So I'm planning on running a game of BC for 4-5 players in a couple of months, and I started writing the story down a few days ago. Here's the basic premise:

The heretics start the campaign in a remote fortress city of a powerful chaos warlord. The city comes under attack by a rival warband of pirates, who manage to strike the city thanks to a man on the inside shutting down the fortress's defense batteries. The raiders are driven back, but manage to get away with both the traitor and a large stash of valuables. More importantly, the ruling warlord feels like he's been humiliated, so he hires the players to join his host in an effort to take revenge on the raiders.

The players will eventually take the fight to the raiders, slay their leader, capture or kill the traitor and recover the stolen property of the warlord. Among the stolen valuables is a piece of a broken, smoky black crystal-like object that seems to be calling for the players. Literally, with a demonic voice, or something like that.

It would begin to appear as though the raiders were after this object, which turns out to be a part of a much larger puzzle. The voice within the broken artefact promises that if the players bring together the scattered pieces of the artefact, it will grant them great power.

This is the problem: I can't come up with what the artefact would actually do once all its pieces are brought together. I figured there could be 5 or 6 of them in total, each located on a different planet or celestial object in the Vortex. It needs to be something relatively big, as many different factions would be after it - including possibly the remnants of the aforementioned raiders and the warlord (once s/he discovers the true nature of the artefact, and that the players have taken it for themselves)

Any suggestions?

I would get rid of the idea that the Warlord would "hire" the party, and instead "select" them for the task, as BC's monetary system is based on acquisition rolls. Basically, at certain points where you're thinking of rewarding them, give them an acquisition roll or three.

As for the Crystal; as a Warp object, it should have a personal effect on the people closest to it. Each piece can be a Compact that the party performs; as the party gathers pieces, the crystal can have effects on them.

Like, when they recover the first piece, maybe they gain some corruption due to the warp-whispers.

The second piece, which fuses to the first, gives them some bonus stat, like d5 to one of choice except Infamy.

The third piece, fusing again, gives them an Infamy boost, like d10 Infamy.

The fourth piece, fusing again, gives them the location of a great wealth (a bit of a side quest that could net the players specialty items they may have been asking for).

The fifth piece, fusing again, gives them political clout; they gain minion(s) and/or a bonus to Fellowship.

The six piece, fusing again and completing the crystal, spawns a greater daemon, come to claim their souls. The initial effect is some kind of paralysis and then a bit of corruption as the crystal explodes and a greater daemon of Slaanesh comes forth.

See, because Slaanesh's number is 6; there were 6 pieces. And the pieces all allude to giving the players their hearts' desires, only to come and claim them.

At least, that's an idea you could use.

Sounds like a very good plan! I wonder though if the players should be given a small incentive alongside the corruption points to really grab their interest? If the players immediately begin to think that the artefact is nothing but trouble, the might just hand it over or try to dispose of it.

Well you could always have the Warlord send them immediately on their next mission, so that they would have to collect the second piece...

Other options include offering an incentive-buy, like, they can purchase the Basic level of any Fellowship skill or the Medicae skill for 100exp instead of the usual 200exp.

Something like that.

Carrot and stick techniques works wonders in RPGs, I too would go with an xp discount on select skills.

I like the idea. An object with a Keeper of Secrets bound into it, which was (somehow) shattered. Due to the way this was done, the daemon can only be released if the crystal is reassembled first.

It's prepared to use it's resources, knowledge and powers to bribe/persuade/compel the heretics (and anyone the heretics need aid from) to acquire it's other fragments.

Also, note that the more fragments they acquire, the more schitzophrenic it's going to get (many fragments of its conciousness in the same vicinity but not yet joined back together).

Once reassembled and free, of course, it will switch to 'sudden but inevitable betrayal' mode. If it had any sense it might make out there are more fragments than there actually are, in order to surprise the players.

Lastly, if you want something interesting to throw in: Who actually bound and divided it? If you want a really out-of-the-box opponent, the whole thing sounds like a most excellent joke for a harlequin troupe to pull off....and they'll be most put out if they become aware of someone attempting to undo their hard work.

Magnus Grendel, I thought of either having it be a lost, anti-xenos civilization or Eldar harlequins.

On the other hand, wouldn't it be more fair to offer the players a small chance of figuring out the daemon's scheme, and take advantage of it by, say, trying to seal it to be used as a weapon when it's released? It's just that the players might feel more than a little bummed out when they find out that all their hard work was for nothing (Or maybe I'm just being soft).

You could remotely map out a dungeon crawl to find each of these pieces. Make a random chart of daemons within the dungeon or battle barge and use the Rogue Trader Bestiary, Mark of the Xeno's or any random creature found in the back of the core rule books. This way, each romp through the dungeon will help your heretics grow in power. Along with the maelifc crystals, you could attune a legacy weapon of their choice found in Tome of Blood. The legacy weapons provide a way of acquiring a powerful weapon of destruction and using it to smite their foes. The legacy weapon will grow in power and there are a couple of penalties for using another weapon instead of the legacy weapon. So main thing flesh your encounters out upon the worlds where they will go and see if legacy weapons are a good fit for your group.

Read Doomstones for WHFRP 1. The powers contained by the stones and the result of fusing them should point you in a good direction for this kind of 'hunt the magic bauble' adventure.

Magnus Grendel, I thought of either having it be a lost, anti-xenos civilization or Eldar harlequins.

On the other hand, wouldn't it be more fair to offer the players a small chance of figuring out the daemon's scheme, and take advantage of it by, say, trying to seal it to be used as a weapon when it's released? It's just that the players might feel more than a little bummed out when they find out that all their hard work was for nothing (Or maybe I'm just being soft).

Of course. The fact that you're going to trigger a localised apocalypse is eminently exploitable if someone sees it coming.

Ideally, "surrending" the fragments to the harlequins who've just near-butchered the heretics and then cheesing it whilst the daemon nom-nom-noms on the succulent eldar souls strikes me as a good idea...

The following post assumes a Slaaneshi daemon-in-a-bottle, but can be adjusted for any contained Daemon, or even any artefact of Chaos.

This is Black Crusade. If they want to ditch the artefact after you give them hints, they can, but BC is also the sort of game where your players could go toe-to-toe with a Keeper of Secrets and win. Don't give them bonus infamy as part of the putting-together-process, excepting normal infamy gains as they complete compacts and do significant things, but make sure that they know that assembling an artefact of Chaos will do great things for their reputation.

Then maybe lay out some hints suggesting it's a trap, if they need them. Since we're talking about a Daemon-in-a-bottle, they might ditch the artefact and run, at which point it may inconveniently show back up in their gear (they only thought they threw it away), or it may start making Daemonic Mastery tests to influence whichever player is in closest contact with it. It may offer secrets and knowledge (group-wide discounts on all Slaaneshi advancements? Yes, please!).

If the players become certain it's a trap, they may get creative and try to acquire a rite of binding, so that they can turn the KoS into a daemon-weapon, or even a daemon-engine. Alternatively, they may say "yup, trap. Let's do this yolo" and put the item together anyway. This, I think, would earn them even more Infamy than putting the artefact together (and accidentally triggering the trap) would have if they had not known, because of the sheer ballsyness involved.

You could also draw it out, arranging side-compacts and semi-related events (raider involvement must be countered, harlequins are getting mixed up and need to be put in their place, a champion of Nurgle wants to get his paws on the artefact so he can sacrifice it to the Plague Father, so on and so forth). At that point, if they gain sufficient infamy and are properly prepared, I could see a creative Slaaneshi or Nurgle player using the artefact to prompt his Daemonic ascension- the first by binding the daemon and bonding to it via ritual, and the second by binding the daemon and sacrificing it, just like the aforemention champion of Nurgle wished to.

At this point, you may even have a conflict of interest in the group. The Nurgle player wants to sacrifice the Daemon, the Slaanesh player wants to bind it to her soul, the Khorne player just wants to chainfist it to death, and the Tzeentch player... well, who knows what the hell the Tzeentch player wants? Drama ensues.

Why does it have to be a chaos artifact?

I like to turn things upside down in my games why not have the soul imprisoned within be of an imperial saint captured and tormented for all eternity? His pleas and promises sound the genuine article as do the rituals that need to be performed but in the end all you do is free him and serevely brown off the gods.

Or the spirit stone of a lost eldar phantom titan maddened by millennia of enduring the pain of being shattered by spiteful slaneeshi cultists who couldn't quite manage to make their captured soulstone into a sacrifice?

Or a broken Jokero communication device linked with it's twin aboard a lost ship full of goodies?

Also decent ideas, but they could dramatically alter the scope of the game. Jokaero devices are unique but rarely understood- or tracked by large organizations, as individual devices rarely get advertisement.

Spirit stones mean more Eldar involvement. Lots of Eldar involvement.

A caged saint means that the AdMini are going to take interest, which means you might face off with the AdSor, possibly with inquisitorial support, or perhaps a particularly faithful Rogue Trader.

However, since we're dealing with themes of Chaos in the scenario so far, I would expect it to be an artefact of Chaos. It may be powered by a Soul Stone or the soul of Drusus himself or what-have-you, but it will still be inherently a thing of Chaos- again, unless OP decides on a change of theme.

to be honest when I read the op's post I immediately thought that this was a reverse view point of citadel of skulls over in rogue trader. That adventure has the trader infiltrate a chaos strong hold with the help of a former lieutenant to steal an ancient computer core they need to find a missing craft world ( I think , it's been a while)

to be honest when I read the op's post I immediately thought that this was a reverse view point of citadel of skulls over in rogue trader. That adventure has the trader infiltrate a chaos strong hold with the help of a former lieutenant to steal an ancient computer core they need to find a missing craft world ( I think , it's been a while)

You're correct. Also, I'm totally stealing this idea. Reversing Fallen Suns (where the PC's actually find a corrupted, lost, craftworld) has so much potential for Black Crusade. :-)

Cheers,

- V.