For a new campaign I'm going to be running I was planning to have the Acolytes caught up in a shadow civil war between two factions of the Eldar.

I was hoping to brainstorm a few ideas off of the knowledgeable community here.

The first thing I wanted to ask about was the plausibility of my villains.

A large Eldar force was working to secure an Eldar maiden world, having determined that a species of advanced life had evolved or settled there. When they arrived, the species was found extinct, but they found something more significant. Similar to the Eldar of old, this dead species (who were probably advanced psykers) had a god. This Eldar host became convinced that the "shivering god" could protect the Eldar from the forces of chaos. For nearly one thousand years the shivering Eldar have been fighting a secret war with craftworld Miandrothe, hoping to impose the will of their god on their kin.

So, I'm curious if this is a plausible situation within 40k. I know it's mentioned several times in the lore that races with a large presence in the warp can give rise to powerful warp entities with their emotions.

After that I need a bit of help deciding plot points of the secret war. I know that the Shivering Eldar will have been absent for somewhere around 200 years, and their return will be act three of the campaign. But I need to determine where they were in that time.

Additionally, the Miandrothe faction have been using this time to capitalize on the shivering Eldars absence and have been manipulating the Imperium to destroy resources that the shivering Eldar used in the war.

The first act involves the craftworld sponsoring a number of cults on a planet which contains a shivering eldar weapon of some sort. The plan is to make these cults a big enough threat that the imperium declares exterminatus on the planet. Enter the acolytes.

So what sort of cult threat might cause the imperium to fully declare exterminatus?

Thanks in advance for all the help guys!

Sounds reasonably plausible. Question: does the Shivering God actually exist, or is he just a myth the Eldar latched onto? If he does exist, have the Eldar overestimated his capabilities?

Exterminatus-level threats are only those things dangerous enough that sacrificing the entire planet is preferable, so:

• Large-scale Warp incursions
• A very large assembled force of xenos (great military threat if they make it to other worlds) either somehow defenseless against orbital bombardment (i.e., lacking ground-to-orbit capabilities) or so incredibly dangerous that the Navy is willing to lose lots of ships just to be rid of them (the xenos tear apart the ships bombarding them with their self-defense weapons, but are still crushed by the Navy's overwhelming numbers).

Anything else, it seems to me, would be subjected to harsh military action and/or a complete blockade of the planet, but likely not Exterminatus.

Idea: if the Eldar have such great resources that they can create a threat to the Imperium big enough to make them voluntarily destroy one of their own planets just as a means to an end, then they'd probably be a great nuisance to the Imperium themselves (outside the context of the shivering war), and Eldar usually aren't portrayed as such. Instead (or in addition) they might try to impersonate an Inquisitor, Space Marine Chapter Master, or high-ranking Naval officer to order the Exterminatus directly. The Acolytes might get onto their tail when their Inquisitor sends them to check up on the sudden silence of a colleague who was otherwise in regular communication, only to discover that his spire-mansion/ship/safehouse has been raided (the guards cut apart by shuriken weapons), he is himself missing or dead, and the void-safe containing his Inquisitorial credentials is gone...

So what sort of cult threat might cause the imperium to fully declare exterminatus?

If the Shivering God was interfering with the Astronomicon signal (which may be possible if he/she/it has anti-Chaos/warp powers like your Eldar suspect), that might bring a decree of Exterminatus. Not just for interfering with navigation near the world, but for fear that the 'technology' might be replicated somewhere more vital to the Imperium.

Thanks guys, this is useful stuff.

I really like the idea of interference with the Astronomicon, it helps the situation feel like it desperately needs to be stopped, and is a really good reason to declare exterminatus.

I hadn't thought about it before, but the idea of the Eldar having an individual in high office works very well. As far as I'm aware, Eldar have an extremely hard time masking their natural grace to move in a more human manner. So it's unlikely that an actual Eldar is impersonating an admiral or an inquisitor, and more likely that they are manipulating one, which adds a nice level of depth to the story.

and @Drubbles, he's going to be real, but I'm not 100% sure yet what the shivering god is yet. He may actually be a minor deity living in the warp, or possibly a major demon, who is manipulating the Eldar's desire for safety. Alternatively he could be a physical prescence, the psychic might of a single race combined into a single being (which could have been what killed them).

The Eldar could also lure some Tyranids or other dangerous Xenos to the planet and escalate the conflict from behind the scenes (sabotage). That would fit the scheming and cunning nature of the Eldar. That way the planet would be destroyed either way. It could be a whole series of investigations:

1) The Eldar know how Tyranids work and steal some Genestealers from an Inquisition holding cell. The Acolytes have to investigate it and find out who did it. Maybe the Eldar used some mercenaries.

2) The Eldar start a test run and infect some minor planet with the Genestealers. The Acolytes get sent there to investigate the sudden disappearence of communications from the planet.

3) The Eldar infect important persons on the target planet (gouvernor, PDF generals, etc.) and try to use these Genestealers to lure a Tyranid ship to the planet. The Acolytes get sent to the planet to investigate another appearance of Genestealers.

If you don't like Tyranids, just use an Ork Waargh! or a D-Eldar raiding party (or some new Xenos) and switch it around.

Is the name of the god by any chance Sheogorath?

If you want to use Dark Eldar in a non-standard way, you can use them as machiavellian infiltrators that are setting up the cults. You might be able to get the players to assume that Craftworld Eldar and Dark Eldar hate each other (based on other RP settings), but in actuality the Craftworlders are paying a bunch of Dark Eldar to do their dirty skulduggery. One of the points of individual Dark Eldar personalities is that they rarely care about any ideology or legacy, but more about surviving and getting their next fix, so they can easily slot in where-ever.