong enough to stand on its own. In some ways, it's like a sideways mirror of Foreven. There you have frontiers lying between the Imperium and the Zhodani and here you have frontiers lying between the Imperium and the Aslan. There are also some major independent states in the area, the most notable of which is the Florian League, probably my favorite minor human state. (Like the Darrians, a lot has been done to show off how the Florians can be human but still very unique.)

The reason that the Trojan Reach can be played on its own is that it's got two great resources. First, there's the recent Aslan book put out by Mongoose. But that itself was built on a Canadian fanzine of the 1980s called Third Imperium. Almost every issue of that fanzine centered on a new subsector of the Reach. Here's even better news: they're all available online, making the Trojan Reach super accessible.

Other Campaigns

The Trojan Reach is, as of this writing, the most recently published sector in the Traveller universe. By chance that also brings to an end my look at the sectors of the Traveller universe that could be used to (easily) run campaigns. But before I close out this article, I'd like to call your attention to one final campaign setting of note ...

The Grand Tour. One of the most unique campaign setting in roleplaying can be found in the pages of the 21 issues of The Travellers' Digest. That magazine centered around a 21-adventure "Grand Tour", where a group of friends are given a tour of the Imperium, from Behind the Claw to Sol and back. Along the way they hit some of the most important worlds of Charted Space, including Capitol and the Aslan Homeworld. It's a campaign truly worthy of the name "Traveller".

You can find the first four adventures of the Grand Tour in The Early Adventures. From there you'd need to collect issues #5-21 of the magazine to get the rest; it's not impossible on the internet, but probably somewhat expensive. Of course, along the way, you'll also put together a collection of one of the best magazines ever written for Traveller.

I've wanted to run The Grand Tour for years, but its 4-character setup has kept it too small for me to run any time recently; maybe some day.

Having finished my look at this set of Traveller settings, let me offer one caveat: though I've constantly linked to topical tags in the RPGnet Game Index, they're not yet complete. Consider them starting points, but not comprehensive listings of all the publications for these settings.

[Editor’s note: The links do appear in the original articles, Fifth Imperium #4 and Fifth Imperium #5, at RPG.Net. Interested readers are encouraged to follow up at that site.]


In this article I've covered several of the more detailed areas of the Traveller universe: the Core sector, the Diaspora sector, the Far Frontiers sector, the Foreven sector, the Gateway domain, and the Hinterworlds sector. Of them, I find the Core and Diaspora sectors to be of somewhat limited use because of their non-frontier nature and/or their more limited details.

However, the Gateway Domain is surely one of the great campaign settings for Traveller, the Far Frontiers is a setting with some great adventures, and the Foreven and Hinterworlds sectors could supplement other settings or stand on their own.

I’ve also covered The Solomani Rim, the Spinward Marches, Trojan Reach, Old Expanses, Reavers’ Deep, and Theta Borealis. The Solomani Rim and the Spinward Marches are the most obvious choices for a campaign, but there are other possibilities. The Trojan Reach offers a pretty good, well-supported alternative. Old Expanses, Reavers' Deep, and Theta Borealis would require a lot more hunting for old publications—and a lot more design work—but could form the foundation of a very unique Traveller game. And maybe someday Spica will receive some love.

That's it for my look at the sectors you could easily run Traveller campaigns within. I'll be back in a future issue with a final installment, looking at where in the Spinward Marches you might want to run a campaign, if you decide to choose the most obvious sector for your Traveller game (as I have).