Iblis Prime: A Homebrew Planet for Rogue Traders and Other Adventurers

The Boiling Brine

The Boiling Brine, an inland sea on the planet Iblis Prime via

For the past 28 sessions, I have been GMing a Warhammer 40k Rogue Trader game for my home group. At the end of our last story arc, the players were rewarded with the rights to a colony on a newly discovered (though presently populated) planet outside of the Imperium of Man.

Rather than give them a data dump of information and plot hooks I created, I made a session out of planet creation. I leveraged the World Generator system from Chapter 1 of the Stars of Inequity supplement, and players took turns rolling skill checks to research or investigate the planet and its system. Based on the success of their skill rolls, I granted them some leeway to choose off of the random tables from Stars of Inequity. If they failed, I chose nastier results.

After randomizing the characteristics of the planet, we set about filling in the details of some major factions of the city, creating a slew of potential allies and adversaries as they set off to make their mark for the Imperium of Man. I’ve included the results of our session as a (mostly) ready-to-play location for your Rogue Trader game, which can be easily adapted for other settings.

System Features

Star: Iblis, a yellow dwarf similar to the Terran Sun

Inner Caldera: an unexplored planet

Primary Biosphere: two habitable planets, Iblis Prime and Iblis Binary

Outer Reaches: an unexplored Asteroid Cluster

Iblis Prime Planetary Features

Iblis Prime is a small and dense rocky planet orbited by a lesser moon

Atmosphere: Moderate and pure

Habitability: Hot climate with liquid water

Geography: Single supercontinent with three distinct regions: a southern jungle, an equatorial mountain range surrounding an inland sea, and a northern plain at exceedingly high altitude

Iblis Prime Major Regions

The Gilded Canopy

Predominantly yellow and orange-leafed jungle, home to a unique curative compound, comprising the southern end of the planet’s supercontinent

Terrain Type: Forest (Unique Compound)
Resource: Xenos Ruins (Sustainable): unknown origin
Resource: Ornamental (Minimal): precious metals gathered in small quantities within the leaves of certain plants
Resource: Industrial (Significant): various minerals and compounds with industrial applications
Landmarks: Mount Nalthis, a mountain that rises from deep within the jungle
Native Species: The Emerald Stalker, a vanishing stalker native to the Gilded Canopy
Inhabitants: Humans (Imperial tech-level, at least locally starfaring), in a handful of small cities such as Meridian

The Ring of Fire

An extremely hot mountain range surrounding an inland sea which bisects the continent

Terrain Type: Mountain (Boundary, Extreme Temp)
Resource: Exotic Material (Major): a superstrong, superlight metallic
Landmark: A cave network formed by ancient lava flows
Landmark: The Boiling Brine, an inland sea formed from the collapse of a supervolcano caldera
Native Species: Blunderhoof, a venomous terror with potent toxins
Inhabitants: None

The Cloud Barrens

An expansive plain set at extremely high altitude, north of the Ring of Fire

Terrain Type: Plains (Unusual Location)
Resource: Radioactive (Minimal): unknown, rumored
Resource: Exotic Material (Limited): unkown, rumored
Resource: Industrial (Significant): various minerals and compounds with industrial applications
Resource: Archeotech Cache (Significant): unknown, rumored
Native Species: Kymera, an apex predator and veritable killing machine, the threat of which dominates life on the Barrens
Inhabitants: Eldar (Primitive Clan of Exodites)
Inhabitants: Humans (Pre-Industrial)

The Watchtower (Orbital Hab)

A station in low-orbit over Iblis, populated by humans, who act as sentries for ship traffic and a trade-depot in low orbit. The Watchtower lacks the capability to truly blockade the planet, but can certainly cause headaches for anyone planetside dependent on interstellar commerce.

Disposition: Depends on who you ask, though various opinions circulate around Meridian:

-Leeches who levy an unearned tax on commerce
-Guardians who provide a valuable service to protect commerce
-Weak-willed voidsmen who lack the resolve for life on a dangerous surface
-Pilot aces who ensure there are no outside threats on a planet that has plenty of ways to kill you without outside assistance

Known Contacts: None

Meridian (City)

Located within the Gilded Canopy, Merdian is one of the major human settlements on Iblis Prime with over a hundred thousand inhabitants. Meridian is home to a variety of factions who control various aspects of the city’s operation, as well as the players’ own burgeoning colonial operation.

Teska “Tess” Raitoral, aka The Librarian. The closest thing to a head of state within Meridian. As spymaster of the Sentinels, it’s an open secret around Meridian that she calls many of the shots, though she holds no formal title or office.
The Peacemakers: Euphemistic title of the mercantile co-op that forms the ruling council and represents the formal political power in Meridian. Despite the name, the guilds, companies, and collectives that makeup the Peacemakers all have considerable butcher’s bills.
The Devoted: Religious zealots who offer deific reverence to a man they call The Wanderer, who travels the Cloud Barrens performing miracles. Their descriptions of The Wanderer suggests he could be anything from a charlatan to a daemon to a Living Saint of the God-Emperor.
Techno-gangers: Broad term for the gangs of underworld scum who delve deep into the jungles in search of xenos- and archeotech. They keep the best scores for themselves, fence  or counterfeit any lesser tech they find, and fight amongst themselves (literally and figuratively) to sit atop “The League Table.” Current records don’t elaborate on what the League Table might be.
The Sentinels: A Spartan-like garrison of warriors who protect Meridian. They earn their stripes through tests of survival in the Gilded Canopy, and senior members even carry trophies of Kymera. Far from dumb brutes, they boast an intelligence network under The Librarian that rivals any on the planet, much less in Meridian.


While we created Iblis for Warhammer 40k, it could easily be used in most spacefaring sci-fi settings by swapping out the setting-specific vocabulary, though Warhammer 40k RPGs are decidedly more harsh than in other games.

In addition, there are many blanks left for GMs and players to explore and fill-in.

Plot Hooks

Iblis Prime is designed as an equilibrium for the players to disrupt. In our game, that’s by founding a colony within Meridian in order to usurp, rule the planet, and induct it into the Imperium… all while earning themselves a profit. Whatever plot threads the players pull on should send ripples throughout the other factions, and may uncover more factions they don’t yet know about.

Here are some ideas our group has considered:

  • Fall-in with techno-gangers to level up gear and unite them
  • Bomb the The Peacemakers and claim territory in the ensuing chaos
  • Join the Sentinels to gain access to their intelligence network
  • Twist the Devoted into agents of the Emperor and, therefore, themselves
  • Defeat a Kymera to prove they’re the biggest swinging dicks in town
  • Begin a mining operation of their own and ingratiate yourselves with the Peacemakers

Please let me know in the comments below or on Twitter if you use and adapt Iblis Prime, and how your game plays out.

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