Ideas for "old sewer" dungeon?

[msully4321]

So, during my last session I wound up needing to improvise a whole lot, and my players wound up with a remarkably cliche job of clearing out a path through the "old sewers" of the capital city and then escorting one of the claimants to the imperial throne through, so he can have himself crowned. (The party is actually working for the other claimant, and an ambush is being planned, but that's not really important for this.)

So, they quickly emerged into an underground lake where they encountered an aboleth. That ended that session. Now, I need to plan out the rest of this "old sewer" dungeon. Any ideas?

Note: the old sewers are mostly abandoned sewers from the early days of the city. They are looking for a path from a drainage grate some distance outside the city to the new sewers.

Thanks!

Edit: This is 3.5.
Edit 2: I have 6 level 7 characters.

[RTGoodman]

Well, the short little sample adventure in the back of the Eberron Campaign Setting takes place mostly in an old sewer, so that might be worth taking a look at if you've got the book. The coolest part is a fight that takes place on the walkways on either side of the water in the middle, in a spot where there are something like 4-5 grates/tubes on each side of the whole passage. Every round, one of the grates (1d8 or 1d10 to determine which) opens up, soaking anyone in front of them and potentially bullrushing them off into the water. You could do something like that, but a higher-level version since your players are likely a high level.

Otherwise, check out either the Dungeon Delve book (if you're in 4E) or maybe even Dungeon Master for Dummies, since it has an entire dungeon generator in the back that could be cool.

[RS14]

Off the top of my head: the aboleth had expanded the sewer to form his lake. The original sewers themselves are tiny, cramped, and traversing them requires wading through the muck. Basically an intentional subversion of the spacious sewers of fiction.

Creatures encountered might include mephits (Ooze or Water), a Basilisk (petrification would likely block the channel), and Gibbering Mouthers. If they're still outside the city, consider some environmental hazards---the sewer can be shallow, wide, and open to the air, resulting in slow water but deep muck, quicksand and dead vegetation (and predators lurking in the vegetation. Maybe they find a corpse, if you need a plot hook).

To keep it from being an incredibly linear dungeon crawl, allow various shortcuts. Let them climb out through storm-drains to bypass sections, although their stench may attract unwanted notice, if relevant. At least some unused sections should be high and dry. Possibly erosion will have worn new channels. The walls may be weak, and easily widened. If they have access to Water Breathing, make sure they stumble into other, completely submerged channels, possibly containing more dangerous, organized foes, or simply pockets of accumulated poisonous air.

[Jack_Simth]

So, during my last session I wound up needing to improvise a whole lot, and my players wound up with a remarkably cliche job of clearing out a path through the "old sewers" of the capital city and then escorting one of the claimants to the imperial throne through, so he can have himself crowned. (The party is actually working for the other claimant, and an ambush is being planned, but that's not really important for this.)

So, they quickly emerged into an underground lake where they encountered an aboleth. That ended that session. Now, I need to plan out the rest of this "old sewer" dungeon. Any ideas?

Note: the old sewers are mostly abandoned sewers from the early days of the city. They are looking for a path from a drainage grate some distance outside the city to the new sewers.

Thanks!

Edit: This is 3.5.
Edit 2: I have 6 level 7 characters.

Well, you know why it was built (sewers), when it was built (early days of the city), and what it's primarily used for already (getting sewage out of the city). That actually gets you a lot in and of itself.

You've got decent ideas already posted, but don't forget - there's a reason the mark thinks going through the sewers is a good idea: They're not officially monitored, and basically nobody is willing to chase you down there. Who else would think that useful? Anyone with something to hide - thieves, thugs, murderers, fences, cultists, smugglers, and so on. It's not entirely unreasonable for you to stumble across a cult that has reason to avoid practicing in the light of day, or access to a thieves' guild, or a black market outlet, or what-have-you.

[Seffbasilisk]

Don't forget Oozes. A crucial part of any sewer-adventure.

[wykydtron]

Well here is something that might help a whole lot.

http://www.dandwiki.com/wiki/Sewer_R...ign_Setting%29

Also I think that having cave-ins, sewage backups and broken pipes filling rooms or tunnels the pcs are in would help generate some danger.

[krossbow]

Have them run into a horde of undead rising from the filth due to some undisclosed reason or something; perhaps a necromancer has been using the area for a dumping area for unfit creations?

[Randel]

Turtlefolk ninjas

[LurkerInPlayground]

Off the top of my head: the aboleth had expanded the sewer to form his lake. The original sewers themselves are tiny, cramped, and traversing them requires wading through the muck. Basically an intentional subversion of the spacious sewers of fiction.

Off the top-of-my head, it could be the sewers are a recent construction built atop of some other older pre-existing artificial/natural complex. It's still a giant hole in the ground and it seems to funnel away wastes away just fine. Who cares where it really leads?

[Another_Poet]

Go to the link in my sig and enjoy the wonderful sewer campaign I've been chronicling.

Complete with maps, DCs and encounters (though the encounters will be too low level for you; season to taste).

ap

[LibraryOgre]

Something as powerful as an aboleth is going to control a good chunk of the sewers.

Are these sewers still in use? While they're called the "Old Sewers", is there a "New Sewers" that actually do the day-to-day craphauling for the city? If they're still in use, you're likely to find an otyugh. You might also find were-rats or sun-sensitive undead or humanoids. They might be an alternate pathway for thieves to traverse the city.

Given that the main plot seems to involve the claimant to the throne, I'd concentrate more on things like that, and throw the others in as flavor... maybe running into a band of thieves who are running through the sewer, but don't want a fight, or seeing a warning about an otyugh scratched into a wall.

[Sstoopidtallkid]

'Basic' enounters, ones which have little story impact but are fun.

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• Hiding thieves
• a murderer in the process of disposing of a victim
• diseased water elemental(give it a con-damage attack and make everyone it hits save v. disease)
• Rats. Big ones. Like, advanced, Mineral Warrior, Half-Giant Rats that are each CR 7.
• Alligators
• A cult in hiding
• Kobolds. Just because.

'Story' enounters, ones which will make the PCs use their brains as more than an attack macro

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• Hiding criminals, who have been forced to abandon their families due to persecution in the world above.
• ghost of a murder victim dumped down here
• Extraplanar water creature, come to punish the city for what it has done to this...can you even call it a liquid?
• WereRats who have defended their lair to Tucker-levels.
• A group of half-dragons who are hated and feared by the cityfolk. Of course, they're still desprate enough to eat the PCs if they get a chance.
• A cult in hiding, that has been forced from the surface despite worshipping a basically good god due to their ability to use divine power to find the true heir.
• Kobolds are preparing to invade. The PCs found one of their approxamately 12 entrances to the city(they know this from a prisoner). After they clear the Kobolds out of there, collapse it, and get the City guard to watch it, they find 5 more invasion routes into the sewers. That leaves 6 they have to find in the future, but they have time(searching for invasion routes essentially becomes a 'what do we do for 3 days while the Wizard crafts' activity)

Enviroment effects, things that depend on it being a sewer

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• Toxic fumes
• spells react badly with the enviroment(fireball is hot enough to ignite the area, but Scorching Ray isn't, Lightning bolt breaks through some walls and bounces of of others, some Summoning spells don't work due to the 'hostile enviroment clause). The point is not to hose the players, the Wizard gets Know:Arcane checks to figure this stuff out, but now he has to really think. Ignition and bouncing spells are actually pretty useful, once he applies them.
• Everything is slippery. Take the Grease spell, and apply it to every surface. Plus, any bull-rush is more effective.
• The 'water' is harder to swim in(+2 DC), and the penalties for sinking considerably more severe. Just wading through it increases your Armor Check penalty by one until you can clean your armor(one minute of work, requires help or removing the armor).
• The entire area floods at X o'clock when something happens in the city above. This is a daily occurance, and they can make perception checks to notice animals geting high up, and even the bandits they're fighting run away when the clock strikes. They have to outrace/avoid the water without getting lost, and if they're caught in it, they get slightly seperated and moved very far. Exactly how seperated/far depends on skill checks.
• Certin areas are only accesible through cramped areas, underwater, past grates, things like that. This was designed to move water, not people, and in some cases they can see where to go but not get there.
• When they triumphantly return, having anhiliated a dozen threats to the city, they stink. Beyond belief. They smell so bad they can't get a bath. It costs several platinum for a pig farmer to loan them a trough, and as they leave they see him burn it.

[herrhauptmann]

A good encounter I've run, one that can be adapted to almost anything, is a chase.
The one I used: Chasing someone through a series of alleys. Each intersection, I rolled for teh chasee to see which direction he took, and marked off on my own notes where he was. He had a headstart over the PCs, but they all moved at the same rate. It was awesome as they actually kept catching up with him and losing him.

That can be adapted with a series of criss-crossing sewer junctions.

[msully4321]

Thanks for all the great suggestions!

Things I think I am going to use:

• Sewage elemental
• An otyugh
• Possibly wererats
• A lot of Sstoopidtallkid's environmental things
• A smuggler who could be convinced to show them a quicker path... If they don't report him or kill him and take his stuff.

Most of the encounters the players have had (and will have) so far have been against humanoids with class levels, so throwing them against a bunch of monsters will be a nice change of pace (and easier for me!)

[Atamasama]

You can look up old sourcebooks on Waterdeep (from the Forgotten Realms campaign). It had an infamous sewer system, as detailed in City of Splendors.

Sewers are unclean (duh) and diseases are common, be sure to include the chance for contracting disease just by being down there, especially due to infection if any party members have open wounds.

One cool encounter would be if the party stumbles into an area filled with some sort of eggs (giant spiders maybe?) that begin to hatch if disturbed. Perhaps an area they have to pass through.

[SilverClawShift]

I think it would be crazy to ignore having some kind of "Wererat Lord" who's converted the sewers into some underground mockery of a surface kingdom. Down below, the rats rule supreme.

Complete with new tunnels and expansions created by the were-rat society