So, I got this idea for a campaign that starts with the players being sent by an Ordo Xenos Inquisitor to explore an alien ruin somewhere in the Calixis Sector.

This Inquisitor is part of the Tyrantine Cabal.

Yes, this is gonna involve the Tyrant Star.

Now, I have three questions:

1. Are there any canon planets that could have unexplored alien ruins?

2. What Rank should the characters be? I'd rather not have them start at Rank 1.

3. How stupid is my idea?

1. Yes, a few dangerous alien ruins are described in the Radical's Handbook. A few creatures are described in Creature's Anathema that would be nice to throw at them.

2. If you want them to not be useless, then I suggest between Rank 3 and 4, not necessarily powerhouses, but they'll be at the point of not really being pushovers. It also depends on what weapons and armor you've allowed them.

3. Not very, though I don't see why you have the Tyrantine Cabal connection. There aren't explicitly linked monsters with the Tyrant Star beyond the Haarlock Trilogy, and those are specific to their location. It can be just as entertaining investigating an xenos ruin and run screaming from the terrors that lie within.

I've always wanted to do something with the Tyrant Star and the Ordo Xenos.

The Inquisitor that the Acolytes are working under has a theory that the Tyrant Star is connected somehow to a forgotten Xeno race.

The whole Tyrantine Cabal thing is there because I don't want to have some random Ordo Xenos Inquisitor investigating the Tyrant Star.

The issue with that is that you'll have to actually make a connection. The Haarlock trilogy will be your best bet for actual information on the star. Radical's Handbook aslo has the most miscellaneous scraps of information on it as well.

I'll check those out.

I've got this idea that the Tyrant Star is an automated platform of sorts that was created by an unknown Xeno race.

The creators of it are long gone but the star itself is still running.

One more question.

How should I gather the players together?

In previous DH games, it's always been borderline kidnapping but is that necessary?

Well that's more of a personal preference thing, and you can do as you please. It really depends on what kind of game you want to run.

You could easily have them already understand they're acolytes, even know their inquisitor if you want. Understand why they were chosen for this particular mission and so forth. That, or like you said, you can have them forced into it because they're the only ones avaliable that can be taken without arousing suspicion.

If I were you, I'd just have them understand they're following up one of many leads, that's why an acolyte team is going. He doesn't think it will bring up anything important, but still wants someone he knows and trusts investigating it if it actually proves of importance. They should each have a reason why they're working with the ordo xenos as well. that should be handled durring character creation, there are a few alternate ranks that deal with xenos in dark heresy, have them look at those. It wouldn't make much sense for an ordos xenos inquisitor to have an ordo malleus built acolyte with them would it?

For example, if one of them is scum see if he wouldn't mind being from the Cold Trader Guild background, or a xeno-arcanist adept.

How should I gather the players together?

In previous DH games, it's always been borderline kidnapping but is that necessary?

The free sample adventure Edge of Darkness (in the DH page's 'Resources' section- I'm too lazy to set up a link) it is assumed that the PCs were already employed by their Inquisitor in some capacity, but that mission is the first time they have been grouped together as a team .

That's what I did for the group I'm running The Haarlock Trilogy for. Now a new player joined, so I have to figure that out.

Do not try the "kidnapping" thing too often. I did the first Haarlock adventure with my group of players and it was fun. But being kidnapped and waking up without any gear, weapons and ressources was obviously a traumatic experience for them. Since then they try to avoid being captured at any costs. "I will never again loose my precious equipment" - seems to be their motto now.

This attitude makes adventures difficult sometimes. Right now they are in the middle of a battle against overwhelming enemy forces. They started the fight although they had the chance to avoid it by letting themselfes being captured.

We had a break and I still try to figure out what to do. Let them all die - and face the consequences of frustrated players... let them win and this way fuel their attitude of "better fight than loosing my gear"...

Or let them capture a very exciting piece of loot, which in the end turns out to be a hideous chaotic thing. Maybe that cures them...

Okay, thanks.

I'll probably have them be acolytes already.

Another question.

Is having the Star be built by the Old Ones stupid or very stupid?

In my humble opinion yes and very yes. Mentioning big canon names like that can give you headaches if your players know about them out of character. There's an ancient alien race already from the sector that was dangerous enough on its own called the Yu'vath they're a re likely candidate for having built the thing. They also have some fairly powerful corrupted stuff you can throw at your acolytesoo. They're mentioned more in rogue trader though so just look up the name on a wiki for a general idea of what they were like.

Okay, cool.

Yu'vath it is.

Or I could come up with my own species.

-Or, if you want freer reign, you could make it an artifact of the mysterious creators of the Halo Devices (which I believe are supposed to predate the Yu'Vath by a wide margin, iirc).

I believe you're right as well. Haarlock also got ahold of a few of these devices, so it's not impossible that's where he originally heard about the information he did and investigated based on that lead.

The most you hear about them in Dark Heresy at least is the write up in Disciples of the Dark Gods on the Halo devices themselves. They're Insectoid like if I remember.

Cool.

Also, I had this idea that the final part of this campaign would take place inside the Star.

Is that in any way workable?

You can do what you want, you by no means need our permission.

It depends on your interpretation of what the star is. Read Dead Stars, it's the third adventure in the Haarlock Trilogy and deals with it, as well as getting to the thing itself. That's one idea however, you don't need to follow it.

Sorry, it's just that this is my first time running Dark Heresy and I don't want to screw it up.

It's fine. Accept that you will "screw up", your players will destroy your battle plan, and try and rail against your intended story. It's just going to happen. Even the most experienced GM will forget something, or just not have a plan for how the acolytes react to a given situation. Just try and make sure they enjoy themselves, that's the best victory.

Okay, I'll try to remember that.

Also, is there any mentions of what's in the tombs where they found the Halo Devices?

I got this idea of automated defence systems but I don't want to step on any toes.

I don't think there are any hints about what was in those tombs. But as always: you can put whatever you want in those caverns.

Ancient automated defence systems or traps are absolutly ok. Things like that make an adventure more exciting. Lets say: they are the scifi version of our good old fantasy dungeons, where danger lurks behind each corner :-)

Concerning the Tyrant Star: My advise is - don't aim too high. Of course you can build up your story around sector shaking things like the Tyrant Star if you and your players like it. But they make a story very complex. And complexity is not always easy to handle in a roleplaying round.

Personally I don't like my akolytes solving all those ancient secrets of the sector. They are after all just very small henchmen of a sector spanning institution. So I let them find scraps of information about hideous secrets but more for the benefit of the dark and horror feeling of Warhammer 40k. The Tyrant Star stays an unexplicable horror.

But that's only my personal favorite approach to Dark Heresy. You must find your own

The main reason why I'm doing this is that I've always been so captivated by the Tyrant Star.

The mystery of it has always fascinated me.

There's so many unanswered questions about it and nobody else in my gaming group is doing anything with it, so I might as well.

I fully admit that I'm probably overreaching here but **** it, if I'm gonna fail, I'm gonna fail in a blaze of glory.

They purposely left a lot of unanswered questions with the Calaxis Sector's fluff because of that very reason.

Rogue Trader supplements such as the Koronus Bestiary and the Game Master's Kit have details of Yu'vath constructs, warp-infused tech that act as automated defenses.

1. Are there any canon planets that could have unexplored alien ruins?

Right on Scintilla, there's the ruins of (former) Hive Tenebra (Core Rules, p. 299). It's not officially rated as Alien (then again, what is?), but the cause that lead to its destruction might be of non-human nature. The book is explicitly unspecific about the details.

Similarly, it is hinted that Ambulon predates Imperial settlement (Core Rules, p. 296). The book employs the terms »artefact« and »civilization that fell before the foundation of the Imperium«, which both could be interpreted as »xenos«. However, Ambulon, although ancient, is not ruined. In fact, it's a hive crowded with life. There's more of its kind, ruined and decayed, dotted along the steppes of Scintilla. A visionary GM might see a connection between Ambulon, its siblings, xenos origins, and even the Tyrant Star.