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Emay Ecks
2017-11-06, 02:48 PM
Hi, I'm currently working on doing a 100% underwater dungeon for my players, and was looking for suggestions.

Recently Sahaugin have been attacking Merfolk settlements and abducting people for evil rituals. The players have been tasked by the Merfolk to find their lair and put a stop to the raids. The party is composed of 5 level 3 characters (Wood Elf Grassland Druid, Half-Orc Bearbarian, Dragonborn Sorc, Elf Colossus Slayer Ranger (UA), and Half-Elf Lore Bard). The party knows a friendly druid who will place Water Breathing on them for free once a day. The Sahuagin are currently hiding out in an abandoned underwater temple in the center of a coral reef.

-Are there any monsters/encounters that I should absolutely use while underwater? Currently planning on Sahuagin and Reef Sharks with an absolutely mandatory encounter with Giant Seahorses (I don't think I'll ever get another chance to use them, so I have to take this opportunity).

-What are some fun traps that Sahuagin would set up? Alternatively, what are some traps in this temple that would still function after many years under the sea?

-Should I have the Merfolk provide the party with weapons that do not suffer disadvantage while underwater for free? Or should I have the party purchase them with their own gold (they definitely have more than enough)?

-How far away do I make the Sahaugin hideout from the players' starting location (Merfolk town)? I do enforce exhaustion rules for lengthy travels (including those that swimming without a swim speed count as double or quadruple time depending on depth). This is mostly to encourage the players to actually investigate where the hideout is instead of searching in random directions or using the Ranger's Primeval Awareness on humanoids and trying searching every location with more than 5 humanoids. There are several ways they can do this (wait around for an attack and follow the sahaugin back, druid/ranger talking to sea creatures for information, talking to merfolk to eliminate false locations that the ranger may have found with Primeval Awareness, and I'm usually really flexible with player ideas and suggestions).

Thank you for your help!

Easy_Lee
2017-11-06, 02:59 PM
For inspiration, what I believe is the first ever underwater dungeon in an MMO. The most terrifying part was the potential to anger large numbers of casters.

https://wiki.project1999.com/Kedge_Keep

Vaz
2017-11-06, 03:05 PM
You could put a timer on the game by offering a dispel magic if you have a counterspeller. It's Con×2 rounds IIRC. You could then give them another way out, through something like a freed Marid.

Hrugner
2017-11-06, 03:31 PM
Be sure to throw in traps that don't function well underwater. It'll help set the scene as a trap filled dungeon and gives players an idea of what sort of traps they may still need to look for. Poison gas traps will still expand and fill an area, but may be a bubble that will float upward more than anything else. dart traps will have disadvantage and poison on them will have been washed away, but you still get darted. Pit traps won't work as traps, but figuring out how to press the pressure plate to trigger one could give them access to lower dungeon segments or corpses of ancient adventurers. Old school "place lit torch here" type secret rooms become much more challenging underwater as well.

Throne12
2017-11-06, 03:31 PM
A hall way with holes large cracks in the walls were a lot or Moray Eels live in. As they making there way throught the hall the eels pop out to take a bite. It's a living trap hall that they have be really clever to get throught or just take hit.

Provo
2017-11-06, 03:33 PM
Oooh, I have been wondering how to do a dungeon like this.

Well the water-breathing is a good idea, but it does remove one of the unique (and potentially fun) challenges of the setting. I would place a few air bubbles throughout the dungeon, and make a boss or mini-boss who can potentially dispel their water breathing (hint at it before the fight).

I would make the weapons highly discounted, and free if they succeed in a high skill check.

Other things I'd consider:

-Water will hinder heavy-armor wearers.

-Use nets and ranged weapons such as tridents against the players.

-Everybody submerged will have resistance to fire. Fire bolt will be weak, but ray of frost may have added effect.

-3D movement. Secret passages or ambushes from above.

-"Chum Trap" The trap doesn't hurt players, but it will attract all the nearby sharks within a few turns.

-Maybe you could put dust of dryness somewhere in the game. It shouldn't be easy to find, but it would be a really interesting tool for the players.

smcmike
2017-11-06, 03:56 PM
brainstorming:

Strong currents might be a fun feature. Doesn’t take much to overcome swimming speed, and require characters to grab on an “climb” the terrain or be swept away.

Silt (or ink) for obscuring vision.

Water temperature and gentler currents maybe can be used to navigate - you feel a surge of cold water from this passageway, etc.

Bubbles from vents on the bottom - They can be used to power traps with their buoyancy, or maybe the characters need to collect air to lift a heavy gait or something.

Emay Ecks
2017-11-06, 05:02 PM
For inspiration, what I believe is the first ever underwater dungeon in an MMO. The most terrifying part was the potential to anger large numbers of casters.

https://wiki.project1999.com/Kedge_Keep

I wasn't even considering the verticality of the dungeon. This is a fantastic opportunity to really take advantage of that.


You could put a timer on the game by offering a dispel magic if you have a counterspeller. It's Con×2 rounds IIRC. You could then give them another way out, through something like a freed Marid.

I don't think I want to remove the party's water breathing. They are level 3, and have no way to counterspell or recast the water breathing by their own power.


Be sure to throw in traps that don't function well underwater. It'll help set the scene as a trap filled dungeon and gives players an idea of what sort of traps they may still need to look for. Poison gas traps will still expand and fill an area, but may be a bubble that will float upward more than anything else. dart traps will have disadvantage and poison on them will have been washed away, but you still get darted. Pit traps won't work as traps, but figuring out how to press the pressure plate to trigger one could give them access to lower dungeon segments or corpses of ancient adventurers. Old school "place lit torch here" type secret rooms become much more challenging underwater as well.

I think some pit traps filled with old adventures would be great. I don't think I'm going to include any dart traps because they just ran a dungeon with a decent amount. I might include some fire based traps, with the mindset that they aren't going to function underwater and deal reduced damage.


A hall way with holes large cracks in the walls were a lot or Moray Eels live in. As they making there way throught the hall the eels pop out to take a bite. It's a living trap hall that they have be really clever to get throught or just take hit.

I love it!


brainstorming:

Strong currents might be a fun feature. Doesn’t take much to overcome swimming speed, and require characters to grab on an “climb” the terrain or be swept away.

Silt (or ink) for obscuring vision.

Water temperature and gentler currents maybe can be used to navigate - you feel a surge of cold water from this passageway, etc.

Bubbles from vents on the bottom - They can be used to power traps with their buoyancy, or maybe the characters need to collect air to lift a heavy gait or something.

I think I might use this as the party spots the temple in the reef. They can try to brave the currents, or slowly try to "climb" the coral, potentially angering sea life that has made the reef it's home (crabs, small carnivorous fish with quipper stats, maybe some poisonous fish). I also love the idea of a very visible spike trap near the ceiling of a room, but swimming near the floor causes a vent to push the players right into the trap.


Oooh, I have been wondering how to do a dungeon like this.

Well the water-breathing is a good idea, but it does remove one of the unique (and potentially fun) challenges of the setting. I would place a few air bubbles throughout the dungeon, and make a boss or mini-boss who can potentially dispel their water breathing (hint at it before the fight).

I would make the weapons highly discounted, and free if they succeed in a high skill check.

Other things I'd consider:

-Water will hinder heavy-armor wearers.

-Use nets and ranged weapons such as tridents against the players.

-Everybody submerged will have resistance to fire. Fire bolt will be weak, but ray of frost may have added effect.

-3D movement. Secret passages or ambushes from above.

-"Chum Trap" The trap doesn't hurt players, but it will attract all the nearby sharks within a few turns.

-Maybe you could put dust of dryness somewhere in the game. It shouldn't be easy to find, but it would be a really interesting tool for the players.

I am definitely going to include a chum trap now. It's perfect for a shark dungeon. I think I might increase the slow on ray of frost, but I'll surprise my players with it if they decide to try it. I definitely need to do more to take advantage of the 3D movement and verticality that being able to swim adds. I like the dust of dryness, but they're in the ocean. I don't think it's going to be effective enough to make any sort of real difference.

Vaz
2017-11-06, 05:14 PM
I don't think I want to remove the party's water breathing. They are level 3, and have no way to counterspell or recast the water breathing by their own power.


5 level 3 had turned into 3 level 5 by that stage, my mistake. Although I'm actually going to use that component in my game. Obligatory Bottle of Air left among the loot.

Kane0
2017-11-06, 05:18 PM
*shudders* Chuul...

You know how some dungeons feature an otyugh, carrion crawler or slimes that function as waste disposal? A Chuul could feasibly play the part in an underwater dungeon. Give it a lair action grapple for extra oomph.

Unoriginal
2017-11-06, 05:18 PM
You could have environmental effects that looks like what happens when a Kraken has a lair in the region.

Nothing need to come out of it, but a fun thing about under the sea adventures is that you can always give the impression a bigger fish is creeping around, hidden by the darkness of the depths.


You could also have a different faction of Sahuagin fighting for the domination of this place. Have them be willing to ally with the PCs for a while if their own skins are on the way, but otherwise be antagonistic.

A good trap for that kind of environment is a room that get both doors locked by huge stones, and then hungry sea snakes and eels invade all the space available, entering by the many small holes in the walls.

Seriously, though, I advise you to take the opportunity and use as many underwater monsters you don't often see used as you want.

Heck, you could even have oozes and other beings not associated with water, but whose presence would be fun show up.

Another trap you could add would be a Brown Mold, that's so cold it'll freeze water around the PCs if they try to swim in the room it is.

stoutstien
2017-11-06, 07:04 PM
I recently sent my party into a system of caverns that which included many flooded chambers. the real fun is imposing disadvantage on sight based on the murky water which while not all that interesting by itself it lead to some very lovecraftian description of what they could make out. some eddies and sharp rocks had my players kissing dry land once they managed to use ropes and light cantrip to navigate out.

MagneticKitty
2017-11-06, 07:11 PM
Was this dungeon built underwater originally or later submerged? If it was built underwater I'd skip the land traps since they don't make sense

Emay Ecks
2017-11-06, 07:34 PM
*shudders* Chuul...

You know how some dungeons feature an otyugh, carrion crawler or slimes that function as waste disposal? A Chuul could feasibly play the part in an underwater dungeon. Give it a lair action grapple for extra oomph.

A single Chuul is definitely making it in as a fun encounter.


You could have environmental effects that looks like what happens when a Kraken has a lair in the region.

Nothing need to come out of it, but a fun thing about under the sea adventures is that you can always give the impression a bigger fish is creeping around, hidden by the darkness of the depths.



This and the comment quoted above got me thinking... I think I know what I want to do big picture with the dungeon now.


I recently sent my party into a system of caverns that which included many flooded chambers. the real fun is imposing disadvantage on sight based on the murky water which while not all that interesting by itself it lead to some very lovecraftian description of what they could make out. some eddies and sharp rocks had my players kissing dry land once they managed to use ropes and light cantrip to navigate out.

Most of my table has darkvision, so it's going to feel really good to deny them the ability to easily see in the dark murky depths.


Was this dungeon built underwater originally or later submerged?

I think I've settled on this being a long abandoned temple, that was built underwater. So this probably means most of the traps were designed with underwater in mind, and there aren't going to be any that have failed after being underwater for many years. The temple's primary purpose will be to imprison a magically-chained Aboleth. The chains prevent it from moving, attacking, or using psychic abilities (including telepathy), but it will still cause regional effects to occur. Sahaugin came to the temple and began worshipping the aboleth as a god and abducting merfolk to sacrifice to it, but they had no way to actually understand what the aboleth says (they share no languages, and the aboleth can no longer use telepathy).

Unoriginal
2017-11-06, 08:13 PM
In that case, don't hesitate using traps that rely more on bones, ivory, coral and the like than on metal.

You might have to decided who imprisoned the Aboleth, though, before designing more of the dungeon.

Also, given it's a trap-filled building meant to keep a very powerful entity, it could be interesting if the Sahuagin hadn't managed to clear up all the rooms yet, meaning that there could be whole section of the temple still filled with its "original" defenders. Fiends, celestials, elementals, mephits, golems, anything goes.


Could also be interesting if, building on my other idea, to have other group of Sahuagin pursue the ones who worship the Aboleth, as they're heretics and troublemakers who have angered the Sahuagin's Shark (Demi)God.


On the subject of the monsters you could use: Sea Flail Snail.

ImproperJustice
2017-11-06, 09:38 PM
This applies to zero G environments as well, but maybe play arpund with the PCs sense of direction and orientation underwater.
Pits and shafts are now tunnels, enemies can approach from odd angles, etc


You’d be suprised a 45degree shift can alter an environment

Kane0
2017-11-06, 09:41 PM
Also don't forget traps that pull/draw/suck creatures into nasty places. Like a riptide or vortex sort of effect, dragging the PCs down a sharp, barnacle encrusted tunnel.

Joe dirt
2017-11-06, 10:58 PM
Enemies... in addition to sea based monsters. i would use undead, as they dont need to breath and u could make them be zombie merfolk to give them under water movement.

Tactics... use zombies as cannon fodder, merfolk could also use dispel magic to destroy the water breathing if u want to be real cruel but i would plan for that contingency by forcing the pc's to be captured and provide some means for their escape. Less cruel tactics is to lure them into an ambush... (remember this is not the pc's normal terrain) i would use murky water to obscure vision and sharks with superior blood trackinģ to find the pc's... nothing scarier in water than enemies u cant see. I would also use nets liberally as this fits a nautical theme

motive... U need a motive these creatures are attacking merfolk. Are they trying to appease an even greater evil? Is it a simple territorial dispute?

Traps... collapsing roofs, areas where walls collapse and can separate the party, wild currents pushing people into rusty spikes

For the record I would force the pc's to use their own cash to fund the rescue but the reward should reimburse them.

Hyde
2017-11-06, 11:48 PM
I really like everything that has been suggested thus far, especially the "bigger fish" thing, which I'd like to expand upon.

Have an encounter with a Kraken or some other enormous monster. The important part is that it shouldn't be able to actually reach the party, and treat it more like a trap than a creature.

"We have to sneak through this hallway, because it's somewhat fragile and the kraken can see into it"
"Oh no, a tentacle broke through that wall and grabbed Dave! we have to get Dave out!"

That sort of thing.

It's not a must, but would really help sell the oppressive... uh.. "atmosphere" that being underwater would generally have. If you've ever played World of Warcraft, the Cataclysm expansion had a zone called Vash'jr that you could check out?

Chugger
2017-11-07, 12:02 AM
For inspiration, what I believe is the first ever underwater dungeon in an MMO. The most terrifying part was the potential to anger large numbers of casters.

https://wiki.project1999.com/Kedge_Keep

Hah I played EQ in '99 - Kedge was so scary. Death was serious in EQ, and it was not fun just swimming down to the place if you were to meet people there and get your water-breathing spell. Things inside could dispel you, so you needed a mage in the party to hand out water breathing stones - you wanted several of those in your inventory. There were little fish that if you killed would explode for big damage - never did figure that one out - except it was a hazard to keep in mind.

When we raided the place you had to be ultra careful. Pets were disabled in there iirc. Everyone was tense because of being in the water and the risk of drowning. The monsters were unique and exotic looking, even with the cheesy graphics - I still miss exploring that place - and you could get _so_ lost til you got the hang of it.

Later on when epics came, we had to go there all the time and it didn't freak me out any more. We were more powerful and we stopped wiping (but it was common to wipe in there in the early daze of the game - corpse recovery was very hard because of the water).

If you're going after an underwater cave system or grotto where sahaugin live, they really should have a well-guarded main gate. Finding a side entrance that is less-well guarded is usually the secret to beating a well-guarded main gate - or going past it invis somehow.

An escaped slave from the lair would be an invaluable source of info for the party, if you wanted to flavor the adventure that way. Instead of going into a place w/ no clue, they'd be going in knowing at least the parts where the slave had access - maybe not the whole lair. And they'd have a sense of what some of the dangers are. This sort of info could get them into the lair through a little-known side entrance. The slave could have you leave a note in a patch of kelp where the slaves are often sent in the day to harvest sea snails and lobsters for the sahaugin that only a slave should find, asking them to create a diversion - so the party can get inside.