Quote from: oggsmash on May 31, 2022, 05:01:12 PM
Yeah I prefer a mega dungeon not try to make too much sense.  We can all assume some mad archmage/liche dug it out and started populating it hundreds of years ago and evil critters are drawn to it.  Maybe he was a former adventurer and knew the fastest way to get treasure and magic items is from dead adventurers?  Sort of Like Al Swearengen's line about pocketing all the gold in the gold rush but not being willing to swing a pick once.   I can even say it was in a sort of stasis till the characters entered.  But I rather not try to make too much sense of my magically powered murder hobos going down into underground constructions to kill monsters guarding loot. 

   Just let the fireworks roll.

I don't want to say too much yet, but the first sentence is within the ballpark of why the dungeon exists.

Quote from: oggsmash on May 31, 2022, 05:39:30 PM

  Well...there are people who keep valuables in a safe in a secret portion of their houses (with alarms that protect said safe) and have armed guards and attack dogs on their estates.  You could argue they also have bunkers and extravagant basements (if they have the sort of money to have full security details) and their houses are like mazes.....  If I add underground Nazi Bunkers with treasure rooms from people they murdered....

Speaking of mazes gave me an idea on what to add.  Thanks for the inspiration.

Quote from: Persimmon on May 31, 2022, 07:01:37 PM
And embrace the idea of the dungeon being the center of the campaign.  I think a certain type of player (like me) likes the tent-pole dungeon concept.  In fact, just this morning I was thinking of designing another mega-dungeon for my campaign that would literally be a tent-pole mega-dungeon.  Mysterious circus appears, adventurers get lured into the Big Top and find themselves trapped in a mega-dungeon.  Now they need to find their way out.  Of course the big bad is some kind of evil clown lich, with his minions being directed by an Insane Clown Posse.  Yeah, I know ASE has a bit of this going on, but I'd make it bigger & deadlier.

So take your idea and just go to 11 with it.

The idea I have is to make it so yes, the dungeon could be the center of a campaign, or it could also be used for a short campaign or to get new players experience.

I really like the idea of the mythic underworld where chaos is supreme. Adventurers are lured by the promise of wealth and glory, only to die or be trapped below. A single corpse could help grow and spawn even more chaos, thus having this ever changing ecosystem.

When I put together mega dungeons I embrace the idea of sub levels. So there can be a wide variety between the levels, for example, one that supports ocean adventures on one level with a desert biome one level below. But sub levels support and add buffers between. If you read Metamorphosis Alpha, and what Jim Ward did with the starship Warden, I think that captures a really cool mega dungeon feel.

I do not think mega dungeons HAVE to be illogical, I just think they CAN be. We've all read the stories of the bowling alley for giants. To me, that works.

Interested to hear more about OP's plans.

Quote from: FingerRod on June 01, 2022, 10:48:59 AM
I really like the idea of the mythic underworld where chaos is supreme. Adventurers are lured by the promise of wealth and glory, only to die or be trapped below. A single corpse could help grow and spawn even more chaos, thus having this ever changing ecosystem.

When I put together mega dungeons I embrace the idea of sub levels. So there can be a wide variety between the levels, for example, one that supports ocean adventures on one level with a desert biome one level below. But sub levels support and add buffers between. If you read Metamorphosis Alpha, and what Jim Ward did with the starship Warden, I think that captures a really cool mega dungeon feel.

I do not think mega dungeons HAVE to be illogical, I just think they CAN be. We've all read the stories of the bowling alley for giants. To me, that works.

Interested to hear more about OP's plans.

The basic premises is that the dungeon was used by a cult of Necromancers 300 years ago as a temple as well as living quarters.  It is believed that many treasures such as gold coins as well as expensive religious relics still remain which has attracted many adventures looking for the underground fortune.   The cult, in  an effort to keep their enemies and thieves out have heavily trapped the entrance and other areas of the dungeon.   With further investigation the players will find out that the cult was despised and had many people attempting to take them out.

That is a brief idea of what I am going for.    There is more to it, but that is the gist.

I haven't played many PnP megadungeons, maybe only a couple (13th Age's Eyes of the Stone Thief and one other that I cannot remember right now). However, if CRPGs count, then we could include Arx Fatalis, Ultima Underworld, Daggerfall, Demise: Ascension, etc.

Things I look out for in my megadungeon:

- multiple regions with their own biomes or points of interest
- communities with intriguing denizens
- factions are cool
- great, deadly depths for spelunking, that require players to plan resources carefully

I've designed a couple of megadungeons before, though never published any. I draw inspiration from CRPGs, though I plan to go through some of the TSR modules to further educate myself.

Quote from: mudbanks on June 02, 2022, 04:04:11 AM
I haven't played many PnP megadungeons, maybe only a couple (13th Age's Eyes of the Stone Thief and one other that I cannot remember right now). However, if CRPGs count, then we could include Arx Fatalis, Ultima Underworld, Daggerfall, Demise: Ascension, etc.

Things I look out for in my megadungeon:

- multiple regions with their own biomes or points of interest
- communities with intriguing denizens
- factions are cool
- great, deadly depths for spelunking, that require players to plan resources carefully

I've designed a couple of megadungeons before, though never published any. I draw inspiration from CRPGs, though I plan to go through some of the TSR modules to further educate myself.

Thank you for the input.  I will keep all of this in mind

This might be useful: consider if your dungeon fits in the "underground nightmare" or "gygaxian naturalism", or both.

https://methodsetmadness.blogspot.com/2020/07/lessons-from-darkest-dungeon.html

5 - Underground Nightmares x Gygaxian Naturalism.

Since the beginning of RPGs, dungeons have been built in two different (and somewhat antagonistic) structures.

In the first, the dungeon is a dreamlike and almost inexplicable place, containing dragons bigger than the tunnels would allow and creatures that have no obvious ways to feed themselves - as if they came from a nightmare. In the second structure, the dungeon was created for a reason, and the creatures that live there are part of a (somewhat) coherent ecosystem ("Gygaxian naturalism").

In DD, the dungeons fit into the first model, but the game makes some concessions to the second, with aquatic creatures in the most flooded environments and mushroom-men living in the caverns.

The lesson here is that even in the unexplainable environments of a nightmare, having some thread of rationality is useful in giving players some chance to prepare themselves adequately to face the challenges that lie ahead. If there was no predictability, a huge part of the "preparation of resources" phase would be lost, since there is no way to choose the best tools if there is no clue as to what is to come.

Quote from: GhostNinja on June 01, 2022, 10:25:00 AM

Quote from: weirdguy564 on May 31, 2022, 05:35:49 PM
The main point is a logical reason for why it even exists. 

People I know do NOT keep their valuables at the deepest, farthest end of an underground maze lined with traps, or let monsters live there.

There is a logical reason for this Dungeon to exist.  I can't get into that right now, but this has been pretty much planned out.  I am just looking for additional things to add.to the dungeon.

Needs to be a market and a food truck rally.  This is most important.

My "dungeons" usually were nothing like a traditional cave full of creatures and booby traps. 

Often they take the shape of some mundane structure or just a place.  Like a ruined castle, or some old and abandoned building.  Or a big shipwreck. 

One I've done recently was a canyon that had a vaulted ceiling built over it, converting it into a cathedral to the world's nature god, complete with stream running thru it, an alter at the far end, and a icon of magic power that has turned the wildlife hostile to intelligent life, including the cult that built this place.  They got ate.  Should have thought that thru, but now we have a run down tunnel system that the giant ants have dug up and buried bits of it, creating a maze. 

Stuff like that

While I am not a big fan of mega-dungeons, as a player and a DM.  I can tell you what would encourage me to buy your book.  Hopefully it will be helpful to you.

New monsters.  Create some new and interesting critters for the players to fight/run away from/negotiate with.  This includes NPC's.  Pictures are always a plus.

New items, magical or otherwise.  Give them cool names and a history for the players to discover.  Maybe a drawback that offsets the cool powers that the item bestows, so a character would have to weigh their options when considering using the item.  Once again, pictures are a plus.  Also, make weapons look like actual weapons from history, instead of ridiculous anime-looking weapons with gigantic blades/heads that would break your wrists if you tried to swing said weapon. 

An interesting map. 

A good plot.  I know we OSR types are not supposed to give a shit about "story", but give the PC's good reasons to delve into your mega dungeon other than loot and xp.

Rumor tables. 

Quote from: Svenhelgrim on June 04, 2022, 09:54:01 AM
While I am not a big fan of mega-dungeons, as a player and a DM.  I can tell you what would encourage me to buy your book.  Hopefully it will be helpful to you.

New monsters.  Create some new and interesting critters for the players to fight/run away from/negotiate with.  This includes NPC's.  Pictures are always a plus.

New items, magical or otherwise.  Give them cool names and a history for the players to discover.  Maybe a drawback that offsets the cool powers that the item bestows, so a character would have to weigh their options when considering using the item.  Once again, pictures are a plus.  Also, make weapons look like actual weapons from history, instead of ridiculous anime-looking weapons with gigantic blades/heads that would break your wrists if you tried to swing said weapon. 

An interesting map. 

A good plot.  I know we OSR types are not supposed to give a shit about "story", but give the PC's good reasons to delve into your mega dungeon other than loot and xp.

Rumor tables.

I plan to have some new monsters.  I appreciate your insites and they are noted.

I wrote this around 2007 or so (can't recall for certain). It received quite a bit of attention at the time.

The Dungeon as a Mythic Underworld

There are many interpretations of "the dungeon" in D&D. OD&D, in particular, lends itself to a certain type of dungeon that is often called a "megadungeon" and that I usually refer to as "the underworld." There is a school of thought on dungeons that says they should have been built with a distinct purpose, should "make sense" as far as the inhabitants and their ecology, and shouldn't necessarily be the centerpiece of the game (after all, the Mines of Moria were just a place to get through). None of that need be true for a megadungeon underworld. There might be a reason the dungeon exists, but there might not; it might simply be. It certainly can, and perhaps should, be the centerpiece of the game. As for ecology, a megadungeon should have a certain amount of verisimilitude and internal consistency, but it is an underworld: a place where the normal laws of reality may not apply, and may be bent, warped, or broken. Not merely an underground site or a lair, not sane, the underworld gnaws on the physical world like some chaotic cancer. It is inimical to men; the dungeon, itself, opposes and obstructs the adventurers brave enough to explore it. For example, consider the OD&D approach to doors and to vision in the underworld, as described in Vol. III of the original rules:

"Generally, doors will not open by turning the handle or by a push. Doors must be forced open by strength...Most doors will automatically close, despite the difficulty in opening them. Doors will automatically open for monsters, unless they are held shut against them by characters. Doors can be wedged open by means of spikes, but there is a one-third chance (die 5-6) that the spike will slip and the door will shut...In the underworld some light source or an infravision spell must be used. Torches, lanterns, and magic swords will illuminate the way, but they also allow monsters to "see" the users so that monsters will never be surprised unless coming through a door. Also, torches can be blown out by a strong gust of wind. Monsters are assumed to have permanent infravision as long as they are not serving some character." (The Underworld & Wilderness Adventures, pg 9)

"Special Ability functions are generally as indicated in CHAINMAIL where not contradictory to the information stated hereinafter, and it is generally true that any monster or man can see in total darkness as far as the dungeons are concerned except player characters." (Monsters & Treasure, pg 5)

Notice that all characters, including those which can see in normal darkness (e.g. elves, dwarves), require a light source in the underworld, while all denizens of the place possess infravision or the ability to see in total darkness. Even more telling, a monster that enters the service of a character loses this special vision. Similarly, characters must force their way through doors and have difficulty keeping them open; however, these same doors automatically open for monsters. This is a clear example of how the normal rules do not apply to the underworld, and how the underworld, itself, works against the characters exploring it.

Of course, none of this demands that every dungeon need be a mythic underworld; there could be natural caves and delved dungeon sites that are not in the "underworld" category, and follow more natural laws. Nevertheless, the central dungeon of the campaign benefits from the strange other-worldliness that characterizes a mythic underworld.

A mythic underworld should not be confused with the concept of the "underdark." The underdark concept is that of an underground wilderness composed of miles of caves, tunnels, delved sites, and even whole underground cities. This is a cool fantasy concept, but is distinct from the concept of a mythic underworld that obeys its own laws and is weird, otherworldly, and apart from the natural order of things. (There is no reason a referee couldn't join the two concepts of underworld and underdark, though.)

Some common characteristics and philosophies for a mythic underworld dungeon (keep these in mind when creating your dungeon):

• It's big, and has many levels; in fact, it may be endless
  
• It follows its own ecological and physical rules
  
• It is not static; the inhabitants and even the layout may grow or change over time
  
• It is not linear; there are many possible paths and interconnections
  
• There are many ways to move up and down through the levels
  
• Its purpose is mysterious or shrouded in legend
  
• It's inimical to those exploring it
  
• Deeper or farther levels are more dangerous
  
• It's a (the?) central feature of the campaign
  

Creating a "Mythic Underworld" Dungeon

You're all excited about the idea of running a big dungeon in the "mythic underworld" style. You sit down with some graph paper and pencils. You spend some time drawing a nice map of the first level, and start keying. Hours go by. Your wife asks when you're coming to bed. Suddenly the weight and enormity of the task descends on you, stopping you in your tracks. How can you finish? How can you get the whole thing done? How do you keep things fresh and interesting for the players going through it? How do you even begin to go about designing this thing?

I don't have a one-true-way, guaranteed method to offer, but I do have some advice that might help. Most of this is nothing I've dreamed up on my own, but rather bits of wisdom I've gathered from various sources. Gary Gygax's words in the original D&D rule books are a primary source, as are the examples provided by the Monster & Treasure Assortments. Last, but not least, I gleaned much from online sources, including the ideas of T. Foster (Trent Foster), Evreaux, Melan (Gabor Lux), Wheggi, Stonegiant, grodog, and many others. This is also a very broad look at the subject, not delving down into the details of the task.

One thing to keep in mind is that you don't have to create the whole the right off the bat, before you start playing. In fact, attempting that is probably setting yourself up to fail. You can sketch out a "Skull-mountain"-style elevation or side-view of the dungeon, including some deeper levels, but you needn't draw and key the entire thing. Instead, start off with the first three levels, and start running it. You can certainly have a framework or general idea of what you'll be placing in the deeper areas, but you don't need to finish (or even map) those areas, yet. You'll develop the deeper levels (as well as continuing to develop and modify the upper levels) as the game continues.

This is a very cool, and very "old school" approach. Your dungeon will evolve in a very organic manner. During play, the players are going to ask questions and take actions that make you think and give you ideas that never occurred to you. Actual play is going to shape the direction and design of your dungeon, often in unexpected fashion. You and the players will be in a sort of creativity feedback loop, and your dungeon will be all the better for it.

When creating your first three (or so) levels, there are a few general concepts that you should keep in mind. First, remember to offer the players plenty of choices. Even at the entrance to the place, don't give them one path to follow, give them four or five choices to make, right off the bat. For that matter, there needn't be only a single entrance. Have several ways in, with a few of the entrances going directly to deeper areas. Maybe new entrances open up or are discovered as play continues. Another important way to give players choices is to offer them many opportunities to move up and down through the levels. You want the players to decide when they want to go deeper. This isn't a video game where you play through the level to the end with the boss monster, then find the stairs. If they're a group of 1st level PCs, but they want to try their luck and skill on the 4th level of the dungeon, that's their decision.

Also, remember that stairs needn't go up or down a single level, and that's it. Give the players ways to go down multiple levels. Some paths up or down may skip one or more levels. You may be leery of including a stair, shaft, or elevator that spans multiple levels, fearing that your players will go down into undeveloped areas of the dungeon. That's true; they might. However, it's more likely that they will be fearful of going too deep, and even if they do descend to a level you haven't developed, they'll be very jumpy and very likely to stick close to their line of retreat. You can wing a hall or a room, or even an encounter from the appropriate wandering monster table. Usually a group dipping down below their comfort-zone will retreat after a quick look around and a maybe a scare (even hearing a threatening sound can be enough to send them scurrying back to safer ground). Once you know that the PCs are dipping down into those areas, you'll also have the motivation to work on and develop them. There's no goad like regular play to break dungeon-writers' block.

When drawing your maps, include multiple paths and choices, but also keep in mind that you want your players to be able to embark in meaningful exploration. You want them to be able to use their minds and their skill to make real discoveries. Include some dead ends, and leave some space on the map where you might later add stairs, shafts, and secret areas, as your dungeon continues to develop through play. Other desirable features include things like long, twisty passages, where they can't see the end. These will play on their fear (i.e. the unknown), and offer opportunities for interesting pursuit and evasion. A similar desirable feature are "pinch points" on the map. These are locations where access to a larger area or section is controlled by one or two points. Knowledge of and control of these pinch points can be an important factor if the PCs are being pursed and need a place to mount a defense.

Related to pinch points is the concept of a sublevel. A dungeon sublevel is an area that is isolated from the main level, usually by some sort of secret pinch point. In many old school dungeons, sublevels are a kind of reward in and of themselves. They tend to be smaller than full levels, and are often themed, although neither of these is a rule that cannot be broken. Sublevels often contain fantastic elements and large treasures, but they can also be more dangerous than normal. One of the great things about sublevels is that they can easily be added to an existing dungeon layout. This is a good way to incorporate third-party modules into your dungeon, as well.

A large consideration when drawing your maps is how to lay them out. One common choice is graph paper with 6 squares per inch, but that varies by taste, and by the size of the level. I've also seen dungeon maps (especially cavern maps) drawn on hex-paper (e.g. Isle of the Ape uses this approach). However, there is something to be said for eschewing graph paper, entirely, and drawing your maps on plain white paper. This frees you from the constraints of the grid, and you might be surprised to find that your mapping takes on an entirely fresh character, with levels stretching out or sprawling in a much more organic and natural manner. Varying your approach from level to level is another good technique for keeping things fresh. One level might be very maze and grid-like, with relatively thin walls and not much rock, stone or earth between areas. Another might use large chambers, widely spaced, with curving tunnels through thick areas of stone. Trying different approaches to the act of mapping will naturally result in different styles of map, in many cases.

How big to make your levels is another question that will come up almost immediately. There is no one correct answer, but the considerations I've already listed will have an impact. Another important consideration is the "density" of your dungeon, defined by the distribution of monsters. The traditional approach is to create a dungeon with about a third of encounter areas (e.g. rooms) containing monsters. That may seem to be a very "empty" dungeon. However, that empty space serves multiple purposes. It acts as a buffer between dangerous areas. It presents a measure of uncertainty to the players, and they need to balance their desire to search everything and everywhere with the danger of wandering monsters. It offers the benefit of repeat play, since they are unlikely to be able to explore everything on a level before continuing to the next. It offers room to run, allowing for meaningful evasion and pursuit, where the PCs can use the space and multiple paths along with techniques like hold portal and dropping food or treasure in order to extricate themselves from situations beyond their capabilities. It also offers the referee the ability to naturally re-stock, change, and add features (a secret stair to the newly completed sixth level could be penciled into the dusty and unvisited area of the first level, for example).

The question which naturally follows the distribution of monsters is the distribution of treasure. The traditional guideline is that half of the encounter areas with monsters will have treasure. Additionally, one-sixth of the "empty" encounter areas will have treasure, although such unguarded treasure will, no doubt, be craftily hidden and perhaps long-forgotten or guarded by ancient traps or magic. Treasure guarded by monsters may or may not be hidden or trapped. If it includes magic items, those will often be carried or used by the creatures, of course.

A very important consideration, and one that impacts the size of the levels, is just how much treasure should be placed. In the vast majority of old-school D&D games, treasure is the main goal (i.e. the PCs are seeking fortune and glory), and will provide the bulk of the XP. A typical old school campaign might have 80% of the XP coming from treasure, and the remaining 20% coming from defeating monsters. So the amount of treasure you stock your dungeon with will impact how many experience points the PCs earn. You need to provide enough XP to allow them to progress.

For the first level, especially, keep in mind that it's likely that the PCs will "lose" XP through attrition. That is, PCs will loot treasure (and thus XP) from the dungeon, but then die in a later encounter. They'll also overlook some treasure, simply not finding it. They may acquire XP from unexpected sources or side-adventures outside the dungeon, as well, and they may also acquire XP from dipping down into the lower levels, so judging the "correct" amount of treasure (i.e. XP) to place is more of a loose art than a science.

I suggest taking the average XP required to advance for a party of around 5 PCs and using that as a guideline for the amount of treasure you should place. For example, if a first level party needs around 10,000 XP for everyone to advance to second level, you need at least 8,000 XP worth of treasure (i.e. 80% of the 10,000, with the balance coming from monsters). However, taking attrition and missed treasure into consideration, you probably need to at least double that amount. There are several approaches you can take, given this guideline. You can use the treasure tables from the rule books or from various collections of monster and treasure assortments to assist with the process. The exact distribution will vary, of course. If you have a first level of 100 rooms or encounter areas, you might end up with something like this:

• 20 areas with monsters and treasure
  
• 15 areas with monsters (no treasure)
  
• 15 areas with treasure (no monster)
  
• 50 areas without monsters or treasure
  

That would mean 35 treasures, varying in value from hoard-to-hoard, and with the more valuable caches well-hidden and possibly defended by tougher monsters or more dangerous traps. These would be the major encounter areas that most PCs will be seeking.

With some idea of the required treasure out of the way, attention must turn to the monsters that will be placed on the level. As with treasure, the rule book tables and additional monster and treasure assortments that are organized by level provide an extremely valuable tool for the referee. I don't suggest simply rolling everything randomly, but rather using the tables as a springboard for your creativity. Also, examination of the traditional table will show that not all monsters on the first level of the dungeon are "first level" monsters. (Part of skillful play being the ability to evaluate an encounter and know when to run.) The tables indicate a chance for more powerful and dangerous encounters, as well. The referee should choose a handful of monsters he wants to use, or a theme, and then perhaps use random rolls to "fill in" the gaps. When using random rolls, don't be afraid to discard results that don't work. However, one of the benefits of random rolls is their utility as a spur to your creativity. If you get a result that seems odd, don't immediately reject it; instead, give it some thought to see if you can imagine a way that such-and-such combination or situation would make some sense. You might be surprised to that this results is cool ideas and encounters that you might not have considered, otherwise. Lastly, don't feel bound by the monsters on the tables. The tables provide a useful measure for an "appropriate" encounter difficulty for a given level, but you can certainly swap-out monsters of similar difficulty and number. Another useful technique is "re-skinning" well known monsters, giving them a different appearance while using the same stats as the original.

In addition to the difficulty of the monsters, the referee should consider how forgiving to make their exact placement. For example, on the first level, it's likely that any given fight may serious deplete a party of adventurers. Therefore, encounters on the first level of the dungeon might be fairly widely spaced, with small enclaves of monsters, rather than large lairs of closely-placed and coordinated groups. The larger and more coordinated groups are more properly placed on the lower levels. That's not to say that you can't have a well-coordinated lair on the first level, but if all the encounter areas on the level are well-coordinated and closely placed, it will be extremely difficult for a first level party.

When choosing monsters to populate a level, do not overlook the opportunity to introduce opposed factions, tension, and NPCs that might offer the chance for smart play, dialogue, and "politics" within the dungeon. A common criticism of dungeon-based play is that it lacks the sophistication and opportunities for interesting interaction and role-play that are present in cities and such. This doesn't have to be the case. There's no reason a dungeon, even a mythic underworld that operates according to its own rules, must be a random, nonsensical place of simplistic and one-dimensional play. The dungeon can be filled with just as much intrigue and opportunity for dialogue as the King's court; it's up to the players (and the referee, of course), to take advantages of those opportunities.

When considering the second, and deeper, levels, the referee can follow a similar approach for determining the number of monsters and the total value of the treasure. However, keep in mind that you will have less PC attrition as the characters increase in hit points and power, so you won't need to double the treasure, like you might on the upper levels. The first few levels will probably be fairly large, but deeper levels can often be smaller and less sprawling, although this is not a hard-and-fast rule.

I mentioned wandering monsters, earlier, in passing. In an old-school dungeon, the purpose of wandering monsters is to provide a challenge that helps encourage good play. Wandering monsters present a danger that drains resources (e.g. hit points, spells, magic items) from a party for very little or no reward (i.e. treasure). Since monsters are not worth much XP, compared to treasure, wandering monsters are something to be avoided. Smart players will try to avoid, evade, distract, or otherwise bypass wandering monsters. They don't want to spend their resources on wandering monsters, but rather on areas and encounters that will provide a larger reward. They will try to stay focused and avoid wasting time in the dungeon, since wandering monsters encountered are a function of time.

Wandering monsters are typically rolled from a table, by level. Often, the table will include a chance of a roll on a deeper-level's table, as well. I typically include the following elements in my wandering monster tables:

• Strange or unexplained noises, smells, or events
  
• Encounters with monsters from keyed areas on the level. Killing these monsters reduces the total number of monsters from that area.
  
• Encounters with truly wandering monsters that are not from keyed areas. Killing these monsters does not reduce the total from keyed areas.
  
• A chance for a roll on a harder table.
  

I also like to set up my wandering monster tables with a bell-shaped probability curve, so that I can divide them into results that are common, uncommon, rare, and very rare.

This brief treatment of "mythic underworld" dungeon creation barely scratches the surface. I have not mentioned anything about tricks, barely touched on traps, environmental hazards, puzzles, teleporters, light and darkness, air, water, fungus, factions, red herrings, sublevels, and a myriad of similar topics. However, I'm hopeful that this musing might assist a referee contemplating the task of megadungeon creation, and help him on his way. For more advice and details, I highly recommend checking out the various old-school forums, which hold a great wealth of wisdom and experience on creating and running interesting and fun dungeons.

Thank you.  I have noted your points.  Not all of them will make it in, but its a great guide to help me out.