"Hex-Crawling" the Shackleton Expanse

I’m preparing this for my own group to be used in time, yet thought I could share it and humbly request for comments. tl;dr: This is a combination of lots of random tables found throughout all of the STA books and supplements.

We, as a group, love world building and particularly enjoyed Traveller. We would spend evenings just creating a new system and society and see our hex-map expand and diversify. While I don’t think that we will delve too much into it with STA, I’m curious enough to think about the question:

How would one “hex-crawl” the Shackleton Expanse?

“Hex Crawling” the Shackleton Expanse

No, I’m not proposing to set up real hexes. Yet, if one wanted, one could indeed populate the map with sectors and systems, coordinates and all. If one would want to do that, this guide is to help out with the (randomised) generation process.

It refers to random tables of the following publications (in order of publication date):

  • Core Rulebook (all Core Rulebook tables are found in the Klingon Core Rulebook and the Tricorder Set Digest Rulebook, as well; yet, these books are not cited with exact pages), cited as CRB
  • Science Division, cited as SCD
  • Shackleton Expanse Campaign Guide, cited as SECG
  • Gamemaster’s Guide, cited as GMG

I think you should buy these books, because they’re all great. Therefore, I will leave out details and processes that are described in the books, focusing on ideas how different systems can be combined and plugged together to increase the random table worldbuilding fun. :slight_smile:

The Grand Scale

“Space is big. You just won’t believe how vastly, hugely, mind-bogglingly big it is.” (Douglas Adams)
We know that the Shackleton Expanse is “located in the Orion-Cygnus Arm of the Milky Way” (SECG p. 23). It stretches “between 120 and 180 light-years accross” (SECG p. 302). Since we can assume the yellow squares on the Star Maps in CRB and the 4 Quadrant Books to measure a “sector” (CRB p. 205), only about a third to half of the Expanse is visible on the map – and only in two dimensions.

Yet, in these two dimensions as shown on the maps and assuming a “sector” to measure 20 light years³ (SECG p. 306) we would go with “about 6 by about 9” sectors, i.e. 54 sectors in one 2-dimensional “layer”.

Space, however, is not only mind-boggingly big, but also three-dimensional. The “thickness” of Milky Way’s Disk is written to be about 1,000–2,000 light-years. This would give us up to 100 layers or 5,400 sectors to generate. That is, obviously, insanely big and more than enough for several lifetimes of adventuring the Shackleton Expanse. Enjoy!

I want, however, to propose three more reasonable approaches:

  1. Reduce the “thickness” of the Expanse. Matter in the Milky Way is not evenly distributed and the Expanse is stuffed full of gravitation. So it’s safe to assume that there could be systems of some sort “belonging” to the Shackleton Expanse 1,000 light-years “over” or “below” the galactic disk’s median – yet that would be so few systems that we can ignore them. Instead, we can assume that the Expanse itself would be “compressed” near to the galactic disk. I’m just making up the numbers here, but I think a “thickness” of the expanse of 100–200 light-years sounds more reasonable, leaving us with 5–10 instead of 100 layers. That’s still 270–540 sectors and still insane.
  2. Re-arrange the expanse to be less cubic. I imagine the Expanse to be more potatoe-shaped. Thus, there would be much empty space around the edges of the cube , so empty that we can virtually ignore such sectors. This would leave us with a “middle layer” located on the galactic disk’s median that is represented by the measurements on the map, and 4–9 layers that are located on top and beneath. With every layer put on top or below this middle layer, I’d halve the number of “populated” sectors. With 5 layers total (see above), there would be two layers above and two layers below, comprising of 27 and 13 (or 14) sectors, each. That’s “only” 124-ish sectors. I would re-arrange sectors in a way that (normally) every sector-cube’s side is connected to the side of at least another cube.
  3. Just generate one layer. Or one just stays on a landscape map and simply generates about 50 sectors for the Expanse and is done with it. This will be completely fine for years of adventuring in the expanse, as a sector will, on average, contain about 7 interesting systems, adding up to >350 times of you(r GM) saying: “You’re the first Starfleet vessel to enter and survey this system.”

Allocate Regions

The Shackleton Expanse Campaign Guide defines 5 regions within the Expanse (SECG p. 305). You should allocate each sector to one of this region. I would encourage you to define one or two additional regions as you see fit, for notable “galactic terrain” see CRB p. 152 ff.

System Generation

After every sector is set within a region of the Expanse, you can start to generate them all, one by one. For every system within the sector, follow the rules on SECG p. 302 ff. and let me offer the following additions:

Inhabited Worlds

Use the “Habitable Planetary Type” table (Table 10-2, CRB p. 308) to determine the primary habitable world’s class. Note that the SECG seems to use a different “Class K” than the CRB.
Also, roll once on the “Planetary Features of Interest” table (Table 10-4, CRB p. 308). Yet, modify the table to simply say “Inhabitants” for any line that refers to “inhabitants” on this table.

Instead of rolling a second time on this table, roll a Challenge Dice:

  • On a 1, add a unique alien to this planet (as described in the “Creating Aliens” section in the SCD p. 97 ff.)
  • On a 2, roll on Table 10-2 (see above) for a second time
  • On a blank face, add Inhabitants to this planet
  • If an effect is rolled, there are environmental dangers on the planet as described in the CRB p. 145 ff. / SCD p. 104 ff.


For each time you rolled “Inhabitants”, now create a culture that lives on the habitable world:

  • Determine their society / tech level by rolling on table 07404 in the GMG p. 244
  • Determine the dominant religion (if any) by rolling on table 07403 in the GMG p. 241
  • Determine their cultural trait by rolling on the respective table in the SCD p. 101
  • Determine their government type by rolling on table 07401 in the GMG p. 240

You can roll on each table on p. 290 of the CRB to get inspiration on physical, mental, behavioural or cultural traits of the inhabitants. You might also find inspiration on their biology and further traits within the alien creation process described in the SCD p. 97 ff.

Further Worlds

For the creation of further worlds, note that the SECG seems to use other planetary Class designations than the CRB. Some classes described in the CRB do not appear within the SECG tables (et vice versa).

Spatial Phenomena

To randomly determine the number of notable spatial phenomena within a given sector, roll again on the “Number of Notable Systems” table of the SECG p. 302 and also roll a challenge dice. Halve the number that you got off the table, rounding down. Don’t forget to create new systems… :wink:

Finishing Touches

Note that there are several known worlds and phenomena listed in the SECG (e.g. the Pinwheel or the Homeworlds of the species described in the SECG). These places need to be allocated sectors (and, if you use them, coordinates). Note also that there are some interesting places missing in these random tables. Consult the information on planet creation (esp. CRB p. 307) and all the information on stellar phenomena spread over all the different publications. Think of, e.g. black holes, particle fountains, novae etc.

If you own the Division Supplements, think of randomly determining a department and then rolling on the appropriate table(s) in the Division Supplements to find appropriate plot components.

Crawling and Fog of War

One finishing remark: Part of the fun of hex-crawling, in my opinion, is the fog of war. Even if many (or all) sectors of the Expanse are populated with systems and species (and maybe even plots): The players should have to find out, first.

I would designate the following four stages of discovery / knowledge about systems (that, by the way, also serve great as traits):

  1. Uncharted: The sector is not even charted for the star charts and completely unknown to the players. They do, however know that the sector exists and will very likely contain notable systems and/or phenomena. If the sector is assigned a number / designation, the player will know this designation.
  2. Charted Sector: Telescopes and long-range sensors charted the sector. The players know the total of systems and phenomena, the general type of phenomena (e.g. ion storms present, but not ion storms class III present) and the spectral and luminosity class of the systems’ star(s).
  3. Charted System: Systems that are charted were visited by automated probes or the long-range sensors of ships within the vincinity. Players know whether the systems are inhabited and should generally know about the society / tech level of each of the inhabiting species (they do not know if it’s dramatically appropriate for the plot).
  4. Surveyed System: The players have visited (or are visiting) the system and did some scanning. At any given time, they know everything that is dramatically appropriate/necessary at that point in time.

At the start of a crawl, all sectors but one should have the uncharted quality. One sector should be charted and should contain two ore more charted systems. The player can then decide where to start their journey through the expanse. If the campaign features an admiralty level, this could contain plots revolving around charting new sectors and systems by sending (limited amounts of) probes or even the players to certain coordinates to do some cartographing.

That’s all, folks, thank you for reading (and commenting).


I very much agree. The reason we stopped playing Traveller years ago was the game went from exploring to unknown to playing within vast empires. Yes we could have still played to old exploration type game, but pretty much all the game support switched to “empires” and life became too busy to leave enough free time to build everything ourselves or to extract/untangle the published material.

A Trek style exploration game sounds like a winner.

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Additional Advise for Planet Creation

Pages 145 ff. CRB provide advise for the creation of planets. Yet, you have to create your random tables yourself. This is easily done as follows.


For each class, an average gravity range is given. Substract the lower value from the upper value and divide this difference by ten. Write a table from 2–12 and assign the lower value to 2. For each key above 2, add the result of the division you made before. The upper value will be assigned to 12. Now, you have a random table you can roll on with 2d6. The results are distributed on a bell curve, i.e. most of your planets’ gravity will be more or less average of the average. :slight_smile:


Each planet class lists dangers (e.g. radiation). Each danger comes with a descriptor (e.g. deadly). For any danger that is listed multiple times (but with different descriptors) randomly pick one descriptor. If the danger is described as possibly present, roll one Challenge Die: only if an effect is rolled, the danger is present.

Note: The chance to roll an effect on a Challenge Die is one out of three, i.e. 1/3. If you want to have a 50:50 chance, take “one or effect”.

Also note that dangers (especially temperature and radiation) should probably be linked to type of and distant to the solar system’s star(s). This would, however, include more complexity that I have not (yet) thought about. :slight_smile:

Am I misunderstanding the math, here, or does that result in 11 and 12 giving the same value? I mean, I guess that’s not a problem; I’m just trying to understand.


It should not.

Let’s say we got an average between 0.5 and 1.5. The difference is 1, so the steps are 0.1 - then the table looks like:
02 – 0.5
03 – 0.6
04 – 0.7
05 – 0.8
06 – 0.9
07 – 1.0
08 – 1.1
09 – 1.2
10 – 1.3
11 – 1.4
12 – 1.5

Maybe I just failed in the language. :slight_smile:

Gar. No. I’m doing the mental equivalent of the classic computer programmer “off by 1” error. In my mind there are eleven “slots” but the delta is only divided by ten, so it seems like the math doesn’t line up. I should have sat down and wrote out an example before posting, 'cause now I just look foolish.

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Let’s just say that I double-checked my advise (with a hand-written table, just to be sure) because I did the same error while devising my method. Twice. :slight_smile:

And then I went: “Gosh’ they’re right, I f’ed it up!” when you posted.

Hah! Who’s the fool now?!! :wink:


Sorry, I just had to throw that in. :grin:


@Modiphius-Jim This one’s quite a bit technical, but:
Chapter 10 (Stellar Cartography) of the Shackleton Expanse Campaign Guide repeatedly refers to “Class O” spectral class/type (cf. e.g. p. 303, modifiers table on p. 305). Yet, neither the Spectral Class table, the Special Spectral table nor the Notable Spatial Phenomena table contain any O-type stars.

What am I missing? :slight_smile:

Wikipedia says that L/Y/T are categories of red and brown dwarf, so it feels like there’s some redundancy between the L/Y/T and the Brown Dwarf categories on the Special Spectral Table on pg. 303.

Page 303 also has this line, “Note that results of II, II, Ib, or Ia along with the spectral type…”

Is Luminosity II simply repeated, or should the first instance say III?


I stumbled over the same issue and decided to interpret it as a typo. So, it probably should indeed say III.

If we don’t have ‘O’, then we can’t use the mnemonic, “Oh Be A Fine Gorn, Kiss Me”.


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maybe it helps

Naw, we’re talking Class O stars (the great big blue giant stars), not Class O planets.

It does seem like they’re pretty rare, though.



Yep rare, young,
Interesting * θ1 Orionis C is the brightest star in the Trapezium cluster in the Orion nebula, an O6 main sequence star with a fainter spectroscopic companion.
Maybe Orions can telll more

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I use this as a reference for my games:

Yes, but where is it (= the O-type star) on the random tables in the Shackleton Expanse Book? :slight_smile:

Seems to be missing. It should be in the Special Spectral Table. I’d modify it that a 4-5 means Class B and 6 means Class O. The rest stays the same. Class A is more abundant than Class B, so changing the table this way makes sense to me.

Don’t recall what happened since the book was done more than a year ago. Here’s the special spectral table from the pre-layout draft. Maybe this helps?

1-2 Class A
3-4 Class B
5-6 Class O
7-11 Class L/Y/T
12-13 White Dwarf
14-15 Brown Dwarf
16-20 Roll on the Notable Spatial Phenomena Table

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It is for a different game but Coriolis Atlas Compendium has a pretty quick set of tables to generate systems and planets that should work in just about any setting.

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