Well well well, look what the shoggoth dragged in.

Fleshing out clan Iuwoi

In The Borderland Run, an adventure for Traveller by Mongoose Publishing, the travellers are hired to transport a package to the palace of clan Iuwoi on Tyokh by a deadline. Their employer doesn’t exactly know what the consequences for late delivery will be, but at the very least, the travellers will be paid less.

If you’re a player in that adventure, or might play it in the future, turn back now: there will be spoilers!

The Aslan

If you’ve never run Traveller before, or looked into the official setting much, think of the Aslan as honour-obsessed warrior-poets who basically think of all non-Aslan as incomprehensible barbarians.

They don’t have an overall government, they have many thousands of clans, some of which are vassals to another clan, but many more of which are independent. Political shenanigans are rampant.

Aslan are descended from a predator species, so they’re violent, quick to take offense, and are obsessed with owning land. To avoid destroying themselves, over the millennia they’ve developed a complex system of honour and ritualised warfare.

I really like running Aslan NPCs. You can play them as kind of like just really upstanding humans who sometimes make weird suggestions (“Why do we not simply kill this man where he stands? He is a criminal and has offended your honour!”), or have them be really steeped in Aslan culture to the point where they have trouble even dealing with money, or understanding why you have a problem with them conquering some planet (“Surely you do not think this weak president, who cannot even defend his territory, is a good ruler?”)

Fortunately, my campaign is taking place in the Trojan Reach sector, and so Aslan can show up just about anywhere.

Like in this adventure.

Background of the adventure

Many of the Aslan clans and corporations of the Trojan Reach have business interests outside Aslan space, with the Tlaiowaha and their vassals the Ahroay’if dominating trade with the human Third Imperium in particular. But they’re not the only clans: there’s also the Htyowao (vassals of the Ahroay’if), Iuwoi (unclear if they’re independent or vassals of another clan), and many more.

The Aslan prince Hteleitoirl of the Iuwoi recently set off beyond Aslan space to make a name for himself. He tried to conquer Arunisiir, which is nominally ruled by Aslan but in practice ruled by their human advisors. He failed catastrophically: many of his followers were killed or captured, and he only barely escaped. Even worse, this caused some human / Aslan business deals to collapse. It would be embarrassing but bearable if only the Iuwoi were involved but, alas, other clans (the Htyowao are named, but there are more) are affected too. And these other clans are not happy.

War is threatened and Iuwoiko, Hteleitoirl’s father the clan lord, regretfully orders the execution of his son to placate the other clans, and now the travellers have to get Hteleitoirl back home in time to be killed: yes, the cargo they have been hired to transport turns out to be an Aslan prince. They don’t know that they’re taking Hteletoirl to his execution, or that he is the one who lead the recent attack on Arunisiir, but if they win his friendship, he will explain matters to them.

Well, that’s what has happened on the surface.

In actuality, Hteleitoirl’s conquest was doomed from the start. The Htyowao managed to turn a high-ranking member of the Iuwoi traitor, learned of this expedition, arranged for mercenaries to be present to defend Arunisiir, and now are leading the call for war against the Iuwoi, saying that the failure of the Iuwoi has harmed their, the Htyowao’s, interests. Furthermore, they’re conspiring to keep Hteleitoirl from getting back to Tyokh in time, so that they can then say that the Iuwoi have, yet again, failed to do the right thing.

It’s all a set-up: either the Iuwoi face war with multiple clans, or the clan lord has to sacrifice his favourite son.

Fleshing out the Iuwoi

The module doesn’t give much information about the Iuwoi, other than that they have a palace on Tyokh and business interests in the Borderland Subsector of the Trojan Reach.

We get even less about the antagonists, the Htyowao, but they’re covered a little in other books like The Pirates of Drinax and The Trojan Reach. We learn that they’re a minor clan, vassals of the Ahroay’if, and are in conflict with a rival clan the Hkaaiheir. The Ahroay’if themselves are an incredibly wealthy trader clan, controlling 60% of the trade going through Tyokh.

The Htyowao’s motivation isn’t directly given, but I think we can infer that it’s to gain status by eliminating a trade rival of the Ahroay’if their patrons, and to look competent and honourable while doing it.

But I wanted more.

Fortunately, there is an excellent series of posts about Aslan clans by Garnfellow, which I’ve been enjoying every time a new entry came up on the Traveller subreddit. Time to roll some dice!

Major or Minor? Independent or Vassal?

I decided that the Iuwoi are an independent minor clan.

Despite the Htyowao themselves being a fairly minor clan (they’re a vassal of a vassal), they’re still able to scheme against the Iuwoi, in a fairly underhanded way, without the Ahroay’if telling them to knock it off. So the Iuwoi can’t be massively stronger than the Htyowao.

Independent Aslan Clans is a good resource on these. I figured that an Aslan clan lord would probably have his main palace and base of operations on a world the clan owns, if they have one. Since the Iuwoi palace is on Tyokh, which they definitely don’t own, then they’re probably a small clan with holdings on a handful of worlds which they share with other clans.

Rolling on the “small clan holdings” table, I got a two: the Iuwoi have holdings on a single world: Tyokh.


Ok, so the Iuwoi are a small clan who own some of Tyokh. How much?

Aslan Clan Holdings has us covered here. It specifies clan land ownership in terms of “world hexes”, where a world hex is about 870,000km^2.

Rolling on the “random clan holdings” table, I got a one: the Iuwoi have up to 11 world hexes.

Since those hexes are on Tyokh, which has a population density of 125 people per km^2 (8000km in diameter with 60% surface water, so approximately 8×10^6km^2 solid land, with a population on the order of 10 billion), it’s probably closer to 0 than 11.

Frankly, even one world hex seems pretty excessive on Tyokh if that’s all solid ground, that’s over a tenth of the planet!

Let’s roll up population and then return to this.


Aslan Clan Populations has some handy estimates of how populated Aslan worlds and clans should be, based on source material that’s already been published, and it gives a couple of tables we can roll on.

We need to know the clan holdings before we can roll the population. But I think we can safely assume the Iuwoi have under 4 world hexes, given that they’re based on the super-in-demand Tyokh. There is no way a clan which can control nearly a half of Tyokh is also weak enough for a minor clan like the Htyowao to sensibly scheme against.

I rolled a five on the “random clan population code by holdings” table, and a three on the “random clan pop multiplier” table. So that gives the Iuwoi a population of approximately 90,000.

Now let’s return to the holdings question. Tyokh has a population density of 125 people per km^2, so the Iuwoi could reasonably be packed into just 720km^2: way less than even a single world hex.

However, The Trojan Reach tells us that Tyokh’s startown is really densely populated, and the rest of the planet is much more typically Aslan: spread-out population centres with everyone having their own small bit of land, with jungle and wild animals occupying the same land as cities and palaces. And it also tells us that Aslan cities tend to have a population density of about a tenth of human cities.

I tried looking at a list of UK towns ranked by population, and picked a few in the 80,000 to 100,000 range, but a lot of them were really dense! Far more than the 125 people per km^2 which Tyokh is as a whole.

At this point I gave up. Let’s just say the Iuwoi lands have a population density of 60 Aslan per km^2, just under half that of Tyokh overall. Which means the Iuwoi own 1500km^2.

Not a lot of land, but it is a very desirable planet.

It would be very nice if a future supplement were to go into more detail about Aslan settlements, as it’s kind of hard to drill down from aggregate statistics about the entirety of Aslan space to the holdings of individual clans on particular worlds. If I run more adventures on Aslan worlds, it would be great if I knew enough to improvise a typical Aslan town, without it just feeling like a human town but where everyone is a 7 foot lion man. I want my aliens to feel alien!


The final characteristic I wanted to think about was Aslan Clan Age. There are others I could roll up, like tradition and aggression, but age seemed the most important for a small trading clan. The Iuwoi are clearly not so aggressive or traditional that they’re above or incapable of dealing significantly with humans.

Rolling on the “aslan clan age” table I got a five and a three: the Iuwoi are a fairly young clan, founded some time after 613 (by the Imperial calendar) when the Peace of Ftahalr was drawn up but before the Solomani Rim War in 950. The current year in my campaign is 1107 Imperial, so the clan is between 494 and 157 years old.

In Summary

The Iuwoi are a small young independent trading clan, with a population of 90,000 and holdings on a single world. They were founded well after Aslan settled in the Trojan Reach and yet their holdings are on a very significant trade centre, Tyokh, which probably makes some old clans, and some young but less accomplished clans, think of them as upstarts.

They’re not that powerful militarily, but still significant enough that the Htyowao couldn’t take them on alone, they had to dupe some other clans into participating in this scheme (though, that could just be because the Htyowao are also occupied by their war with the Hkaaiheir).

I think a small clan like this is a good gateway towards further adventures in Aslan space, as they can’t do everything by themselves and so need help (like the players) on occasion.