Sewer Drain Trap (Advice, Please)

[Drakevarg]

Alright, well as my first subquest, I'm having my PCs wander through a sewer system in order to find an undead-ridden crypt that some urban explorers stumbled upon. (The sewers here are not the "obligatory sewer-themed dungeon", mind you. They're just 5-foot diameter pipes that at high tide have waist-high sewer water in it. Cramped and unpleasant. And full of rats and disease.)

Getting to the point, anyway, these sewers are unsuprisingly filthy. Injesting the water or getting some of the grime in a cut (or simply getting bit by a Dire Rat) will get you rather sick. So as an additional hazard, I've added a few drains that have a chance of smacking you in the head with refuse as you walk by, pretty much gaurenteed to hit you with disease.

I've got the Fortitude DCs for the diseases already, and what I wanted to ask was, what do y'all think I should set for the chance of getting hit while your walking past (I don't want to just do an automatic 'coincidence' when they go by the thing) and what should the Reflex DC to avoid it be?

My current idea is 10% chance of it happening while they walk past and DC 15 avoids.

[blazinghand]

You should give them the option of walking crouched to avoid the swing grates entirely, at the cost of some effectiveness in combat and speed. It could be pretty annoying to have everyone being hit in the head by these grates; or else how would the sewer maintenance staff even fix the place?

[Drakevarg]

No, not swing gates. Just smaller pipes, that, as you walk by, have a chance to fire poo at you. (The pipes are rather slick, since the sewer is in a port city and largely relies on the tides to wash out the grime.)

[blazinghand]

Maybe just make it an attack roll against their AC, if it's not a square-filling effect. Closer to an Arrow Trap than a Pit Trap in that respect. This sounds like a horrible sewer by the way, not in the sense that you poorly designed it, but in the sense that you've designed it like an actual sewer. Ick. There aren't any halflings or gnomes in the group, are there? They'd have to make swim checks

[Drakevarg]

No. Check the link in my sig. The only races available for this campaign are Humans, Elves, Orcs, Half-Orcs, and Half-Elves. I never understood DnD's midget fetish.

Alright, so, Attack Roll they'll almost certaintly be flat footed, and armor would feasibly keep the grime from getting into your cuts/mouth...

Alright, the new question is: What should the chance of it happening at all be, and what should the attack bonus be?

Actually, I think I'll just look up the attack bonus of a CR 1 arrow trap.
EDIT: That'd be a +10 ranged attack. Ouch. Or rather, ew.

But still, chance of happening. Any reccomendations?

[blazinghand]

Well, to keep things interesting you'd want them to have sewage launched at them several times, so make the percent chance of happening high enough (depending on how many of these pipes they pass) that there will be at least 2 sewage attacks over the course of the adventure. So, if there are 20 pipes that they will pass, 10% is good. If they're going to pass something more like 10 pipes, maybe make it a bit more common (like 25%).

[arguskos]

No... I never understood DnD's midget fetish.

Amen sir, amen I say!

Also, I don't really have any advice for you, though it is pretty awesome sounding. Hope ya'll have fun with whatever you decide on doing.

[Drakevarg]

Hrm... truth be told, I should make this sewer bigger. The way it's drawn out so far, they'd only pass one drain on the way to their destination. And a secret crypt wouldn't stay secret for long if it was only a few hundred feet from the nearest manhole...

Why is all this work simultaniously incredibly stressful and yet incredibly enteraining?

[blazinghand]

One way to get around that would be to have some sort of secret doors that only the PCs know about (through a map or a contact) or only the PCs can find (Rogue, Elf or Dwarf).

[Drakevarg]

Heh heh heh... can sewer drains flank you? Highly improbable to have both of them go off simultaniously, but still... I am so mean.

[Mr. Mud]

Heh heh heh... can sewer drains flank you? Highly improbable to have both of them go off simultaniously, but still... I am so mean.

Hmm... Yes. THeoretically at least, since you'd be to occupied with Drain A then B ...

Plumbing flank? You cruel bastard .

[blazinghand]

Heh heh heh... can sewer drains flank you? Highly improbable to have both of them go off simultaniously, but still... I am so mean.

I'd say "no" since they don't threaten squares with melee attacks. It's more like a ranged attack at point blank range.

Edit: SEWAGE SNEAK ATTACK!

[Drakevarg]

Bah. Rule of Cool. If it happens, I'm flanking their sorry asses. And then I will laugh.

Also, there are two diseases present in these sewers, Filth Fever and Blinding Sickness. Should I have a seperate Fort Save for each one, or should I say beating the tougher disease automatically beats both?

[Mr. Mud]

Also, there are two diseases present in these sewers, Filth Fever and Blinding Sickness. Should I have a seperate Fort Save for each one, or should I say beating the tougher disease automatically beats both?

Beats both, I think... but not right away. Maybe an hour or two later? Depending on how harsh these are, maybe a few rounds later...

[Another_Poet]

My current idea is 10% chance of it happening while they walk past and DC 15 avoids.

I think this works fine, and it is definitely a Ref save to avoid rather than an attack roll.

Another way you could do it would be to roll on a weather chart. Let's say there is a 30% chance of rain. If you roll 1-30 on a D%, then every standpipe and storm sewer in the tunnel will be dumping on them.... basically they'll have to figure out a way to try to avoid the dirty water every 10-30' or so. Expect PCs to ask about using a Tumble check (Acrobatics in Pathfinder) or using a shield as an umbella. My PCs would also consider just plugging every one of them with some kind of blockage before moving past it. They would also point out that the 0-level spell Prestidigitation can clean people up, and ask if an immediate magical cleaning can avoid the fort save (or at least give a bonus on it).

The advantage of basing the % chance on rainfall is that, in addition to having an excuse to spray your PCs with sewage, you also can floo the sewers if they don't complete their mission and leave within x hours.

By the way, feel free to click the link in my signature for lots more sewer-themed ideas.... we've gone through 3 levels of sewer crawl now and my players still aren't sick of it :)

ap

[Drakevarg]

Well for starters, this isn't a storm sewer. It's a crap sewer. Trying to keep the streets dry in a city built right next to the ocean is kind of futile.

As for it being a Ref save an not an attack roll... if it were a pit, something falling from above, or spears or somesuch coming in from the side, I'd call that a Ref save, since its an AoE effect and all you have to do is not be withing the "A" part of the equation. This is... a disease-ridden projectile being flung at high velocity from a heavily lubricated pipe. Really, the arrow trap is the closest analog I can think of.

As for the chance of rain flooding these sewers... highly unlikely. They flow directly into the ocean, and the highest the water level ever gets from that is about waist-hieght. Even so... I could make it so they have to finish within X hours or they get to walk through waist-high sewage... basically meaning any unprotected cuts from the waist down get a chance to be infected with Filth Fever...

Y'know... maybe I should make them do periodic balance checks. Waste matter is not exactly the most stable of foundations...

[Kylarra]

I'm kind of thinking save as well, since, unlike an arrow trap, this isn't a mechanically triggered trap spec'd to aim at the triggering target. This is a random event occuring. It's not aiming for you per se, you just need to get out of the way.

[Drakevarg]

K... lemme try to coherentize it all:

Sewer Drain
10% Chance
Reflex DC 15 Avoids
If failure,
Fortitude DC 12 Avoids Filth Fever
Fortitude DC 16 Avoids Blinding Sickness

Sewers Themselves
Either Periodic (Every twenty feet or so.) or at specific locations.
Balance DC 15 Avoids
Failure causes you to slip and fall.
During High Tide (3 AM to 3 PM), fall knocks you underwater.
While in water, Fortitude DC 16 Avoids Blinding Sickness.
Contact with water or pipe surface with unprotected wounds at any point,
Fortitude DC 12 Avoids Filth Fever (Plus Blinding Sickness for wounds below the waist in high tide.)

FYI... this is a level 1 campaign... and haven't even brought up the mention of Dire Rats.

[Kylarra]

For a level 1 campaign, this seems kind of ridiculous.

[Mr. Mud]

Is there a check to disable the pipe/clog it? As a player that's the first thing I'd do so be ready for that... .

[Another_Poet]

Well for starters, this isn't a storm sewer. It's a crap sewer. Trying to keep the streets dry in a city built right next to the ocean is kind of futile.

...


As for the chance of rain flooding these sewers... highly unlikely. They flow directly into the ocean, and the highest the water level ever gets from that is about waist-hieght.

Umm, well, let me put it this way. In modern times, using the very best technology and requiring everything to be reviewed and stamped by engineers, storm sewers do overflow into crap sewers. Heavy rain completely floods the storm sewers, backing them up onto the streets (the large puddles you see in city streets during very heavy downpour). When this happens the city/county allows the storm sewers to be diverted into the sanitary sewers, often forcing semi-treated or untreated sewage into the local river/lake/ocean. In fact, this sudden release of semi-treated sewage is one of the most contentious environmental issues surrounding modern sewerage and the expansion of urban areas.

Being next to an ocean has nothing to do with this. The flooding of sewers has to do with the amount of water going in, not where the water is being sent.

The crossover of storm sewers and "crap" sewers is a design choice, and again has nothing to do with location. Partly combining the two is both more practical (as it allows the city to avoid backed-up storm sewers during flash floods) and a money saver (as otherwise you are bulding two completely separate sewerage systems).

Medieval and ancient sewers were virtually always combined stormwater-and-sewage systems, and were virtually never capable of handling massive downpours without flooding and backing up.

Of course, your fantasy sewer is neither a modern nor a medieval sewer; it's yours to design as you please. But you said you were going for more of a "real sewer" feel and you seem to want some believability here. In that case, your fantasy sewer will probably carry stormwater as well as feces. And it will flood in the rain.

For ideas or just general fun reading you might check out www.sewerhistory.org

ap

[Random832]

Medieval and ancient sewers were virtually always combined stormwater-and-sewage systems, and were virtually never capable of handling massive downpours without flooding and backing up.

Doubly so since in medieval times people were okay with letting the crap sewers drain into the river/ocean anyway, which is something we generally try (not always successfully) to avoid these days (thus why modern sewers are usually at least partially separated between the two uses)