Welcome to the Megadungeon: Intro, Structure, Pace, Spreadsheets

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Category Megadungeon 800 x 400Welcome to the Megadungeon, we got fun and games…

All right, we’re in a hurry here because we’ve got a lot of ground to cover and I don’t want to waste a whole 5,000 word article on introductions. We’re going to move fast. In fact, we’re going to move so fast, I probably won’t even have time for all the swearing and the funny analogies and stuff. This is big kid stuff now.

The Megadungeon is a new weekly series that exists because my Patreon supporters made it happen. It’s a little different from my usual fare. This isn’t basic skills time and this isn’t rules hack time. This is about building a module. An adventure. But it’s about building a complex adventure. And I’m going to assume a certain level of expertise on your part. You should probably be familiar with the basics of adventure and encounter building in Dungeons & Dragons 5E. If you don’t own it, you can get everything you need from the Dungeons & Dragons Basic Rules available for free online.

What’s the project? Simple: I have always wanted to build one of those giant dungeon adventures like Undermountain and Castle Greyhawk. One of those huge, sprawling complexes that the heroes delve into and retreat from, pushing a little deeper each time, uncovering treasures, dealing with monsters, and overcoming obstacles and puzzles. But, most of those things are giant, sprawling labyrinthine kitchen sinks. They are just a huge mess.

Now, you know I’m a big fan of videogames in general. And I’m a HUGE fan of exploration based video games, the Metroid series being the Ur-example. And those video games, when done right, take that whole giant sprawling mass and make an art of the design. Without really letting on, they carefully control traffic flow to provide a well-paced adventure with a solid difficulty curve. They provide enough optional exploration and chances to go off the beaten path that the player really is free to explore and to choose how to deal with the game. They just never face more than a manageable chunk of the game at any one time.

The very best of those games, like Metroid Prime and Bioshock, also tell a story. They tell the story of the environment, through environmental clues and as a reward for optional exploration. Many of those story details provide context for what occurs in the game. Often, the story details even provide clues for dealing with in-game problems.

And, of course, these games also provide a progression. It’s not JUST exploration. First, there’s a sense of opening up the space. As you explore, the area you CAN explore expands as a direct result of your exploration and as a result of your growing power. Second, there’s a sense of story progression. In Super Metroid, you’re hunting Ridley and the infant Metroid, discovering the Space Pirates have been revived, and ultimately defeating the Mother Brain. In Metroid Prime, you’re countering the Space Pirates as they plunder the ancient Chozo Ruins on Tallon IV and eventually locating the source of their power and confronting the mutant Metroid Prime.

In fact, these two distinct modes of gameplay – linear progression through an adventure and free-form exploration and discovery – would seem to be at odds. Except they aren’t. And that’s the beauty of the design. So often, we get wrapped up in the fight over “sandbox” or “railroad” that we forget that the truth always lies somewhere in between. And that SHOULD be our goal, most of the time. Because those two distinct structures provide different types of satisfaction. A well-paced, well-structured narrative and a sense of freedom and accomplishment.

I decided, about six months ago, that I was going to take D&D 5E and I was going to write THAT adventure. I was going to take everything I loved about the Metroids and Dark Souls and Bioshocks and La Mulanas and even Castlevanias and everything I loved about D&D and build the Megadungeon Adventure. Or Campaign. Adventure Path. Whatever you want to call it. As you’ll see (shortly), any one of those names could be apt.

And I was going to write and playtest and publish the thing. I still am. I’m going to get it out there. But I also decided that building it (from scratch) was the sort of thing I should share. I think there’s a lot to discuss in terms of how adventures are designed and how adventures could be designed better.

And that’s what this series is. It’s my design blog. A weekly look at the development of The Most Awesome Megadungeon Ever! If you follow this series, eventually, you’ll have all the maps (at least hand drawn) and encounters you need to run the thing, if you want to print out the PDFs and assemble it. But, when it’s all over, I’m going to take the product and hopefully assemble it into a useful book and PDF or e-book or whatever and sell the thing.

A Word of Warning

If you’re expecting me to s$&% out a map a week and slap some encounters into it, you’re going to be sad. We might not even start mapping for weeks. This is going to be about careful, thoughtful design. This particular episode, once we get done with the introduction, is going to be loaded with spreadsheets. SPREADSHEETS!

In addition, I’m not going to deviate too much from the rules except in some very specific places for some very specific reasons, which I will always explain. This isn’t a test bed for house rules. I’m not trying to mess with the game. As far as I’m concerned, whether this ends up on a store shelf or not, this is a product for publication. For general consumption. And that means fitting things into the framework of the game. Sometimes, that means sacrificing something I want to do to make it easier to run.

So, for example, in this article (after the introduction), we’re going to be looking at pacing and the experience system. And some of you are going to point out that the challenge system is wonky in places. I know. But its not AS wonky as you think it is. I know that too. And I know it would be easier to just dole out milestone experience. But D&D players – MOST D&D players – expect experience points. I’ve got to do that. I’ve got to build the best game I can within the D&D framework. And I’ve got to pick my deviations with care. And ultimately, I’m going to break the experience system a little. It’s going to become necessary. We’ll start breaking it in this very article.

So, to summarize: this is a long project with a lot of detailed design. This is designed to fit as closely within the defined framework of D&D as possible. Be prepared.

Our Mission if We Choose to Accept It

Okay, let’s state the design goals for the adventure a little more clearly and concisely. These will change as time goes on, but it’s important we hammer them out.

Design a Dungeons & Dragons, 5th Edition adventure based on the exploration of a single, large, underground complex (a dungeon) over many experience levels. Exploration will be guided by the design of the environment and expand as the players and their characters become capable of meeting higher level challenges. Exploration will also be guided by various goals, both explicit and implicit, to ensure the players feel a periodic sense of victory. The environment and the various goals of the adventure will conform to the environment’s backstory which will be gradually discovered by the players during their explorations. That backstory will give context to the encounters and setting of the adventure. The adventure should take the characters from 1st level through at least 11th level. However, it should be possible, through their explorations, for the characters to end the adventure at up to 13th level if they are thorough, thereby making the final encounters easier and rewarding their explorations.

Sounds good, right? You’d play that. Or run it. By the way, GMs? If you think you might ever run this for your players, you might want to ask them not to read it. And I MIGHT be assembling a playtest group online once we get to the actual mapping and stocking stages. Well, again, if you think you want to be one of those victims, maybe you want to hold off on reading this. Your call.

Why Turn it Up to 11?

Now, one of the things that might jump out at you before we start on the real meat of today’s article, is that the minimum ending level is 11th. Why 11th level? Seems odd, right? Why not 10th level? Well, 11th level is a milestone level. If you pay careful attention to the PHB, you might notice that there are some sudden “jumps” in the capabilities of the characters. And the most obvious way to spot them is to look for the damage jumps.

For example, take a look at your cantrips. Flame Strike, Sacred Flame, Ray of Frost. Notice that they jump up in damage at 5th level and then again at 11th level (and 17th level). Fighters get extra attacks at 5th and 11th levels. There’s a bunch of other little hidden things that jump at 11th level, but I’ll leave you to discover them. The point is, 11th level is a milestone level. It represents a sudden spike in the PCs abilities.

So, it’s just cool to hit 11th level. But more importantly, if the adventure is starting to wind toward its conclusion when you hit 11th level, that sort of matches up the structure of the adventure with the advancement, right? Bam, we hit 11th level and now we’re in our final mop up. We know that Mother Brain is behind this or where to find Dracula, we’re gathering the pieces of the key for the lock on the final door, whatever. It’s a sense of “final preparations being made.” “We’re ready for this guys, now it’s time for the final push.” So, from that respect 11th level is a good last level of the adventure.

But notice, also, that I noted that the PCs can “overlevel.” That is, while I want them to confront the big baddie or whatever at level 11, I’m willing to let them be a little beyond that. I plan to use optional experience as a driver of exploration. We’ll talk about that in a future article, but I’m already thinking ahead. See, you have to incentivize things to drive the players to do them. If the players search every corner and uncover every secret, they can be even higher than 11th level. They can be MORE ready. And that would be a BIG problem if I cut off at level 10.

See, the difference between level 10 and level 11 is much bigger than the difference between 11 and 12 or the difference between 9 and 10. That’s because 11 is a milestone level. So, if I plan the cutoff for level 10, and the PCs end up level 11 or 12 through optional experience, those optional levels make a HUGE difference. And I don’t want the optional levels to make a HIGH difference. Just a difference.

For those two reasons, I decided that 11th level is the minimum level I want the PCs to achieve BEFORE they have the final confrontation (whatever it is, and it WILL be a big fight because this is a D&D dungeon adventure and people expect big fights in D&D dungeons and I LIKE writing big fights).
See? I warned you. This isn’t just slapping together a map and throwing some goblins over there and Giant Kraid over here and Andrew Ryan in Dracula’s Clocktower.

Pacing and Structure and the Hidden Hand of Experience

Now we’re getting to the meat of things. We’re on to the real topic of the day. Because, what we want to do is come up with a way to PLAN the entire dungeon as a whole before we start building the individual units. That’s the only way things are going to fit together right. So, let’s think about how this adventure is going to flow.

In the end, a megadungeon has a very simple structure. The heroes go into the dungeon, they explore a bunch, they get tired, they leave. At least, that’s what we want. We want a series of delves and retreats, each with a sense of pushing farther. Or pushing in a different direction.

Fortunately, D&D is a really GOOD system for that kind of structure. D&D is built around the idea of an adventuring day, right? Basically, the heroes wake up fresh, have X number of encounters, and then go to sleep. Everything in the game hangs off that assumption (which is why I find it hilarious when people complain about how D&D doesn’t work well when you don’t do that). So that’s good. We can basically the game’s structure to help us structure the dungeon.

Because, even though we want it to look like a seamless dungeon that you can explore in any direction, we really want a series of interconnected adventuring days. We want to think about the structure on THAT level even though we don’t want that structure to be overly apparent. Basically, we’re stapling a bunch of mini-adventures together and fuzzing up the edges.

Once we start thinking in those terms though, we recognize we have to think about something else too. If we treat our megadungeon as a bunch of tiny days of adventure and if we want a sense of growing accomplishment that comes from overcoming major challenges and hitting milestone goals, we realize that each day should probably have some sort of milestone at the end. The heroes have a big fight. Or discover a special treasure. Or a unique piece of lore. The game will feel really good if each one of those days, those miniature subadventures, follows a pace of its own.

Now, I’m going to refer back to a lot of video games as we write this, but let’s look at Dark Souls and Super Metroid. These two games followed that structure more closely than you might realize. The placement of big treasures, boss fights, mini-bosses, and save points or bonfires all represented the “end of an adventuring day.” As did the sudden shortcuts back to the earlier stages that made travel easier. Each one of those things, in its own way, was a victory. Though save points and bonfires were actually a little “off” because some preceded bosses and minibosses for gameplay reasons, and so weren’t really the end of the day. So, the save points that were connected with bosses were part of the bosses themselves.

How does one measure an adventuring day in D&D? Well, the DMG tells us how. DMG 84 tells us how much XP worth of “battles” the heroes can handle before they need to sleep based on their level. A 1st level character should consider 300 XP worth of moderate encounters a full day. So, if we’re planning an adventuring day, it should be the first boss fight that kicks the PCs over to the 300th experience point that day. See? Simple.

Or is it?

Building an XP Roadmap

So, here’s the deal. We want to build a dungeon that takes the PCs to 11th level minimum. And, for the moment, we want to assume we want them to be EXACTLY the right level at all times. Because, before we can start playing with optional XP, we need a good roadmap without the optional side paths.

What we want to know is how many days of adventure our dungeon should fill. And how many encounters each day should roughly include. Now, be aware, we are being very precise right now. When we start building, some of that precision will fall way. We’re not going to build to a mechanically perfect XP curve. We’re going to let the XP curve shape the plan, but we’re going to be willing to allow some wobble. But that’s the future. Right now, I want to see what the perfect curve says to do. Here come the spreadsheets.

Now, I’m not going to keep citing the same tables over and over again. I’m getting all of my info from three tables. Character Advancement on PHB 15, Adventuring Day XP on DMG 84, and XP Thresholds by Character Level on DMG 82.

I start by constructing a simple table just to organize the data.

Building Spreadsheet 1First, character level and XP for that level (you’re 1st Level when you have 0 XP and you’re 5th Level when you have 6.500 XP). Then, subtracting, we can see how much XP you need to reach the next level. So, at 1st Level, you have 0 XP and need 300 XP to get to the next level. At 5th Level, you have 6,500 XP and need 7,500 XP more to get to the next level. Got it? Finally, I also note how much XP an individual character should gain from a medium difficulty encounter at that level.

Make sure you’re clear on how this works.

At 9th Level, you have 48,000 XP, you need 16,000 XP more to reach the next level, and, in each medium encounter, your individual share of the experience should be 1,100 XP. Got that?

Building Spreadsheet 2By simple division, therefore, we can determine how many encounters of medium difficulty you need to gain a level. If you are 9th Level, it’ll take 15 medium encounters at 1,100 XP each to give you the 16,000 XP you need to gain a level.

But, I want to call your attention to something right here. Because this is actually going to become weirdly problematic. Notice that those 15 encounters actually give you 16,500 XP. I have the table set to round everything UP. Why up? Because 14 encounters wouldn’t be enough. And you can’t have part of an encounter. You need a minimum of 15 encounters to get over the 16,000 XP you need to gain a level.

Building Spreadsheet 3Now, we can add a few more columns. We know how much XP a DAY of adventure should contain. So we fill that in. And if we divide the XP per Day by the XP per Enc, we know how many encounters fill an adventuring day.

For example, at 6th Level, your day of adventure should include about 4,000 XP. That’s what you can handle before a rest. At 6th Level, an encounter gives you 600 XP. Remember, these are all per PC numbers. So, you can handle 6.67 encounters in a day before you need a rest. And again, I round up.

Now, I realize there is a really strong argument for rounding DOWN here. Because that 7th encounter is technically 0.33 too many encounters and could kill the PC. And I agree, but I’m actually going to come back and adjust for this later. Right now, we’re going to round up because we want at least as many encounters as possible to fill a day. We would rather come up over than short. And we’ll fix the increased danger problem later. Cool?

Now, if we divide Enc Needed to level by Enc per Day, we can find out how many days of adventure the PCs should spend at a given level.

For example, a 4th Level PC needs 16 total encounters to gain a level. That PC can handle 7 encounters per day. So, the PC needs three days of adventure to level.

If you’re really, really paying attention, you’ll notice that I just introduced a HUGE rounding problem. And I did. And I know about it. See, technically, that 4th Level PC needs 2 days + 3 extra encounters. Three and a half days. So, there’s three whole extra encounters worth of XP if we assume an entire third adventuring day.

BUT… half a day sucks. See, we’re going on the assumption that we want every day to have just enough adventure in it to be fun. We don’t want short days or single encounters. Those days are boring and they don’t work well within the framework of D&D. So, we’re overestimating EVERYTHING. But remember, we just want to see how things are going to work out.

Building Spreadsheet 4So, let’s see how things work out. By the way, notice I extended my spreadsheet down to 13th level. That’s because I don’t want the PCs more than 2 levels higher at the end. 13th level should be the maximum level. And I’d prefer to end at 12th.

So, we know the Days Needed and the Encounters per Day. If we multiply those out, we get the Total number of Encounters at each level. And you can see that it’s a lot more than the Encounters Needed. That’s because of those rounding errors. That’s okay. Remember, we’re building to a solid pace first and foremost. We want to know the ideal. And then we’ll work out how to fix it.

If we multiply Total Encounters by XP per Encounter, we get the XP Gained for a PC at that level and then we can keep a Cumulative XP total.

So, at 3rd Level, we expect to spend 2 days adventuring and to have 8 encounters each day, for a total of 16 encounters. Each of those encounters is worth 150 XP, so we’ll gain a total of 2,400 XP. Based on our previous total, that brings up to 3,300 XP.

Now let’s see how badly off all those rounding errors make us.

By the BookI added a few columns. First, how much Excess XP is gained over what is needed. At 4th Level, for example, you need to gain 3,800 XP, but you’ll actually gain (based on the encounters and days we calculated) 5,250 XP, which means you have an excess of 1,450 XP. I also keep a running total of the Excess Cumulative XP.

And then, to make things easy to visualize, I added two columns. The first column tests whether your level has gone too high. For example, at the end of your 8th Level adventures, you have 66,300 XP, which actually brings you to 10th Level. Your level has gone up too fast.

I also turned around and check to see if the rounding errors made the adventures too dangerous. That is to say, if I multiply back the actual XP by the actual encounters in the day, is it within 5% of what the DMG defines as a safe adventuring day. The only factor here is rounding up the number of encounters in a day. And we can say that at 10th and 11th level, the day has gotten a little dangerous.

So, that isn’t QUITE going to work. I mean, we do want the option to be overlevel, but we want to it come as close to the end as possible. So, let’s start playing with some numbers. That’s one of the reasons you make a spreadsheet. For example, what if we assume that absolutely every adventuring day is exactly 6 encounters.

Always 6Wow! That actually kind of works, doesn’t it? We can see there’s a trend of overleveling, but it’ll happen after the adventure. And we could stop here and let this define our pace. Just divide our megadungeon into 6 encounter bite sizes chicklets of adventure and be done with it. And it’d probably feel just fine.

But, I can’t leave well enough alone and I’ve got this feeling that being that highly patternized about it is kind of dull. At 3rd and 10th level, the heroes can handle at least two more encounters in a day, so we’re pushing them to retreat early. And I worry that the overall structure will feel too clockwork.

Let’s play with another variation. What if we assume every level involves just 2 days of adventure.

Always 2 DaysWell, the high levels are still creeping into dangerously long days. And worse, the party spends a chunk of time underleveled. Which means they are in more danger. They catch up in the end, but that won’t work.

What if I now go back through and just fiddle. Try to stick to 6 to 7 encounters in a day and 2 to 3 days. That way, there’s some variation. Can I find something that works?

By the Book FixedWell, look at that. It works. Still trending toward too much XP, but that might help us with the optional extra levels. Though I worry that we’re too close. Going into the last two days of adventure, we close to 12th level. At the end of 10th level, we need just 850 XP or one encounter to gain 12th level, which means by the end of the first day of 11th level, we’re guaranteed to be 12th level. We wanted 12th level to be optional, a prize for good work. Not a guarantee. But this still mostly works.

We’re just not going to use it.

The Treadmill and The Ratchet

It’s time to talk about breaking a rule here. Remember how I said we’re going to work as well within the D&D framework as we can, but we’re going to deviate in calculated spots where we can get away with it? Good. Let’s talk about the Treadmill.

In D&D, the challenges you face increase in difficulty as you gain levels. And it SEEMS like that’s a good difficulty curve, right? You’re always just strong enough. But that actually sucks. Because it robs you of an important experience. Once again, I’m going to refer back to Metroid. Specifically Metroid Fusion because it’s most noticeable there.

Throughout Metroid Fusion, you level up your gun. And gun level ups do two things. First, they change the size and shape and general physics of your beam. The beam gets bigger, it can penetrate enemies it doesn’t kill rather than stopping, it can go through walls, whatever. But the general amount of damage the beams do also increases.

Also, as you go through the game, the amount of damage enemies can take before they die increases. And because the gun upgrades come at specific points in the game, you’d think these two things would stay in lockstep. But they don’t. Actually, you start encountering higher difficulty enemies BEFORE you find the next gun power up. And that does something very interesting.

Before you find the gun upgrade, you feel the difficulty ratcheting up. It feels like the game is getting harder. Which is should be. And you can point to the number of shots it takes to kill an enemy as direct proof. Then you find the gun upgrade and suddenly you feel vastly more powerful. Because now, the number of shots it takes to kill an enemy has decreased. Those enemies are much easier now. That upgrade feels like a significant gain in power. Eventually, the enemies start to increase and difficulty again. And you start to feel the difficulty climb. And then you get a better gun and you feel more powerful.

The difficulty and your power are always climbing, but they are wobbling. And that creates both a sense of increasing difficulty AND a sense of increasing power. Sometimes, the game feels like it’s getting harder. Sometimes, you feel like you’ve gotten more powerful. And you really do want both of those feelings.

Could we do that?

I mean, D&D 5E is kind of on the easy side to begin with. The game favors the PCs a bit more than past editions have (except 4E). The PCs can handle more danger than the game tells you to throw at them. I say this from experience. And, in fact, if you look very carefully at the XP Thresholds by Character Level, you’ll notice that, except at very specific points, a Hard encounter for one level is actually worth more XP than a Medium encounter of the level above it. So, at 5th Level, for instance, a hard encounter includes 750 XP per PC. But at 6th Level, a medium encounter only includes 600 XP per PC. A medium 6th level encounter is actually easier than a hard 5th level encounter. There’s only a few really weird spots where that isn’t borne out. 1st and 2nd level notably, but also, oddly 4th level. But something really weird is going on between 4th and 5th level and I can’t figure out what the hell is happening there. If you look closely at the XP math, for example, the game seems to want you to spend a lot more time at 5th level than any other level. That makes sense, though. 5th level is a milestone level.

Imagine this, hypothetically. Let’s say you broke your level progression into chunks of three levels. Say, 6, 7, 8 are one chunk. A tier. And let’s say we want to get that ratcheting feeling. Let’s say we want the game to feel harder at some levels and easier at others.

What if, during the run from 6th to 8th level, your encounters were all built on 7th level difficulties? At 6th level, individual encounters would feel slightly harder. We’re building to a slightly higher XP budget. Now, your adventuring day could handle fewer encounters and each encounter would feel a little bit scarier. At 7th level, you’d find your groove and feel comfortable. And at 8th level, the individual encounters would feel easier. Meaning, you’d also plow through more of them in a day. Overall, because the length of the day can change, you’d probably end each day having burned the same amount of resources. But the individual encounters would feel different.

In fact, apart from creating a more interesting sense of pace, that might help smooth the rough edges around allowing free exploration. If the players do wander off the critical path, well, things are fuzzy enough that they should probably be okay. We only really need to keep a tight control over those tier breaks. It’s okay for a 3rd Level character to wander (briefly) into a 5th Level area, but we want to keep them out of the 6/7/8 zone. Or the 9/10/11 zone.

Except… this doesn’t work at 1st and 2nd level. First of all, those levels are the apprentice levels. Characters don’t have their full slates of abilities yet. Second of all, those levels are delicate. 1st and 2nd level PCs are kind of easy to break. Trust me. I’ve broken a lot of them. Third of all, those levels are designed to go by quickly. Those levels should only require one day of adventure apiece. So, the PCs can’t really adjust their schedule without screwing up the pacing curve.

So, what if we assume 1st level and 2nd level happen normally. And after that, every three levels is a difficulty tier. Let’s go back to our first spreadsheet, before we started overwriting things, and see how the progression works if we assume that the XP per Enc is based on tiers.

TieredInteresting. Notice, we get a pretty good advancement. We don’t really underlevel. We start to overlevel around 10th level. But we do have a bunch of days that push the PCs just a little too hard. Also, the days at 5th Level are awfully long. 14 encounters a piece? That’s too much.

So, we start to fiddle again. And I won’t go through that step by step. Suffice to say that by fiddling with the number of days and the number of encounters at each level, I eventually find a progression that I like. And one that really nails down the idea of being just about exactly 11th level AT the start of 11th level. That is, at the end of 10th level, a PC is only 800 XP over the requirement for 11th level.

Tiered Wiggle

Notice, also, I added one more column. And it’s just a thing to eyeball for the moment. I was just curious. How much extra XP worth of wiggle room did I have at a given level. Basically, it’s just a measure of how short a PC is of being overlevel. So, at the end of 4th Level, you’re 4,850 XP shy of actually hitting 6th level. Honestly, that column isn’t useful for anything other than an eyeball. Because it’s cumulative.

Anyway, let’s assume that progression (the Tiered Advancement and Wiggle Room (Fixed)) is the one I’m going to start with. It certain seems to do everything I want it to. So, now, let’s figure out how much optional XP the adventure can tolerate.

FinalI’m not going to lie. I just screwed around to get this. I really did. I condensed the original spreadsheet down to show the amount of XP gained from planned encounters (Enc Exp Gain) and the cumulative XP gained from planned encounters (Enc Cum Exp). I then added a few more columns.

My assumption (at least to start) was that optional experience would come from optional encounters. There’d be some number of optional, missable encounters in the game. If the PCs find each and every one of those and deal with them, they should be able to hit level 13 by the end. Possibly before the end. To make things easy, I assumed they would just be leveled encounters like everything else, that they would be worth the same XP as a medium encounter of the same level.

Optional Encounters is just the number of optional things I can include at that level. Optional Experience Gained multiplies those by the XP per Encounter. So, at 5th level, in addition to the planned encounters over three adventuring days, there are 3 optional encounters floating around worth 250 XP each for a total of 750 XP potential optional XP at 5th level.

The Total Cumulative Experience column shows the total of both Encounter and Optional experience. That’s the XP total for a single PC assuming they find absolutely everything. And the Total Level column lets me know when they’ve gotten an extra level. So, at the end of 8th Level, a really diligent party might push all the way to 10th level, for example.

And that’s okay. Even with all the optional XP, it doesn’t become possible to overlevel the adventure until near the end. In fact, that’s perfect.

So that spreadsheet, Planned Encounter and Optional Experience Progression, will become our roadmap for planning out the dungeon. That’s the high level structure. It’ll tell us where to expect the cutoffs between adventuring days, where to plan climaxes, where to open up new sections of the dungeon, and so on and so forth. In many ways, that’s the first map of this Megadungeon.

Don’t Freak Out About Encounters

I could end here, but I want to calm some titties here because I sense I might be scaring some of my audience. I keep using the word “encounter,” and obviously, D&D uses the word “encounter” interchangeably with combat. Especially when it comes to experience. Now, a dungeon like this is going to skew toward combat. And traps. Deadly things that try to kill people. We’re writing an action adventure. That’s what D&D is. But that doesn’t mean every encounter has to be a combat. And we’re just coming up with an overall battle plan here. We just need to know what our limits are.

Maybe, in the end, we end up shaving down one encounter out of every day so we can give out that XP as a reward for story goals or milestones. And maybe we don’t end up with optional encounters. Maybe instead we break up that 500 XP at 3rd Level for discoveries of importance. We’re going to do all sorts of things like that. But for right now, it’s convenient to think in terms of encounters and days and XP.

I mean, in a few weeks, we’re going to discover a major problem with this whole system when we start considering how to make the dungeon feel “alive.” But we’ll get to that.

For now, don’t worry that I’m just building a giant complex filled with monsters. There will be other stuff too.
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25 thoughts on “Welcome to the Megadungeon: Intro, Structure, Pace, Spreadsheets

  1. Ooooo I’m excited for this series! One thing you didn’t mention that will really screw with this kind of analysis is the phantom experience gap you mentioned yesterday with the minion monsters. As written, it’ll take more days of adventure per level because the day is based on adjusted experience and not earned experience. This is a smaller problem when you have noncombat encounters which give the full experience for the encounter, and with all that wiggle room at the end you’ll come close to breaking even, but those first two levels might be problematic. Just something designers need to consider, looking forward to your solution.

    • Personally, I just give my players the adjusted experience. If this is meant for publication though, this isn’t really a workable solution.

  2. Not only is your thought process airtight, it’s explained neatly and concisely. This is probably the best-edited article on the site so far. I’m not sure if any one concept on the site has gotten me so inspired as this pack of spreadsheets!

  3. “And I MIGHT be assembling a playtest group online once we get to the actual mapping and stocking stages. Well, again, if you think you want to be one of those victims, maybe you want to hold off on reading this. Your call.”

    This would be so much fun! exactly the type of thing I would love to do.

    If this happened, would this be just for your patreons? (You are out of $5 per article patreon spots.)

  4. Would this be the same principle to follow if your building an adventure path to take the characters from lets say level 1 to level 11 as well?

  5. Love this analysis and the master of the obvious in me says this could be applied to something other than a MegaDungeon specifically. It’s a general framework to build any kind of campaign.

  6. This is the kind of analysis that a DMG-style book SHOULD have under the “how to plan adventures” section. It’s one thing to just dump the “this is how much exp an encounter should have” table in there, and quite another thing entirely to analyze it in depth and explain the WHY behind the numbers.

    And teach how to build an entire adventuring day. And to teach how to plan ahead. All things that a DM needs to know, and all things that the DMG doesn’t teach.

    As always, Angry, your site is the DMG that should have been.

  7. Great article.

    I like the analysis you did, and I agree with your points as presented.

    Quick question: How do all these meticulous plans survive the party saying they want to return to the surface and rest before the entire adventuring day is done? What about wandering encounters, cleared areas of the dungeon repopulating, etc etc?

    • They could be trapped in the dungeon. Or there could be urgency that punishes them for taking extra days or rewards them for pressing forward faster. It could be a matter of honor.

      I think what Angry is doing here is laying out a baseline for progression, a framework that can then be used to approach issues like those you mention with data to know what to adjust and how.

      What Angry is doing here is probably more thorough than what Adventure Path designers do, it’s more on the level of what I’d imagine WoW developers do. It’s a fascinating analysis that’s taught me a lot. Although in all honesty, the last time I used a rule-based encounter/adventure balancing tool was back in the D&D Basic boxed sets (I the Master set was the one with the encounter balance guidance). I am comfortable to adjust on the fly. But I’ve also never tried designing so much in advance, with the level of planning Angry is doing here I can see the framework is very useful.

  8. Initially, the Megadungeon was the Angry Thing I was the *least* excited about.

    Boy, was I wrong! This is exactly the kind of math – spreadsheets and all – that gets me excited. I love the idea of ratcheted level bands, and I’m really excited to see what this careful planning produces. Not only am I interested in seeing/buying/running the final product, but it seems like incredibly useful information to have in designing my own adventures.

  9. This is great. It took me a few sessions to get through, but I can’t wait for the rest!
    It also feels this kind of analysis should have been done by the original designers. The tables are too explicit to be willy nilly. Wasn’t the production in the open? Maybe somebody knows the equivalent logic they used to come up with the original tables?

  10. You are not taking account of the difference between encounter-build XP and actual awarded XP. “Adventuring day XP” uses the encounter-build XP which is subject to the modifiers for number of opponents and number of PCs. Awarded XP is purely by-monster. Therefore actual awarded XP is lower than encounter XP for encounter-budget and adventuring-day-budget.

    Because you are using actual awarded-xp-to-level, what this means is that it will work to get PCs to the right level, but there will be quite a lot more than a day’s worth of adventuring per level. I don’t think this is a problem, I like status quo sandboxing anyway. but it might be if you expect a boss fight at the end of every session.

  11. Re level bands – the game has clear level breaks at 5 and (as you say) 11; 5th level PCs are more than twice as powerful as 4th level PCs. 3rd 7th and 9th seem like smaller break points.

  12. I just want to thank you for the perfect timing on this series. I’m at the planning stage of my first take on a full 30-level campaign for 4e, and this post, even being only the spreadsheets, has helped me a lot about planning the advancement. I know 5e and 4e are different beasts, but the thinking behind the preparation is mostly system-free, you just need to input the numbers on the table.

  13. This is great, and really got me thinking. But I have one request. Any chance you could actually throw those spreadsheets out into a place where we could download them for our own use?

  14. Pingback: The blank stares give me an answer #Roleplaying #DnD @AngryGM | FreeRangeGeek's Adventures

  15. This will probably come up later, but the Metroid comparison puts in mind the mechanics they use to divide up the different areas of the map, using different items and abilities as keys to various obstacles.

    One important difference between D&D and Metroid is that while you can regulate the amount of XP the PCs get, they can choose certain class abilities or whether to multiclass, so anything that could be solved through certain class abilities still needs an alternate solution available. Example: The switch to extend the bridge is at the end of a gauntlet that is impossible to pass without some way of gaining a movement speed of at least 40. This can be done by either a barbarian, monk, someone with the Mobile feat, or the Haste spell– but conceivably your party could have none of those, so you’d still need to have Boots of Speed appear somewhere in the treasure beforehand.

  16. Very well presented. I’m wondering how much work it would be to translate this progression into something a little more Pathfinder-y as I have no interest in giving WotC any more of my money for D&D5. I love the thought you put into it, and have no difficulty admitting that you brought up several points I would have never considered. Thank you!

  17. I’ve been using this as a basis to build my dungeon (not megadungeon) for new players meant to run over 7 in-universe days from levels 1-3.

    The math is kind of different since I want to spend more time on the earlier levels (it takes 2 days to get from level 1 to level 2). I ended up assigning the experience given as working on a per floor basis, rather than per encounter, just because the 6-encounter per day model gave out too much experience to make a 1-3 dungeon last long enough to be worth it. I didn’t want to sacrifice the number of encounters per day, because that’s a major part of the balance of the game. So I cheated.

  18. So I think what I am seeing here is that the Game Master wants to know how many days he needs so that the characters can level once each time they go into the Mega Dungeon. I think the exercise shown here is perfect for the Game Master who really wants to know HOW the game works. It is another sort of exploration (for the GM) entirely.

    In the Old School game, Dungeon Level 1 had creatures of Power Level 1 and Dungeon Level 2 had creatures of Power Level 2. The characters would simply visit the level that suited them. If they went deeper there was more risk and more reward. But yes, characters could and often did die. Even so, this was the ultimate in Power to the Player.

    Newer editions put more emphasis on the DM – requiring him to create balanced encounters that were “fair.” In other words, encounters that probably wouldn’t kill the players. Encounters that were too hard were simply not used. This was nice for players who never wanted to lose their character. But it wasn’t much to brag about if your character achieved a high level. At least not in terms of skill. Rather, a high level character demonstrated commitment to the game and time put in.

    So right, in the older style, players chose how much danger to face. Newer players would estimate this badly, perhaps, but they would learn fast.

    I can see the appeal of designing a mega dungeon in the manner shown above. And the whole level equals power paradigm does not really work if the dungeon is all on the same level. In the old school style, one could probably achieve something similar by drawing the dungeon first and keeping the encounters separate (not tied to any given room). When a room is encountered (or a Wandering Monster) he can refer to his list of pregenerated encounters, selecting an encounter that matches the characters’ average current level. It would be acceptable to occasionally choose an encounter that is one level above or below their current level, too. This would allow characters to face threats that matched their level without the need for detailed analysis of experience, number of encounters, etc.

    Plus a DM would not need to create all encounters for all levels. Nothing more would be needed than, say, the characters’ current level and maybe a level below and one higher as well (re: monster power). On that note, the Mega Dungeon could be generated on the fly at random – live during the game. (This is what is done on the Iron Realm Podcast, incidentally).

    Nonetheless, a very interesting article. And absolutely, it does give the DM an idea re: the number of encounters players will need in order to level. Very interesting indeed.

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