General advice on ever-more-difficult dungeon

[Pinjata]

Hey, guys,

I'm making a dungeon for my group. Sort of campaign-ending dungeon. They played throught Phandelver and will get an adittional quest, which should be difficult as is - clearing an old dwarven fort, which was occupied by goblins. PCs are lvl 4, should be lvl 5, as they clear the fort. Thing is, fort leads into a dwarven mine - basically dungeon map after dungeon map, after dungeon map, each with harder encounters.

Now, my question is - how should I go about this? Each dungeon level will be rather small. I'll be using isometric dungeons, which I love, but are not as big: example 1 (https://cdnb.artstation.com/p/assets/images/images/007/399/337/large/martin-w-king-isometric-map-for-print-2-recovered-0-25x.jpg?1505872891), example 2 (https://hobbyte.net/WebsiteContent/Images/Under%20the%20Tavern.jpg), example 3 (https://i.redd.it/syeew4mryuhy.jpg). I mean, I may have hard time, stuffing 6-8 day's worth of encounters in such a dungeon.

My second question is - how do I incentivise my characters to "dig ever deeper"? I mean ever better loot is okay, but it may take time for them to figure out the pattern.

Is there a way for me to prevent them to just clear a dungeon level, return to exit and sleep? It's not really my plan, it is a smart tactic and eventually, encounters will be just too difficult, but still ... thing I'm thinking of.

These are the questions ... I appreciate the answers. :)

[BloodSnake'sCha]

Collapse the entrance and give them a rumer on a second secret exist in the land down under where women glow and man plunder.

A profeciy(I can't get this word right) about a powerful artifact that can only appear in a dungeon like this in a specific time, if they will not get to the end in a week(insert wanted time here) they will miss it.

You fathers bones were stolen by a necromancer that use the lowest level as a lab, if you won't go fast he will make them into a special Death Knights that can only be crafted from the bones of adventurers fathers.

[noob]

The inhabitants of the dungeon started moving the loot to a bigger better protected dungeon for some reason and so the more you wait before looting the dungeon the less loot there is.

[Pinjata]

Collapse the entrance and give them a rumer on a second secret exist in the land down under where women glow and man plunder.

A profeciy(I can't get this word right) about a powerful artifact that can only appear in a dungeon like this in a specific time, if they will not get to the end in a week(insert wanted time here) they will miss it.

You fathers bones were stolen by a necromancer that use the lowest level as a lab, if you won't go fast he will make them into a special Death Knights that can only be crafted from the bones of adventurers fathers.

Let me tell this first: I REALLY appreciate the answers.

With that said: I NEVER NEVER NEVER EVER use lame plot devices like "ntrance collapsing". It just takes player agency away, it is bad GM-ing in my book. It gets even worse, when players find an intelligent way round your collapsed entrance. it's horrible.

Artifact idea is GREAT. I think, they could not resist this. A mad explorer with his map, urging them on, to find this item, that will bring them IMMENSE POWER. This is great idea.

Last one I can't really use, but ... also not a bad one.

@noob
He eh also not a boad one. Not one I'd use, but really not bad.

[Sparky McDibben]

You can find solid advice on this at the AngryGMs blog on abstract dungeoneering, or from the 3rd party supplement "Tyrants & Hellions." (The chapter on Hex, the Minotaur Lord)
Both decent options for running a megadungeon-style game without giving yourself a stroke.

[BloodSnake'sCha]

Let me tell this first: I REALLY appreciate the answers.

With that said: I NEVER NEVER NEVER EVER use lame plot devices like "ntrance collapsing". It just takes player agency away, it is bad GM-ing in my book. It gets even worse, when players find an intelligent way round your collapsed entrance. it's horrible.

Artifact idea is GREAT. I think, they could not resist this. A mad explorer with his map, urging them on, to find this item, that will bring them IMMENSE POWER. This is great idea.

Last one I can't really use, but ... also not a bad one.

@noob
He eh also not a boad one. Not one I'd use, but really not bad.
I can understand about the first one(to say the truth if my players found a way, I will be happy, I DM for the crazy things my players do) it work better in a sandbox where the dungeon resources can be used somewhere else.

I forgot to write something about the third one, It was an example of something that the characters really care about.
Something that will make them rush for revenge.

They were all examples for concepts:
Survival
Greed
Wrath

[NaughtyTiger]

Let me tell this first: I REALLY appreciate the answers.

With that said: I NEVER NEVER NEVER EVER use lame plot devices like "ntrance collapsing". It just takes player agency away, it is bad GM-ing in my book. It gets even worse, when players find an intelligent way round your collapsed entrance. it's horrible.

i really appreciate your lame answer that smacks of bad-GMing... well, not that appreciative, i guess.

[rel]

First of all, know your players. Dungeon crawling is fun but the nature of said fun varies from person to person.
I break dungeon crawling into:

-stories, finding out how things came to be and profiting from them

-puzzles, pushing statues aligning mirrors and pulling levers

-encounters, interesting fights and traps

-obstacles, doors to break, shafts to climb, chasms to cross

-exploration, mapping finding new paths, discovering secret rooms, delving ever deeper

Weaving all this together you have the loot and resource management. These are really two things, they are optional, and again, some like them and some don't.

Figure out what aspects of dungeon crawling you want to include first then address them with your design.

Answering your specific questions:

I would focus on stories encounters and obstacles since you mention them and they probably work better with isometric dungeons than say exploration

To fit many encounters into a small map you can have each room hold multiple encounters, either gating off parts of rooms with obstacles or having the rooms change as the players do things. Or change over time.
Set things up to require some backtracking and have the rooms change as a natural part of the process.

Getting the players to engage with the dungeon generally just requires stocking it with the elements I described above that your players like.

The first thing to know about keeping people in the dungeon is that it kind of breaks the loot and resource management elements of dungeon crawling.
No point in collecting treasure if you can't spend it, no calculation about when to retreat if you can't retreat.
There are work arounds ofcourse but you need to keep it in mind.
Now then, there are a few ways to keep people in the dungeon;
A stick is typically obstacles blocking the way out, placing the dungeon somewhere inaccessible, a timed raid, Proactive opponents that build up or harrass the party when they rest.
On the carrot side, temporary buffs (lasting a day or two), loot that is awkward to remove and likely to get stolen if abandoned but useful for exploring and temporary weakening of challenges all encourage the party to stay put.

[Sorinth]

Leave a hint about a powerful artifact/riches in a treasure vault to entice them into exploring the dungeon. Then once they take their first long rest have a rival adventuring group show up, they are also after the treasure and aren't willing to share it. They wouldn't initially be hostile, but the deeper they get into the dungeon, the more cutthroat they become.

This adds a race condition so that they won't want to go back outside to rest, and instead will want to push on to get ahead of the other group. It can even make taking short rests a more difficult decision.

That said you'll want a number of encounters that either reset themselves or can be bypassed by quick thinking or spells so that one group can get ahead of the other. You'd also want situations where multiple paths that lead to the same place, a shorter more dangerous path, and a longer but safer path.

Besides just clearing the dungeon, if the rival group gets ahead, they might setup traps or restore broken ones to try and slow the PCs down, these can become deadlier the deeper they explore. Maybe some double dealing like having the PCs catch up with the group who look injured and are taking a short rest to heal up. They are willing to trade a map they found for some extra healing potions. The double cross being that the map is a fake that their rogue cooked up to send the PCs down the wrong path.

[da newt]

Make it easy to get lost or turned around - maze.

Include plenty of traps - kobolds are great for this and some parties just can't resist chasing down some fleeing kobolds only to find themselves ambushed.

If they retreat to rest, attack.

A series of clues, and a mystery to solve - indiana jones style.

Capture one of the party and make it a rescue mission.