As the title says, I am looking to create a campaign set on an agri water world which has an underwater city. However, I am not sure on what the goal and who the antagonist should be. I do want to make it somewhat scary and tense (think of the first Bioshock's introduction) at the same time, but have not written anything like that before. At first I was thinking of making it like a Space Hulk, Alien isolation combination. Players would have to survive against jacked up genestealers (or whatever else is more appropriate) whether it be straight up brute force, tricking it into being flushed into the ocean and even hiding from it.

So, has anyone done something like this before and are there any tips and ideas on what campaign should entail?

If you use 'Stealers (good idea imho), be sure to also use Genestealer Cultists! Few things add more to horror than sudden and gory betrayal at the hands of the "poor survivors" you just rescued.

Or, maybe check out SOMA and think about using Necron tech as an alternative to the Genestealer angle.

Maybe use something that's not really explained, a la the Beast of Solomon from Disciples of the Dark Gods for Dark Heresy. Not straight up combat, but more tense "there's something stalking the party picking them off one by one" and investigation.

Play up the "unknown" angle, don't reveal what it actually is, just a horror lurking in the shadows that is never clearly seen, and gradually picks off the party until only the player characters are left. Comrades and NPC's at the rear of the group disappear without a sound, they hear things and see things move in dark corners and vents (that may or may not be imagined), getting isolated is a death sentence, and let them choose at some point (or several) between digging further into the mystery and evacuating.

Be sure to be liberal with the descriptions of the environment (but try to be sparse with actually giving the players information, try to preserve the mystery), and don't be afraid to punish reckless actions (like running off alone).

My 2 Thrones: I would make the threat an unexpected native xeno race.

I'd start out with the PC's regiment being sent to the water world to drive out some Bad Guys trying to set up a stronghold. When they achieve a fairly easy victory over the Bad Guys and send them fleeing the planet, the bulk of the regiment takes off after them, leaving a small rearguard to hold the planet's only significant land mass (the tip of an underwater mountain) until reinforcements arrive in a few weeks. This should be a cushy assignment...

...But then sentries start to disappear. Every night, something emerges from the waves and takes a few Guardsmen. At first the culprits seem to be dumb animals, but as the guardsmen get better organized to repel the attacks, the creatures adjust tactics. Eventually the PCs realize that the island they are camped on is the top of a massive, ancient underwater city, and the residents- Deep One-like creatures- aren't happy about the 'invaders'...

@ Lynata
I hadn't even considered Genestealer cultist. It could be a good way to cause some moral dilemmas. Are all the survivors infected? Can they be trusted? Do we burn them all with the purifying flames of the Emperor. Maybe the objective is to find a scientist and bring him back, but how can they trust him and know that he isn't about to go crazy and tear them. Maybe they might even start thinking that another is infected and turn on each other. Thankfully, my players don't know all that much about tyranids other than "They nom nom nom planets dead". So it should be a very nice surprise.

@ ExoSaeptus

Exactly what I had in mind. Question though, obviously, I intend for it to be dark and spooky for the most part, but how do I convey light and darkness rule wise? Do i limit there vision? Give them lanterns or torches? Since I do play things in a narrative style, this seems challenging to me. Maybe its time to get a board or something with grid to play on, because it wouldn't be a problem then.

@ Adeptus-B
That was my first idea and I still want to do something like that as well. For the players to reach the city, they will be dropped off at an abandoned outpost, where they will have to find a boat/ferry and travel to an above water structure that will take them down via elevator. However, during the boat ride, some very angry crab-like humanoids would attack them, jumping onto the boat and what not.

Regarding classes and equipment, is there anything I should restrict? I am not going to allow special classes and was only planning on giving them auto guns or lascarbines and maybe one heavy stubber if someone wanted to play a heavy.

Regarding classes and equipment, is there anything I should restrict? I am not going to allow special classes and was only planning on giving them auto guns or lascarbines and maybe one heavy stubber if someone wanted to play a heavy.

Well, if it's an underwater station you might restrict their armaments to combat shotguns with frag shells (plus any small calibre sidearms, if one of your players has looted a stub autopistol or anything), based on lasguns being too hazardous as they could punch through the outer hull. The Heavy could perhaps get a large flamer.

Or you do it like in Aliens and order the Sergeant to confiscate their heavy stubber ammo once the team goes into sensitive areas (close by the hull).

Shotguns could be work and I like the idea of a flamer. My players like to stay as far away from any enemy as possible (except for the one time a sergeant was immediately gutted by an ork nob after stepping off a drop ship), so making them get closer to the scary things should make it more interesting.

Having he sarge restrict heavy ammo would also add to the tension, at the very least for that player.

I'd say dig in with some lovecraft mythos. Particularly Shadow over Innsumouth and The Temple for an underwater part. Not sure what to use for the actual city.

To keep up that tension in dark areas, you could try things like rolling Awareness in secret to see if they notice things and telling them things like "You think you may have seen something moving down that corridor".

If any of the PC's have Paranoia or Light Sleeper, try to play that up, something like this , perhaps.

You could also look at Call of Cthulhu for some inspiration.

Those cards sound like a lot of fun. Since I am starting a new Regiment and the players will be starting with 2d10+1d5 insanity points, I might get to use those even if they dont have those talents.

Never really got into of the Lovecraft stuff. No time like the present I guess.

2d10+1d5 insanity points

Paranoia and hallucinations ahoy!

And those notes are indeed a great idea.

Coincidentally, I've just begun watching "School Live" -- an anime that starts out completely harmless about the average day of four schoolgirls. Twist: it's actually during a zombie apocalypse and the show is presented from the perspective of the most psychologically broken girl who acts as if nothing ever happened, including talking to classmates and teachers who are no longer there.

That's a new level of creepy right there, especially given the stark contrast provided by the cute art style. I could see a similar approach working nicely for any horror-based RPG campaign.

2d10+1d5 insanity points

Paranoia and hallucinations ahoy!

And those notes are indeed a great idea.

Coincidentally, I've just begun watching "School Live" -- an anime that starts out completely harmless about the average day of four schoolgirls. Twist: it's actually during a zombie apocalypse and the show is presented from the perspective of the most psychologically broken girl who acts as if nothing ever happened, including talking to classmates and teachers who are no longer there.

That's a new level of creepy right there, especially given the stark contrast provided by the cute art style. I could see a similar approach working nicely for any horror-based RPG campaign.

Well that is messed up... I think I need to watch this now.

It certainly would make for an interesting campaign.

...the show is presented from the perspective of the most psychologically broken girl who acts as if nothing ever happened, including talking to classmates and teachers who are no longer there .

I love the idea of a Guardsman who has racked up too many Insanity Points talking to a Comrade who died a few sessions ago...

So an important question. Which genestealer stats should I use? I have both the ones from Salvaging Solace and the Deathwatch one from The Emperor Protects.

Its clear that the Auran Genestealer is a LOT stronger than the regular one, but having them be a challenge would be nice. However, I want to have an encounter, where if they take a wrong path, they get swarmed up the wazoo and I dont know how many of those the guardsmen could actually take simultaneously. Are there any other genestealer stats that I could use or would be better?

I thought about adding a Broodlord as a boss, but holy molly, that would be one hell of a fight.

There's also yet another set of Genestealer stats in Dark Heresy 1E Creatures Anathema.

Each of the games has their own narrative theme influencing how powerful the characters are supposed to feel. I'd say you should basically decide whether you want to have Alien 1 or Alien 2 here - for the former, use a single (or very few, dispersed across the station) 'stealers with the stats from Deathwatch, for the latter, use a bunch with the stats from Only War.

I thought about adding a Broodlord as a boss, but holy molly, that would be one hell of a fight.

Perhaps as a "riddle"? Something they're not supposed to take head on, guns blazing, but rather to kill by using the environment. Like, blowing a valve to flood the deck and then triggering a massive electric discharge from the main power lines, all requiring some preparation in multiple locations whilst potentially exposed to attacks.

Maybe it's time to re-watch Deep Star Six?

Really, a horde of 'stealers isn't something a few Guardsmen can really fight effectively (20 wounds, 12 or 6 TB, 4 or 6 AP worth of Natural Armour, and Rending Claws with d10+12 (or 14) damage and Pen 5/7 does not a pushover make, and they'd be utterly terrifying in a group), especially not in cramped quarters and especially not in the an environment with lots of vents and such, where they can bypass the Guard's positions and violently assault them in the rear. These things bring down Terminators with ease, and those are infinitely better armed, armoured, and trained than Guardsmen.

Their best hope (which ain't saying much) would be to lead the 'stealers into an ambush (minefields, corridors rigged to collapse, killboxes, etc), if they really had to fight.

A Broodlord? By Him on Terra, that's just cruel. This thing has 80 Wounds, TB 14, Natural Armour 8, and claws that do d10+16 damage with Pen 9, Razor Sharp, and Tearing, has a 75% chance to dodge any given attack, and absurd movement (like, its movement is 16/32/48/96, about four times that of the average human). *shudders*

After actually reading their stats and not skimming them, I agree with you. It would be too much. I will just make it a group of 4 or 5 should they take that path. Though, that path leads to the exit, so at that point they decided to bug out and run for their lives. I just want to give them a little incentive to run faster or maybe even sacrifice a team mate to slow them down.

Yeah, it was an idea, but when I saw it, I just about had a heart attack. Was not expecting it to be so strong.

Really, a horde of 'stealers isn't something a few Guardsmen can really fight effectively

I dunno; in my experience the Horde rules are very good at making an enemy seem far less terrifying as a group as they'd be individually. They are (much) easier to kill due to not having any Wounds, and whilst their attack itself is absolutely horrible, the quantity of attacks would be very limited.

As such ... I'd say it depends on how many NPCs and Comrades you have to sacrifice?

Really, a horde of 'stealers isn't something a few Guardsmen can really fight effectively

I dunno; in my experience the Horde rules are very good at making an enemy seem far less terrifying as a group as they'd be individually. They are (much) easier to kill due to not having any Wounds, and whilst their attack itself is absolutely horrible, the quantity of attacks would be very limited.

As such ... I'd say it depends on how many NPCs and Comrades you have to sacrifice?

Well, yeah, a Horde would be easier to handle, because those things only really become terrifying with numbers.

But a horde (note the lowercase ) of individual genestealers would be absolute murder.

(note the lowercase )

Gotcha. ^^'

My mind immediately jumped to the Horde rules as the go-to way for handling groups of opponents. Granted, OW also has Formations, but so far I've not had any experience with those (plus I already had my squad houserules for that anyways ).

Formations can be deadly when fighting PCs, and tend to massacre each other when fighting other Formations. I love it.

@Lynata

I guess I need to figure out what would be more intense for the players. Using the brood lord like that would be pretty fun. My players would try to attack it head on, so I would probably need to have it carve up some NPCs or something so they understand what they are dealing with.

I did add the Tarantula Sentry Gun to the regiment for use on later missions, but I was wondering what you think about using it on this one? I know they are REALLY heavy and would be a pain to carry, but I could make a smaller, less potent version, armed with a heavy stubber or twin autoguns?

They would only have one and could be a one use distraction to slow an enemy down, but I feel like that might remove some of the tension.

Edit: I absolutely need to watch that movie. Looks like something right up my alley.

I guess I need to figure out what would be more intense for the players. Using the brood lord like that would be pretty fun. My players would try to attack it head on, so I would probably need to have it carve up some NPCs or something so they understand what they are dealing with.

Give them a glance of the Broodlord from a distance, shredding a platoon or two of Guardsmen. Be sure to play up the fact that it's shrugging off lasfire and heavy bolter shells and butchering Guardsmen by the score.

Should be sufficient incentive to not get into combat with the thing.

Maybe they are called in to reinforce the other platoon with frantic pleas for assistance over the vox, and when they arrive they see the above?

Tarantula isn't really practical without some kind of vehicle to move it from site to site. If they are going to be in a stationary position, I strongly recommend using the SABRE defence platform or emplaced weapons akin to the E-Web turret of Star Wars fame. If you really want to play up horror, though, you want your players to feel like they're armed with wooden sticks. There is no shame in putting the players up against opposition that they can't defeat in a straight up fight, provided you leave the players with an avenue of escape so that when Specialist Timmy gets impaled to the wall, they can flee.

Of course, it depends on what kind of horrific atmosphere you want to set up. For tension, you want opposition that behave like the Dark Eldar. For straight up, in your face horror, then something like a Tyranid Warrior makes a pretty suitably opponent as the players need to flee or fall, likely.

Essentially, how heavily do you want to mess with their heads? I find the best kind of horror comes from the feelings of isolation and not knowing what's in store. My WoD players have been growing increasingly more paranoid in my game because they've convinced themselves that a member of The Gentry is bearing down on them, along with an unscrupulous corporation that they can't hope to match for firepower. They're isolated, don't trust each other, and all have secrets to keep from one another. Only the threat of destruction keeps them unified now that the threat has revealed itself, destroyed their homes, and kidnapped their loved ones.

Different kind of horror again.