High level dungeons

[heavyfuel]

Is it realistically possible to challenge high-level adventurers with dungeons? Likely.

However, the conventional hidden doors and magical traps simply will not do. What good is an adamantine gate when the Fighter can smash it in a single round? What purpose serves the deadly pit when the Druid can summon a creature for safe passage without even missing the spell slot?

So - without resorting to Antimagic Fields - what are some things we can do to challenge players past ECL 11?

[Uncle Pine]

Themes go a long way keeping dungeon crawls interesting. The same dungeon but set in the elemental plane of fire with sickstone lava pools (http://www.giantitp.com/forums/showthread.php?454907-Poison-lava) can be a LOT of fun.

[Karl Aegis]

It depends on what optimization level you're at. Do builds matter? Are resources being expended?

[Elkad]

Rule 1 of static obstacles. They are useless if they aren't defended. 1st level commoners can get by a pit too, it just takes longer to shovel it full of dirt by hand.

Make that door out of Riverine?
Or at least cast Hardening (http://www.d20srd.org/srd/divine/spells/hardening.htm)on the Adamantine version, and put Symbols on it, and a Magic Mouth that yells "Ow, stop it!" when someone hits it, and a triggered-every-round Make Whole (http://www.d20srd.org/srd/spells/makeWhole.htm) effect. And you still need rule1.

[Nifft]

At high levels, the deterrence factor of the traps & guards has nothing to do with the direct threat posed by the traps & guards, rather what you should fear is their ability to alert the Inter-Dimensional Strike Team which is now inbound to your location. How many rounds do you have until they get alerted and come looking for you?

High-level D&D can play out like mid-level Shadowrun, and that can be awesome.

[death390]

if i remember right there is a spell that pull teleportation spells to a set location if a teleport is targeted in its area? AFB so can't check. that negates TP effects without AMF.

[Tvtyrant]

Is it realistically possible to challenge high-level adventurers with dungeons? Likely.

However, the conventional hidden doors and magical traps simply will not do. What good is an adamantine gate when the Fighter can smash it in a single round? What purpose serves the deadly pit when the Druid can summon a creature for safe passage without even missing the spell slot?

So - without resorting to Antimagic Fields - what are some things we can do to challenge players past ECL 11?

A high level dungeon is probably guarding an artifact or something of equal value.

1. There are lots of alarms. The dungeon has a threat level based on how deep the alarm is, so if you trip a 1st level alarm you get swarmed by effigies while an end game alarm triggers agreements with fiends, dragons and other high end monsters. Wherever you are, the administration starts keeping tabs on you with scrying.

2. Traps are layered. A room with Invisible Stalkers in it also has Invisible Spell Explosive Runes coating the walls, so the natural response gets you killed.

3. There is an active administration that won't let you rest. If the party makes a Rope Trick to rest in the admins summon a bunch of monsters then dispel the Rope Trick.

4. You can't teleport in or out of any room except one, which is keyed to the admins and is so dangerous you would die instantly if you entered without a key.

[heavyfuel]

Themes go a long way keeping dungeon crawls interesting. The same dungeon but set in the elemental plane of fire with sickstone lava pools (http://www.giantitp.com/forums/showthread.php?454907-Poison-lava) can be a LOT of fun.

Never heard of sickstone. Where can I find more info on it?


It depends on what optimization level you're at. Do builds matter? Are resources being expended?

This is for an upcoming campaign that's going to start in a few months still.

I don't know what builds players will have, but this thread is more for general tips than anything too specific.


Rule 1 of static obstacles. They are useless if they aren't defended. 1st level commoners can get by a pit too, it just takes longer to shovel it full of dirt by hand.

Make that door out of Riverine?
Or at least cast Hardening (http://www.d20srd.org/srd/divine/spells/hardening.htm)on the Adamantine version, and put Symbols on it, and a Magic Mouth that yells "Ow, stop it!" when someone hits it, and a triggered-every-round Make Whole (http://www.d20srd.org/srd/spells/makeWhole.htm) effect. And you still need rule1.

Good point about not leaving stuff unprotected.


At high levels, the deterrence factor of the traps & guards has nothing to do with the direct threat posed by the traps & guards, rather what you should fear is their ability to alert the Inter-Dimensional Strike Team which is now inbound to your location. How many rounds do you have until they get alerted and come looking for you?

High-level D&D can play out like mid-level Shadowrun, and that can be awesome.

I indeed thought of that. I just hope it doesn't get too repetitive, having enemies use scry-and-die tactics on players every time they activate a trap could get boring soon.

And the last line reeeeally makes me want to play Shadowrun. People say it's awesome, but I never had someone IRL want to play it.


if i remember right there is a spell that pull teleportation spells to a set location if a teleport is targeted in its area? AFB so can't check. that negates TP effects without AMF.

Interesting. A quick search reveled a psionic power Divert Teleportation, but it has a Will save so it's not very good.

(Greater) Anticipate Teleportation is also useful, even if the affected area is small.

If you remember the spell, it might be of great help.


A high level dungeon is probably guarding an artifact or something of equal value.

1. There are lots of alarms. The dungeon has a threat level based on how deep the alarm is, so if you trip a 1st level alarm you get swarmed by effigies while an end game alarm triggers agreements with fiends, dragons and other high end monsters. Wherever you are, the administration starts keeping tabs on you with scrying.

2. Traps are layered. A room with Invisible Stalkers in it also has Invisible Spell Explosive Runes coating the walls, so the natural response gets you killed.

3. There is an active administration that won't let you rest. If the party makes a Rope Trick to rest in the admins summon a bunch of monsters then dispel the Rope Trick.

4. You can't teleport in or out of any room except one, which is keyed to the admins and is so dangerous you would die instantly if you entered without a key.

Not necessarily. A high level dungeon can be a Dragon's Lair or Mage's Private Sanctum.

1. Alarms are a given, but they're easily detectable (even if hard to avoid)

2. That's a very liberal definition of the word "reading". I'd say the caster wouldn't read any runes when he's concerned with the existence of multiple outsiders. But I see your point.

3. Good tip on stopping 15 min adventuring days.

4. How would go about key-ing a room to someone by RAW?

[Tvtyrant]

Seperate Glyphs of Warding on each square of the room with "not holding a key". The square you teleport onto has a Greater Glyph with Forceful Hand on it. This shoves the teleportee over a bunch of the glyphs, which can have whatever you want on them.

Also multiple symbols of X with the the same keyed restriction. Note that symbol of X spells only work if someone looks at them, so the invisibld symbol of death trick also functions.

Hallow can also be keyed to grant Protection from X, and you can key that to the same key holding. The room is not just filled with hundreds of traps that go off when you enter, it is filled with acid.

[Palanan]

Originally Posted by heavyfuel
Never heard of sickstone. Where can I find more info on it?

Uncle Pine linked to a thread that takes you right to it. Sickstone is described in the spell Transmute Rock to Sickstone.

Note that this is technically 3.0 material, since the web article (http://archive.wizards.com/default.asp?x=dnd/fw/20021025a) is from October 2002.

[flappeercraft]

Something that you will have to do is have a counter for AMF as it would disable most alarms and or traps. My choice for the trap would be making the roof of hallways be layered by 8,000lb stone slabs exactly 10ft above the average medium creature and not making them be part of the building itself but actually the reason they are up is hidden immovable rods (paint over the rods with grey paint or something). That way if they activate AMF they will get a couple thousand pounds of rocks falling on them.

[heavyfuel]

Seperate Glyphs of Warding on each square of the room with "not holding a key". The square you teleport onto has a Greater Glyph with Forceful Hand on it. This shoves the teleportee over a bunch of the glyphs, which can have whatever you want on them.

Also multiple symbols of X with the the same keyed restriction. Note that symbol of X spells only work if someone looks at them, so the invisibld symbol of death trick also functions.

Hallow can also be keyed to grant Protection from X, and you can key that to the same key holding. The room is not just filled with hundreds of traps that go off when you enter, it is filled with acid.

Nice concept. I'd be worried about paying the 200gp cost for literally every square in a dungeon though...


Uncle Pine linked to a thread that takes you right to it. Sickstone is described in the spell Transmute Rock to Sickstone.

Note that this is technically 3.0 material, since the web article (http://archive.wizards.com/default.asp?x=dnd/fw/20021025a) is from October 2002.

I'll be honest and say that while I had opened the article I assumed the spell simply said "works like transmute rock to mud but sickstone instead of mud" :smallbiggrin:

Honestly though, it's a pretty terrible spell. A lv 7 spell that's foiled by Suspend Disease, a lv 1 spell for Clerics, Druids, and even Wizards isn't something I'd consider a threat. And people usually have a few scrolls of it since they're so cheap.

[heavyfuel]

Something that you will have to do is have a counter for AMF as it would disable most alarms and or traps. My choice for the trap would be making the roof of hallways be layered by 8,000lb stone slabs exactly 10ft above the average medium creature and not making them be part of the building itself but actually the reason they are up is hidden immovable rods (paint over the rods with grey paint or something). That way if they activate AMF they will get a couple thousand pounds of rocks falling on them.

That's genius! Dispel Magic by those who know where the rods are also works very well

[Jack_Simth]

Is it realistically possible to challenge high-level adventurers with dungeons? Likely.

However, the conventional hidden doors and magical traps simply will not do. What good is an adamantine gate when the Fighter can smash it in a single round? What purpose serves the deadly pit when the Druid can summon a creature for safe passage without even missing the spell slot?

So - without resorting to Antimagic Fields - what are some things we can do to challenge players past ECL 11?

Traps and simple obstacles in isolation are almost always boring anyway. Even at level 2, that floor that casts Inflict Light Wounds on anyone touching it for each square of movement is pretty harmless (DC 26 Search & Disable Device is take-ten for a skilled rogue). However, if you mix it in with a few ghoul archers? Any time a ghoul is hurt, it just backs off a bit; as long as any given ghoul doesn't get one-rounded, it's healed up very quickly. This can lead to "protect the rogue while he deals with the floor", which can make things interesting. Especially as anyone following the beasts are in for a world of hurt.

That goes all the way up. Golems have spells that heal them, too. Consider a few Clay Golems in a room that has a trap that drops a five-round Energy Substitution (Acid) Delayed Blast Fireball every round. They'll have a lot of temp HP when you first encounter them, and the wall spells a lot of casters use to divide & conquer aren't going to last very long.

You can, of course, also make teleportation required to navigate the dungeon. If all rooms are leaded, you can't scry out of the current room. So you need to figure out where you need to go next, and Dimension Door to it. You'll have some problems if you can't interview the locals.... and of course, each one only knows the rooms that they're supposed to go to occasionally...

There's other things... lots of ways to discourage antimagic. Build the main support columns in the area out of stone from Transmute Mud to Rock. Then have the columns support heavy things. Of course, there's a big, obvious, Symbol spell in each room.

Suppose you make a room that's full of dirt. You must have burrowing or earth glide to be there. Fine for the elemental minions....

Not everyone packs their own air. In a teleportation-required dungeon, fully fouling the air isn't all that hard (get a bunch of dry hay, and cast Fireball). Any team without a bottle of air or something is going to have to hold their breath....

[Tvtyrant]

Nice concept. I'd be worried about paying the 200gp cost for literally every square in a dungeon though...
.

It isn't. It is just the one teleporter proof room that requires that much investment, the rest of the dungeon is made of some cheaper combined traps.

For instance: room where the floor is made of Wall of Illusion overlaying a floor that is full of shaftss. These all fall into a lower room that is full of Oozes, Otuyughs, or other carrion eaters. The room has a Glyph of Downdraft on the ceiling, so flying shoves them into the pit and they have to climb out.

This room follows the invisibility room, so they have True Seeing turned off.

[Beldar]

I had a lot of fun with:
Energy Transformation Field (40' radius. permanent. absorbs magic & uses it to cast a certain specific spell, as if cast by you).

So give them that pit trap or other simple-looking obstacle, but the Transformation field sucks the energy out of whatever spell they try to cast to defeat the simple obstacle & uses it against them (simple attack spells, things like acid fog, summonings etc).

[Karl Aegis]

Few things:

Have many enemies:
High level characters have so many ways to bypass encounters they can fight only what they want to. If they want to burn a few spell slots on fireballs and cone of colds, they should have the opportunity to. The point is to burn spell slots. You don't have to stat most of the enemies, they just die in a single hit. The point is to use spell slots.

Have multiple ways of entry:
Your party has ways around prismatic walls and such. You don't have to make them go to a different part of the dungeon, but they should have the option of spending slots on passwall to get through. The point is to use spell slots.

Traps shouldn't be complicated:
Cheap traps work. You're just checking if your party is playing honest with their buff routines. Random damaging traps that hit an ability score or cause energy drain work just as well as random puzzle rooms with no obvious solution. You're trying to make your party use spell slots on Greater Floating Disk, Passwall, Etherealness or simpler things like Remove Paralysis, Remove Fear, Remove Disease, Restoration or Neutralize Poison. If you're making them get immunities, you're doing it right.

[Kelb_Panthera]

Everyone else is giving you solid security advice so let me point to sources; stronghold builders guidebook, dungeonscape, and draconomicon all have rules for preternatural and supernatural dungeon features. There's also natural hazards that can be sprinkled about in the rest of the environment series, the DMG (obviously), and underdark.

Use as much as you want as creatively as you can in conjunction with the advice given above.

[Anthrowhale]

Halaster's Teleport Cage is good for making teleport exciting in large volumes of space.

[Goaty14]

In lower levels, a mere dungeon consisted of an uninhabited X (because something happened to the original people), now inhabited by kobolds, which the adventurers must kill to get ~100 GP. Higher level dungeons (IMO) should be inhabited places by higher level NPCs. Basically to counter the PCs you send out similarly leveled NPCs. I.e the next 'dungeon' they enter is an inhabited castle, with fully functioning guards and etc.

[Blue Wizard]

Beefing up small monsters is always fun. Throw the right buff routines on even a party of orcs and you can challenge even very powerful characters! I have a friend who nearly got a TPK on a party of 8 level 16 adventurers with 100 1st level warrior orcs.

I myself, in my own campaign have discovered that I can tap into the various resources for kobolds, granting them total immunity to any 3 different energy types I choose! Not even using spells, just running the right breeding program!

Of course, just about every PC caster gets disgruntled when they are fighting a mob of 'useless nothings' and the humanoids' shaman keep countering his spells.

There is a feat, in the Encyclopedia Arcane: Abjuration, that lets you get automatic success on a counterspell when using Dispel Magic. And the 5th or 6th level goblin/orc/kobold shaman has nothing better to do than sit in the back with a readied action to counterspell the party wizard.

[rel]

Running a high level dungeon crawl and then turning off all the PC's high level tricks; teleport, divination, ethereal jaunt is boring. Don't do it. Instead design a dungeon that allows you to use your tricks but doesn't make them auto wins.

Seperate parts of the dungeon and link them with teleport portals, walking through walls / tunneling helps but doesn't negate everything.

Put all or part of the dungeon in a demiplane. Teleporting probably still works but going all the way back to town is tricky enough that the party is incentivised to rest less often.

Go with old school sprawling design but instead of empty rooms put in lower level encounters. They make the players FEEL high level and still sap resources, consuming time if nothing else.

Solving (or breaking) a puzzle is fun at any level feature lots of them.

Be sparing in your rule breaking. Being told 'this sub level has fiat magic that limits teleports to line of sight' is annoying but still fun. finding out the entire dungeon is wrapped in antimagic is not.

Remember that as the GM you can kill the players at any time by saying 'rocks fall'. That isn't your job. Build your encounters appropriately.

The PC's have a lot of tricks now that they are high level. Take advantage of that and include challanges that require said tricks to bypass. Now that the PC's have teleport and passwall not every room needs a door. With divination, not every password needs to be written down.

[Uncle Pine]

Never heard of sickstone. Where can I find more info on it?
It's in Underdark, well hidden in the section about geological stuff.


Something that you will have to do is have a counter for AMF as it would disable most alarms and or traps. My choice for the trap would be making the roof of hallways be layered by 8,000lb stone slabs exactly 10ft above the average medium creature and not making them be part of the building itself but actually the reason they are up is hidden immovable rods (paint over the rods with grey paint or something). That way if they activate AMF they will get a couple thousand pounds of rocks falling on them.
As an adventurer, that sounds awesome! Immovable rods are 5,000 gp a pop, which means that after dislodging the adamantine doors at the entrance I can retire just by raiding this room. Screw the BBEG, I have money now.

[martixy]

I see high level dungeons as places that start messing with the basic assumptions of what a dungeon is. Or even with the basic mechanics of the space, distance, time, matter and energy.

You can have planar slices in different rooms, with all accompanying planar effects, you can have unconnected rooms, you can have dungeons that span multiple planes. Make all the tricks the PCs now possess part of the solution, not part of the problem.

Like right now I'm designing a high-level dungeon that's literally a 4-dimensional maze. By which I mean 4 spatial dimensions - requiring, fly, teleport, plane shift and planar bubble to navigate successfully.

Then there's the matter of the dungeon's ecology. You can, even with low-level mooks seriously challenge a high-level party provided you use the right tactics. Every supposedly game-breaking solution as a weakness that can be exploited by intelligent opponents.

[Kelb_Panthera]

Running a high level dungeon crawl and then turning off all the PC's high level tricks; teleport, divination, ethereal jaunt is boring. Don't do it. Instead design a dungeon that allows you to use your tricks but doesn't make them auto wins.

This is largely correct but there's nothing wrong with shutting down some of the high-level stuff some of the time and even cutting it all off once in a great while. Gotta keep the players on their toes so they don't rely on one trick overmuch.

[heavyfuel]

It isn't. It is just the one teleporter proof room that requires that much investment, the rest of the dungeon is made of some cheaper combined traps.

For instance: room where the floor is made of Wall of Illusion overlaying a floor that is full of shaftss. These all fall into a lower room that is full of Oozes, Otuyughs, or other carrion eaters. The room has a Glyph of Downdraft on the ceiling, so flying shoves them into the pit and they have to climb out.

This room follows the invisibility room, so they have True Seeing turned off.

Ok, but is impeding people from teleporting outside the room, further into the dungeon? A Dimension Lock effect would do, but it's a very expensive spell, spell slot wise.


I had a lot of fun with:
Energy Transformation Field (40' radius. permanent. absorbs magic & uses it to cast a certain specific spell, as if cast by you).

So give them that pit trap or other simple-looking obstacle, but the Transformation field sucks the energy out of whatever spell they try to cast to defeat the simple obstacle & uses it against them (simple attack spells, things like acid fog, summonings etc).

That's a very nice spell. Will definitely use it at some point


Few things:

Have many enemies:
High level characters have so many ways to bypass encounters they can fight only what they want to. If they want to burn a few spell slots on fireballs and cone of colds, they should have the opportunity to. The point is to burn spell slots. You don't have to stat most of the enemies, they just die in a single hit. The point is to use spell slots.

Have multiple ways of entry:
Your party has ways around prismatic walls and such. You don't have to make them go to a different part of the dungeon, but they should have the option of spending slots on passwall to get through. The point is to use spell slots.

Traps shouldn't be complicated:
Cheap traps work. You're just checking if your party is playing honest with their buff routines. Random damaging traps that hit an ability score or cause energy drain work just as well as random puzzle rooms with no obvious solution. You're trying to make your party use spell slots on Greater Floating Disk, Passwall, Etherealness or simpler things like Remove Paralysis, Remove Fear, Remove Disease, Restoration or Neutralize Poison. If you're making them get immunities, you're doing it right.

Many 1HP enemies is one of the things I most dislike about 4e. I don't think I'll do it. I might have enemies that are straight from the MMs and not fiddle with them at all.

Solid advice the rest of it.


Everyone else is giving you solid security advice so let me point to sources; stronghold builders guidebook, dungeonscape, and draconomicon all have rules for preternatural and supernatural dungeon features. There's also natural hazards that can be sprinkled about in the rest of the environment series, the DMG (obviously), and underdark.

Use as much as you want as creatively as you can in conjunction with the advice given above.

I had checked Dungeonscape, but will definitely check out the others.


Halaster's Teleport Cage is good for making teleport exciting in large volumes of space.

That's a very nice spell, even if it's super high level.


In lower levels, a mere dungeon consisted of an uninhabited X (because something happened to the original people), now inhabited by kobolds, which the adventurers must kill to get ~100 GP. Higher level dungeons (IMO) should be inhabited places by higher level NPCs. Basically to counter the PCs you send out similarly leveled NPCs. I.e the next 'dungeon' they enter is an inhabited castle, with fully functioning guards and etc.

Yeah, that makes sense.


Beefing up small monsters is always fun. Throw the right buff routines on even a party of orcs and you can challenge even very powerful characters! I have a friend who nearly got a TPK on a party of 8 level 16 adventurers with 100 1st level warrior orcs.

I myself, in my own campaign have discovered that I can tap into the various resources for kobolds, granting them total immunity to any 3 different energy types I choose! Not even using spells, just running the right breeding program!

Of course, just about every PC caster gets disgruntled when they are fighting a mob of 'useless nothings' and the humanoids' shaman keep countering his spells.

There is a feat, in the Encyclopedia Arcane: Abjuration, that lets you get automatic success on a counterspell when using Dispel Magic. And the 5th or 6th level goblin/orc/kobold shaman has nothing better to do than sit in the back with a readied action to counterspell the party wizard.

I'll probably make a different thread on how can low level creatures challenge a high level party. Thanks!

Encyclopedia Arcane seems to be a 3rd party feat, so I'm not using it.


As an adventurer, that sounds awesome! Immovable rods are 5,000 gp a pop, which means that after dislodging the adamantine doors at the entrance I can retire just by raiding this room. Screw the BBEG, I have money now.

I was thinking the same thing. It might work for one room, or we must find a way to fully hide the Rods.


Running a high level dungeon crawl and then turning off all the PC's high level tricks; teleport, divination, ethereal jaunt is boring. Don't do it. Instead design a dungeon that allows you to use your tricks but doesn't make them auto wins.

Seperate parts of the dungeon and link them with teleport portals, walking through walls / tunneling helps but doesn't negate everything.

Put all or part of the dungeon in a demiplane. Teleporting probably still works but going all the way back to town is tricky enough that the party is incentivised to rest less often.

Go with old school sprawling design but instead of empty rooms put in lower level encounters. They make the players FEEL high level and still sap resources, consuming time if nothing else.

Solving (or breaking) a puzzle is fun at any level feature lots of them.

Be sparing in your rule breaking. Being told 'this sub level has fiat magic that limits teleports to line of sight' is annoying but still fun. finding out the entire dungeon is wrapped in antimagic is not.

Remember that as the GM you can kill the players at any time by saying 'rocks fall'. That isn't your job. Build your encounters appropriately.

The PC's have a lot of tricks now that they are high level. Take advantage of that and include challanges that require said tricks to bypass. Now that the PC's have teleport and passwall not every room needs a door. With divination, not every password needs to be written down.

I see high level dungeons as places that start messing with the basic assumptions of what a dungeon is. Or even with the basic mechanics of the space, distance, time, matter and energy.

You can have planar slices in different rooms, with all accompanying planar effects, you can have unconnected rooms, you can have dungeons that span multiple planes. Make all the tricks the PCs now possess part of the solution, not part of the problem.

Like right now I'm designing a high-level dungeon that's literally a 4-dimensional maze. By which I mean 4 spatial dimensions - requiring, fly, teleport, plane shift and planar bubble to navigate successfully.

Then there's the matter of the dungeon's ecology. You can, even with low-level mooks seriously challenge a high-level party provided you use the right tactics. Every supposedly game-breaking solution as a weakness that can be exploited by intelligent opponents.

All around great advice. Thanks!

[Cosi]

Negating teleport isn't the only solution. It's important to remember that while it's very good at what it does (getting you to your destination), that's not a universally applicable goal. If the dungeon is just a series of hurdles you have to cross to get to the finish line, teleport is really effective. If the dungeon is instead a bug hunt or an exploration mission, teleport loses a lot of its luster. Similar things can be done for most of the high level spells people claim "break adventures", and it is (IMHO) a much better solution than simply putting anti-teleport counters around everything important. It's much more satisfying as a player to realize that using your hammer won't solve the problem than to be told you can't use it at all. The former encourages critical thinking, whereas the latter is just frustrating.

[Beldar]

High level games are great because you as a dm really get to exercise your creativity. They are a lot of work for the same reason. But they are lame if you don't put in that work.

Do some of the same old stuff with new twists. This can often be interesting.
Like using a Mimic: they enter a room & see a chest festooned in locks - obviously something is being guarded - while their attention is on that, the innocent-looking table, or bookshelf, or chair next to it, which is really a mimic with ranks of sleight of hand, is steathily pickpocketing them. It won't attack until attacked - it just pickpockets when it thinks it can & then pretends to be a simple table otherwise.
Of course they'll get their stuff back when they figure it out & defeat it, but it is different & adds spice. ie, it is a defeatable challenge but is new/interesting.

And leave the party guessing from time to time. For instance, once when DM'ing a 17th level (IIRC) party was exploring the 'dungeon' that was the lair of a tribe of beholders (much fun was had fighting the beholders' charmed and buffed minions while the beholders themselves mostly hung back - not present in fights at all but by sending in minions they'd buffed via other, spellcaster, minions, etc).
They couldn't just teleport to the end because the'd never seen it and they didn't know where the thing they were looking for was anyway.
Anyway, I started to say that when the party made it to the Beholder's kitchen, they discovered a bunch of azers & the beholders' lunch (a big pig, a big cow, and a big chicken). They spent their efforts taking out the azers (who released the Dire Boar, the Aurochs (based on an elephant) and a Cockatrice leveled up to be a CR17.
The cockatrice (aka big chicken) was the real challenge there, but didn't look it. The azers were simple azers - just the unchanged cr 2 monsters, but they absorbed a good bit of attention for a round or two before the players sorted things out (and then they focused on the aurochs). They focused on the 'chicken' last.
Cockatrice(s) are normally only 5 hd CR3, but can be buffed to 15 HD and CR 6 (ish) per table 4-4 in chapter 4 of the monster manual. I *strongly* recommend reading that chapter. It takes a little getting used to - knowing what to add to monsters as you level them up and how they progress (mostly by table 4-1 but also by tables 4-2 and 4-3 if they gain size). But with a little practice it goes quickly and it is VERY potent. Taking the cockatrice past CR 6 is not explicitly allowed, but you're the DM - do what seems to be an appropriate challenge - that's your job.
And it is easily explainable as "magical experimentation with creature growth" which is a kind of explanation you see in modules etc all the time - even in the monster manual for certain monsters. And a tribe of beholders with charmed spellcasters could be capable of odd magical breeding proigrams.

The beholders also sent in low-level minions to join other fights from time to time, both to keep the party guessing about the real threat, and later (once they'd learned to disregard those low-level minions), with potions of True Strike and orders to stab the caster every time he attempted a spell. This was enough to disrupt concentration & thus add a tactical challenge to the encounter. It wasn't any kind of trump-card - it could be defeated, but it had to be taken into account & so added spice & got the characters thinking.

Also, somebody asked about redirecting teleports. I looked that up for you (And have had fun using it). It is (from my notes):
Teleport Redirect (Complete Book of Eldritch Might. 1 hr/lvl. 20' diameter sphere. any teleport-subtype spell to or from the area gets redirected to an alternate location you chose at casting time.)

I know you indicated you didn't like to use 3rd party sources. But the reason folks typically reject those is from the potential for abuse and because they can complicate things. But ask yourself if you, as the dm, are going to abuse them? Absurd. You'll use them the same way as you use any other material - to generate challenges that are about appropriate to the party's abilities. And third party books are vetted (unlike homebrew) which therefore has some amount of balance (judge by the publisher - they tend to be consistent).
And high-level games are already complicated.

And you don't have to just frustrate them with Teleport Redirect (like using it to redirect teleports to the inside of a volcano for instance, though that can be fun at times to keep them on their toes and 'burn' some healing spell slots etc, thus making other challenges more challenging).
You can be subtle & get them guessing - like have each room in your dungeon redirect to some other room in your dungeon (ie, they 'make progress', but unpredictably).
Even better if all rooms (or a large set of them) look IDENTICAL. That way they're not sure they even teleported, and things they "already checked for traps" could suddenly "somehow" be trapped (since it is in fact a new room).

[Beldar]

Another thought - there was some discussion about holding up a ceiling with immovable rods so that anti-magic fields become hazardous.
I agree with the idea - this can be an interesting challenge, though I also agree with the observation that immovable rods are expensive and become loot.

So instead do it with Blackstone (from a book on Beholders). This is completely normal, regular stone *except* when it is hit by antimagic - then it disappears (as if it's an illusion) until the antimagic goes away.
Beholders love this, since it can make impassable tunnels that are very very passable to them.

But it could also hold up your ceiling trap.

Another favorite surprise for antimagic is to shrink-item something that will cause problems when it suddenly is no longer shrunk & in cloth-like form.
For example, a large volume of acid. But why stop there? It could be at freezing temperatures & in an amount that exactly fills the entire room.
Then it's a race - will hypothermia kill them (Frostburn book describes this), or drowning, or acid-damage?
And good luck casting an escape spell while taking continuous damage that way. The party pretty much has to depend on what magic items they are carrying, which may or may not make it doable (make the walls thin or thick as needed for appropriate challenge).

[Goaty14]

I should've added that higher-level dungeons should (since they have "official" inhabitants) have consequences outside of the dungeon itself, given you just looted their treasury or whatnot


Encyclopedia Arcane seems to be a 3rd party feat, so I'm not using it.

Still, a Kobold Sorcerer with improved counterspell, heighten spell, and +1 sorc casting can auto-counter any spell he sees, up to a maximum of his highest level spell -1. There's also a feat is Heroes of Battle that allows counterspelling as an immediate action, so such an NPC can do other things.


(from a book on Beholders)

Lords of Madness, IIRC

[Beldar]

I agree, doing counterspelling such as that can be very potent & give rise to situations where the players have to stop and think because 'the usual' isn't working.

You wouldn't want to do it all the time, but from time to time it adds to the challenge.

And that reminds me of a good principle for high-level play: defeat the obvious.

In most situations there is one (or a small list) of obvious things the players will try. Counter that & get them thinking. Don't counter everything - only the first thing that comes to mind.

So, if they come across a pit trap & think they'll just fly over it, do things like this:
As they fly over it a formerly-concealed side passage comes into view. This is unimportant, but distracts them briefly. That distraction, combined with the likelihood that the rogue is not stopping in flight to check for traps, probably lets you get a spell-trap off.

Load it with something like Eye of the Hurricane (3.5 spell compendium) for some damage and knockback (likely into the pit they were trying to avoid).
or
Earthbind (also 3.5 spell compendium) if you're on a budget, since it just makes them fall.

Another common "defeat the obvious" bit is, for example, if they love using fire spells, give them a section of fire-immune creatures just to make them think.
If they're big on hand-to-hand combat, put in some creatures that stay at range & shoot the pc's from there. It will make them think.

It'd suck to do that all the time, but some of it freshens things up a bit.

And you can get near-infinite variety of challenges by giving the evil bad-guys a caster or two to buff them, scry on the PC"s and generally use all kinds of PC tricks against the party.

[martixy]

Lords of Madness, IIRC
That's a book featuring beholders, but not the book we're looking for.


~Snikt~

Precisely what I was talking about.

Ever since I started DMing I've gotten real familiar with the monster advancement rules, to the point I can cite size increase statistics from memory.

There are also some other, somewhat meta considerations on the nature of the game:
As a DM you have access to two additional aspects of the game, the players rarely get to mess with:
Quantity and Scale


Quantity: As a DM you are able to deploy significantly more creatures or things to an encounter, than players are usually able to muster. Given the probabilistic nature of the game quantity IS quality. A group of mooks that hit 10% of the time can serve the same purpose as a big bad that hits >50%. Same with saves. You can have mooks that need a 20 to save, but if you got enough of em, well, some will save. This is also THE WAY to deal with save-or-die's, creating an ablative process out of a binary mechanic.
Scale: Keep in mind that many of the effects that PCs are able to deploy are limited in scale, be it spatially, or temporally, or materially in some fashion. This can be exploited both ways. Either you can deploy similar effects, but on a much grander scale - even a low-level effect, working on a large scale can challenge a high-level party. Or you can use scale to mitigate the supposedly game breaking effects a high-level party might wield by not allowing them to solve all of a certain problem, but merely part of it. And that way, which part they solve becomes a challenge of itself.