Advice request for high level dungeons and traps

[Face_P0lluti0n]

Good afternoon all,

For the first time in my long-running political/intrigue campaign, my PCs have saw fit to go find a dungeon of great legend in the campaign world, in the hopes of finding a unique magic item to help resolve their current predicament. Since the party usually doesn't do this, I'm aiming to make this dungeon challenging and memorable.

However, my PCs are 15th level and the optimization skill level is pretty high. Ethereal plane access, Passwall, Wild Shaping, Trapfinding with a high Perception bonus, Greater Teleporting, being undetectable to various senses, True Seeing, etc etc, are all on the table. If a 15th level character can theoretically do it, my players have probably thought of it.

So I'm just wondering if anyone has, or could point me toward, any collected advice, optimization handbooks, products, etc, that detail the sorts of traps, dungeon traits, or techniques a GM can use to create sufficiently challenging dungeon crawls at this level. Since this is an intrigue campaign, I'm pretty familiar with how an intelligent adversary might counter 15th level PCs, but I'm not entirely sure how a *place* can give the PCs a challenge.

Any advice or references would be helpful.

Thanks!

[Chuck Mount]

Make everything fairly low level compared to them and stick the item in a "magic dead" dungeon. No magic functions inside. No spell casting, no teleport, no planer travel, no invisibility. That should be tough enough for them and since the monsters will be a relatively lower level than they are used to, the encounters should still be a challenge. Fill it with undead and say that only necromantic magic will work because it's an old cult temple dedicated to a deity of undeath. Just don't put any incorporeal undead in there. That would be a dick move with no magic weapons. LOL

[Pizza Lord]

The dungeon was built coterminuously within an ethereal mountain or large chunk of ethereal stone. Not solid, alot of the rooms and chambers mirror each other but there are places where passages are blocked by ethereal stone (or someone shifted to the ethereal and cast some walls of stone. This won't impede normal travel but it does mean that at certain points PCs with force effects, like shield, mage armor, or bracers of armor will have to remove or lower and recast them to proceed. It also means a canny room inhabitant can be standing in a section blocked by an ethereal wall which won't affect normal attacks but will block any force attacks, like magic missiles.

True seeing or see invisibility will reveal these so it isn't unfair since you mentioned the PCs have these available. Also, the PCs can teleport past these if they don't want recast their shields, but then they're still burning resources

The ethereal stone also allows the dungeon owners to keep ethereal beasts within certain locations. I kind of like having an ethereal gelatinuous cube in one room for a boss fight. It can sense into Material plane and will ooze over targets (can't hurt them and can't do this with people surrounded by force effects) but if they do put one up while it's around them they'll have trouble getting free. Also, it will soak any magic missiles that try to pass it, so even if it's surrounding the bad guy it's like a damage shield for force effects. Even if they damage it enough to kill it, its body will still block those attacks and ]'s with force effects may not be able to move close enough to melee a foe standing within it.

[Ring_of_Gyges]

Argon!

The lower level of the dungeon is flooded with argon gas. When the party go down there they'll be fine until they keel over unconscious.

They won't see it or smell it, it is colorless and odorless. It isn't magical, so doesn't ping to detect magic. It isn't a poison (it is chemically inert) so no ping there. It is heavier than air so it will stay down there.

As soon as the party enter the lower level they'll be breathing argon, not oxygen and suffocating without knowing it. The body doesn't have any panic reaction to breathing argon, it thinks it is breathing in and out normally. What makes argon leaks so dangerous in real life is that your first indication that anything is wrong is that you black out, then you're unconscious in a pool of not-oxygen and you die.

The lich who lives down there doesn't mind one bit.

[SmiloDan]

Wine!

Flood a chamber with wine instead of water; water breathing spells don't work on wine.

Trap Idea:

I recently had an idea for a pit trap that had hunting traps at the bottom of it instead of spikes; if you fail a Reflex save, you get hit by 1d4 hunting traps, which pin 1d4 limbs. Then wine starts pouring in, threatening to drown the PCs restrained on the bottom of the pit by the hunting traps.

Magic Dead Zones always seem like cheating to me. No offense Chuck Mount. Especially in an intrigue-based campaign, the PCs might never get a chance to use their big guns. Let them shine in this special dungeon.

Just base the traps on 8th and 9th level spells. Not 8th or 9th level spells--8th AND 9th level spells! Like a major curse that gives them fire vulnerability combined with a meteor swarm!

Require multiple checks to disable the traps. For example, maybe a rune has to be dispelled or disabled in 4 different corners of the room--and they regenerate in 1d4 rounds. Also, each rune has its own golem guarding it.

Design the encounters to play to your PCs' specific strengths and weaknesses. If you don't want them to spam a bunch of powerful spells at once, put a time limit on the dungeon, then fill it with lots medium to hard encounters. If they need to stop and rest, everything resets--and adjusts their tactics to counter what the PCs have already demonstrated.

Make traps encounters and not just a skill check or saving throw, with some healing afterwards if you fail. If you have a hallway full of whirling blades, allow an Knowledge engineering check to grant a +5 bonus to the Reflex saving throws against the blades. Have the damage the blades cause ramp up as they speed up: 6d6 the first round, then +6d6 each round thereafter, up to 18d6 per round. Also, have a way to break the trap, so as it takes damage, it also causes less damage. The fighter should be able overcome the trap by breaking it, the wizard should be able to overcome the trap by dispelling it, the rogue should be able to overcome the trap by disarming it, and the cleric can also try dispelling it.

I've recently become enamored with devourers. They're CR 11, so 4 to 8 of them would work well against a CR 15 party. They're surprisingly versatile, so each one can fight differently.

If a trap is full of undead minions, allow a Knowledge religion check to determine that displaying a specific unholy symbol will allow safe passage. Or something similar with Knowledge planes, nature, or dungeoneering with demons, fey, or aberrations, respectively.

You can also use actual puzzles that require actual deduction to solve, not just a Knowledge arcana check.

I just read a lot of 5th Edition materials: Tomb of Annihilation and Xanathar's Guide to Everything, so I've been really into traps and trap design lately.

[JDLPF]

Illusions are a great 'gotcha' moment, provided you set them up properly. Magic Aura to negate illusion auras are a must for any smart party using Detect Magic. An oldie but a goodie is an illusion of a floor over a pit filled with something nasty. Even worse is setting up the group for a hard fail by actively anticipating illusions. For example, a high DC symbol trap behind an illusion of a wall can ruin a group, especially if added into an encounter where the enemy is keyed to ignore the spell when it's triggered.

Don't be afraid to use custom magic spell creation rules too. For example, on one occasion I created a variant Stone to Flesh spell that gave a temple's unholy chamber a wall around its core that was considered both a creature and an object for the purpose of teleportation inside, passwall, earthglide and the like. Prevents the group from bypassing the entire dungeon with a single spell.

Extraplanar adventures are a great way to mix up puzzles and encounters. Perhaps part of the dungeon passes through the Plane of Shadow. The Tide of Honor adventure did a great maze puzzle that uses the fact colors are all black and white on the Plane of Shadow to create a great twist in solving the correct path to take. Perhaps the dungeon passes through one of the elemental planes instead. The dungeon's been built around a locus of portals between different planes. Perhaps the dungeon itself is intelligent, and malevolently cruel to boot. A genius loci that is in service to the big bad, actively changing its own structure and hindering the group.

Haunts are a great alternative to typical traps when they're no longer a challenge to your group. Instead of a straight Disable Device check, there's a trick or theme to each required to avoid the nasty effects. Detecting them might not key off Perception too, instead using some other esoteric skill like Heal or Knowledge (Engineering). High level ones might be capable of a TPK if you're not careful, so tread lightly.

One dungeon I created contained elemental traps in key corridors, controlled by a puzzle pad. I used a web page for a Lights Out puzzle, set up a touch-screen phone with a partially solved puzzle, then when the group found the puzzle, put the phone on the table and told them to solve it. Every attempt took a move action, and there was constant danger whilst trying to solve the puzzle. Quite a memorable encounter! I'd also planned a boss room where the puzzle actually activated based on which squares the group stood on in the room (requiring Acrobatics to jump to specific tiles etc.) but ended up never using it. Hopefully someone else gets to do it instead!

[Matthew Downie]

The dungeon's 'rooms' could be linked by a series of teleport gates / traps. So a walk-through-walls spell doesn't help, because the next room could be anywhere, and the walls around you are a mile of solid rock.

[Matthew Downie]

JDLPF wrote:

Illusions are a great 'gotcha' moment, provided you set them up properly. Magic Aura to negate illusion auras are a must for any smart party using Detect Magic.

At this level, True Seeing is probably pretty easy to acquire.

[JDLPF]

Matthew Downie wrote:

JDLPF wrote:

Illusions are a great 'gotcha' moment, provided you set them up properly. Magic Aura to negate illusion auras are a must for any smart party using Detect Magic.

At this level, True Seeing is probably pretty easy to acquire.

Thus the double-gotcha by sticking a symbol trap behind an illusion. Or a creature with a gaze attack, or something else nasty based on sight.

[J4RH34D]

I have always had a bizarre Idea I really wanted to create.
The dungeon contains an artifact that does one thing, and is tied to the dungeon. Removing it breaks the effect.
This effect is that it creates a time loop. If the entire party dies they end up back in the first room exactly as when they first entered the dungeon.

The entire Dungeon runs on a timetable, with events happening a certain number of rounds after they enter.
Many of the encounters are designed to be significantly more powerful than the party.
They are supposed to die as they map the dungeon.

There is a way to make it through. There are multiple ways in fact. But the chances of getting it right first time are very very very low.

The dungeon is not designed to kill, as the party can easily leave the time loop, back to just after them first entering the dungeon. It is designed to test, to be difficult, to make sure that whoever gets the artifact (which does whatever you want it to do as well as powering the dungeon) is actually worthy of getting it.

If you want to make it a bit more interesting you can add a level of randomisation to the timetable with dice rolls.

"A rumble is heard 12+1d4 rounds after the pcs enter"
"6+1d6 rounds after the rumble the golem in room XX awakens"
Etc

[SmiloDan]

JDLPF wrote:

Matthew Downie wrote:

JDLPF wrote:

Illusions are a great 'gotcha' moment, provided you set them up properly. Magic Aura to negate illusion auras are a must for any smart party using Detect Magic.

At this level, True Seeing is probably pretty easy to acquire.

Thus the double-gotcha by sticking a symbol trap behind an illusion. Or a creature with a gaze attack, or something else nasty based on sight.

Mesmerist Medusa?

Something that has permanent greater invisibility but a curse that blinds anything that sees it. So a PC casts see invisibility or true seeing and then goes blind. Oops!

[Matthew Downie]

I have a less extreme 'gotcha' technique with 'invisible fog'. Anyone who can see the invisible can't see anything more than 5 feet away.

[Calnar]

I prefer theme, so I would look at what is the legend of the place and who built it. You say they have heard of the dungeon before. What was the story, don't be bound by it, but it should give the flavor of what to expect.

Religious order good or evil, well someone likely placed a Forbiddance spells over the whole enclosure, can't have those pesky mage's popping in and out meddling with their religious relics. This shuts down planar travel including etherealness and teleportation.

If it's a wizard he knows how other magic users think. Maybe he has incorporeal guardians bound to that spot in the ethereal plane. Maybe he has a Ghost siphon that can shift anything ethereal to a certain location in the tunnel.

Teleportation traps are also a thing. Go to d20pfsrd.com and look them up. Similar to the ghost siphon I described Maybe the wizard would have a ghost siphon and a teleportation trap over the whole area. Using one spell will shift you to one room and using the other will shift you to the other room.

Add a Guards and Wards spell for fog and confusion effects with narrow hallways that don't follow a grid, but move up and down or loop back on themselves.

If someone royal built the dungeon, why? If to protect something they may well have payed for all of the above and more. High Level Spell casters with time, money, and access to permanecy spells can seal up most areas pretty well.

You could also have the dungeon's entrance cross into a demiplane or 3. That will limit the effects of the above spells especially if the transitions are in an area of Fog from those guards and wards spells. Then attempts to go around will lead to confusion and if some characters follow the normal path then

Maybe the item they seek is easy enough to get to but if it's an artifact maybe it can only be removed from its resting place if certain trials are passed. Avoiding the trials allows the magic item to transport back to its resting place.

Also if you do any of the above, remember to give your players places to shine. If they can pass some skill test or disarm some traps on the way great, they'll feel like their patience in building these characters is paying off.

Lastly remember anything they can do, so can the villains. Why not a teleporting wise cracking guardian who holds the magic item and keeps popping around the dungeon taunting the party.

[SmiloDan]

I like the idea of the teleporting wise cracking guardian popping in and out, harassing the PCs. And the challenge is to lock down sections of the dungeon so he can only teleport into one room.