D&D 5E The Shadow in the Flame: A Workshop on Designing Dungeons, Monsters, and a Villain

[Quickleaf]

There are a lot of questions new DMs (heck, and experienced DMs like me as well) have about how to approach writing an adventure, designing a dungeon, creating/converting a monster or NPC, and how to make this awesome imagined villain actually be awesome in the game. I want to offer my ideas on all of it, but with a focus on how it all works together in actual practice.

This thread merges a couple others, including First time making a serious dungeon and Creating The Bonfire Help with a BBEG. However, the scope goes far beyond these.

Lastly, I'll add that I love hearing ideas and discussing my designs on ENWorld, so I am happy for whatever engagement this creates. This won't be structured like a normal article series or anything, more just me digging into the guts of my design process and sharing things as I create them.

Table of Contents
Step 1: Honing the Idea & Brainstorming
Step 2: Room Lists, 'Massing', and 'Adjacencies
Step 3: Quests & Character Hooks
Step 4: Verisimilitude & Foundational Questions
Step 5: Making Monsters - Part 1: NPCs
Step 5: Making Monsters - Part 2: Monster Variants
Step 5: Making Monsters - Part 3: New & Converted Monsters
Step 5: Making Monsters - Part 4: Hard-to-Convert Monsters
Step 5: Making Monsters - Part 5: Legendary Monsters / Villains
Step 6: Dungeon Mapping - Part 1: Iterative Design & Rough Maps
Step 6: Dungeon Mapping - Part 2: Hand Drawn Maps
Interlude: YouTube Design Chat, Audio Only
Step 6: Dungeon Mapping - Part 3: Sketches
Step 6: Dungeon Mapping - Part 4: Mapping in Three Dimensions

@Imaculata is sharing a "sister" series called Fire and Water: Designing Themed Dungeons. Check it out!

Master List of Resources

Spoiler: Master List of Resources

Blogs about Dungeons
Deeper in the Game A 7-part article on dungeon design
Critical Hits The Architect DM series
Critical Hits Chatty DM's Re-examining the Dungeon
Grognardia Old School Dungeon Design Guidelines (taken with a grain of salt, and a good sense of humor)
Dungeon Fantastic Megadungeon Design
The Alexandrian: Jacquaying the Dungeon Highly recommended 7-part series about mapping like famous Jennel Jacquays
Sly Flourish: Making Awesome Dungeons follows Rodney Thompson's advice about making dungeons "familiar, functional, and fantastic"

Fantasy Demographics
Autarch's Adventurer Conqueror King Alex has a blog post "The Demographics of Heroism" about assumptions of how rare individuals are leveled from 1st to 14th level.
The Magic Tree Tanz deconstructs how many hypothetical NPCs would have "the hero stuff" and survive long enough to do something with their class levels.
The Fifty Percent Rule MontyWild proposed a 50% rule for determining how many NPCs of a given level appear in a world. Not an unreasonable starting point.
D&D vs. USA Demographics Fallencoder does an interesting comparison of adventurers to US armed forces personnel, coming up with probabilities of encounter an NPC of #th level in the world, and in a number of combats. Possibly flawed assumptions, but interesting nevertheless.

Monster Design & Conversion
AngryGM has a good article covering 5th edition monster creation in detail, starting from the very basics
Official WotC Conversion Guide
Brent Newhall's 1e-3e-5e Converter
Pathfinder to 5e Converter by [MENTION=6670944]Kryx[/MENTION]/Mark Lenser
Equating AD&D 2e XP to 5th edition CR (my thread on ENWorld)

Villain & Legendary Monster Design
Villain Builder: 7 part series by Wolfgang Baur
Sly Flourish: Building Legendary Creatures
Secret Planescape Origin of Legendary Solo Monsters (my ENWorld thread)

Hand Drawn Mapping
Dyson's Dungeons Tutorials
Dyson's dungeon mapping symbol key
DMG Mapping Symbols
Cartographer's Guild: A Forum for Cartography Enthusiasts

Verticality in Dungeons
The Architect DM: Give It Some Height
Dyson's Dodecahedron: Vertical Morphology
strolen.com/viewing/Sanctum_of_Water Strolen's Citadel: Sanctum of Water I recently got an error message that strolen's site is not secure, so I've deactivated the link.

Step 1: Honing the Idea & Brainstorming
Ideas are dime a dozen. What really makes an idea interesting is how it's developed. So the first step is actually doing something with the idea.

What prompted me to post is a dungeon/adventure I'm working on called Krak al-Mazhar: Citadel of the Shadow in the Flame; in brief, it's the secret lair of The Brotherhood of True Flame (think: evil arcane society) built into the ridge of a caldera. It's designed for roughly 15th-16th level PCs.

Let's pause and ask "how did I get that number?"

Well, there are 3 reasons. First, it's for an Al-Qadim game I run and I anticipate the PCs being around that level when they confront the big bad evil guy (BBEG). Second, the adventure will feature a fair number of CR 3 undead (e.g. mummy archivists, Lawful Neutral wight "crypt servants", and an upgraded ghast called a "lesser ghul"); which is relevant to the 14th-level cleric's Destroy Undead (CR 3) feature. Third, 15-16th level spellcasters have access to 8th level spells like antimagic field, dominate monster, glibness, and telepathy; this adventure is designed with those sorts of capabilities in mind.

So without even meaning to, I've stumbled onto a design principle: If you have a level in mind for a dungeon/adventure, write to the capacities of PCs of that level. You may even want to design a bit first, and then go back and figure out what level it's suited for once your mind is clear of the initial stages of design.

My first step was to brainstorm as much as I could about the dungeon/adventure, and to that end I used Mindmeister web-based mind-mapping.

A few things stood out to me after I sat back and looked at my vision...

• This is going to be bigger than any dungeon I've ever made myself before. Not mega-dungeon big, but well, big (easily 30+ areas). I've read blogs, asked other DM friends & folks online, and thought back to features of the few awesome larger dungeons that I'd run (Dragon Mountain, Tomb of Horrors).
• There is a lot of custom/homebrew content I am going to want to write. Both to support the feel I am going for (secretive sinister group of power-hungry mages), and because the options for tougher enemies in core D&D are limited.
• I need to think about how the NPCs inhabit the dungeon and their motives and inner factions, in order to support the players in approaching the dungeon from multiple approaches.
• Figuring out the map of this thing is going to require thinking & mapping in three dimensions.

Step 2: Room Lists, 'Massing', and 'Adjacencies'

My next step has been iterative, but is looking much better now than it was at the beginning. I've done this with notecards before, but in this case I opted to use Photoshop. I wrote down all the rooms I could think of. Then I gave them an approximate size in relation to each other – for example, I knew The Great Garden and the Tower of the Bonfire were going to be big areas with sub-areas within them. And lastly, I tried arranging them in a logical way (e.g. the Dungeons should lead to the Water Distillery, because that's where the Brotherhood drain the dead of their precious water -- remember they live in a hostile desert -- and prisoners had better be good for something).

This is still just a conceptual map, and still work-in-progress, but it starts to give a feel of the dungeon...

Resources: Blogs about Dungeons
Deeper in the Game A 7-part article on dungeon design
Critical Hits The Architect DM series
Critical Hits Chatty DM's Re-examining the Dungeon
9 Dungeon Design Secrets YouTube video from Ben at Questing Beast
Grognardia Old School Dungeon Design Guidelines (taken with a grain of salt, and a good sense of humor)
Dungeon Fantastic Megadungeon Design
The Alexandrian: Jacquaying the Dungeon Superb analysis of Jennell Jacquay's dungeon design to derive usable principles
Sly Flourish: Making Awesome Dungeons follows Rodney Thompson's advice about making dungeons "familiar, functional, and fantastic"

One of my favorites from Dungeon Fantastic is "Vary the theme by area." This refers to a variety of entrances, monsters, verticality, themed areas, and challenge levels (and I'd extend it to challenge types).

 

[Scrivener of Doom]

This is really useful. Thanks for posting.

And I really need to check out mindmeister. That looks like it would be more convenient than my usual brainstorming on a whiteboard!

 

[Quickleaf]

Glad you gained something from it [MENTION=87576]Scrivener of Doom[/MENTION]! Yep, mind-mapping is a neat way to get your ideas down.

Step 3: Quests & Character Hooks

What good is a dungeon/adventure is the players don't have a reason to care about it, a reason to step through that archway? Rather than do this later, I like to bear it in mind right from the start, because I think it's that important. While we as DMs do want to create a logical, well-conceived, believable setting, we don't want to do that at the expense of playability.

First, the Quest. My rule-of-thumb is to come up with more than one possible Quests; for a short adventure or side trek you can usually get away with one, but things become much more interesting when 2 or 3 quests can interact. In this case, I've outlined notes on 3 possible main quests (any, all, or none of which a DM might use); in my campaign I'll likely use all three.

[SECTION]The Quest
How do the PCs become involved with the Brotherhood of True Flame? This adventure works best if you foreshadow confronting the Brotherhood several sessions in advance (see the “Legends & Rumors” table for ideas). You may select one of these quests that best fits your group and campaign.

Black Cloud of Vengeance
From the sky comes a black cloud, destroying everything in its path with hurricane winds, fire rain, and lightning bolts. The Brotherhood of True Flame claims credit for the black cloud, claiming it is The Bonfire’s vengeance. Even the wisest of druids and seers can find no way to stop it from consuming the land, save to venture to the Brotherhood’s mythical citadel and either convince The Bonfire to have mercy or bring his rule to an abrupt end.
Further Questions. Why has The Bonfire gone to such extreme lengths for revenge? What will convince him to lay down his vendetta?

Campaign of Terror
A kingdom or city-state the PCs have allegiance to has come under attack by the Brotherhood of True Flame, blackmailing politicians, raiding the hinterlands, and making demands of its ruler. Unless the leverage the Brotherhood has over the ruler is destroyed (if blackmail information) or rescued (if a hostage), the ruler will be forced to submit to the Brotherhood’s demands.
Further Questions. Why have the Brotherhood targeted this ruler specifically? What are their demands of him or her?

Pogrom of Mages
Mages across the land are being targeted by assassins who demand they adopt the practices of the Brotherhood of True Flame on pain of death. The PCs may be hired by a ruler or archmage wishing to stop this pogrom, lose a NPC ally to the assassins, or themselves be targeted only to launch their own investigation which leads them to Krak al-Mazhar.
Further Questions. Why are the Brotherhood seeking to convert mages to their cause, killing those who refuse? And what will get them to stop?[/SECTION]

Next, Character Hooks. One of my favorite approaches to individual character hooks dates back to 1992 when David "Zeb" Cook wrote ALQ1: Golden Voyages. He outlines a Great Treasure which could be any of 10 possible treasures, depending on whether a given player fit the archetype of a Power Gamer, Warlord, Role-player, Storyteller, or Puzzle-solver. The idea probably dates back further, but in my teens I remember being captured by the idea. Turns out that's a great way to design character hooks; certainly, one could use the 12 classes or backgrounds or races with specific hooks, but what I like about Cook's approach was that it really spoke to the player's motives for playing.

I applied that idea to my adventure/dungeon using the 7 player archetypes described in the 5e DMG. I am writing in the long form, like published module, so I can demonstrate what I mean more clearly. Few of my actual DM notes are so organized.

[SECTION]Character Hooks
You can use one or more of the following character hooks to invest your players in venturing to Krak al-Mazhar. The hooks are divided according to the types of players you have in your game.

Actors
The Fiery Redemption. Either you or one of your ancestors supported the Brotherhood of True Flame in the past, and now you seek to take action to make amends for those past evils in Krak al-Mazhar. This may involve sanctifying a desecrated fire shrine, undoing something that a wicked ancestor did, or even confronting a relative who is a flame mage.
The Rescue. An ally of yours has been taken by the Brotherhood of True Flame to their citadel Krak al-Mazhar. This could be someone kidnapped like the janni Amir Heidar Qan or your beloved taken as a sacrifice. Alternately, it could involve a NPC who is in the process of being inducted into the Brotherhood; only your intervention will free them from the false promises of the Brotherhood.

Explorers
The Hidden Mystics. Though others do not believe, you are convinced that remnants of the original mystics of Krak al-Mazhar survive. These mystics, known as The Fire Most Pure, were believed to commune with a divine flame, the secrets of which have been lost for a millenia. Who knows what wonders could be found in those ruins beneath the scorching sands?
The Portal. You’ve been tasked with finding a portal or gate into Krak al-Mazhar while on the inside. This may be to let a crusading army follow up on your adventure and purge the Brotherhood of True Flame, or it may be to lead a exodus of the Brotherhood’s slaves to safety. Alternately, you may be tasked with destroying a portal to the Plane of Fire by an efreeti noble who does not care for the inroads the Brotherhood makes in the City of Brass.

Instigators
The Death Order. One of your wild endeavors drew the attention of the Brotherhood of True Flame’s holy slayers. Now they will not rest until you are dead, your ashes scattered, and your fields salted. You need to find a way to keep these assassins from continuing to come after you, and braving the heart of their lair in Krak al-Mazhar may be the start.
The Revenge. The Brotherhood of True Flame hurt you or your loved ones in its relentless quest for power, and you’re out to make them pay. All of them. While the caldera that Krak al-Mazhar lies within is believed to be an extinct volcano, tales you’ve heard suggest it may still burn. A fiery doom would be poetic justice for the flame mages, wouldn’t it?

Power Gamers
The Golden Mirror. You’ve learned of a magical mirror of vast power kept within Krak al-Mazhar. The mirror allows one to see anwyhere, teleport anywhere, gaze into the hearts of men, and more. Depriving the Brotherhood of such a mighty weapon would strike a grievous blow to their operations. All the better if the golden mirror ended up gracing the walls of your own stronghold!
The Library. It is said that one does not join the Brotherhood of True Flame without researching a new fire spell. Their arcane library at Krak al-Mazhar must be overflowing with secret spells forbidden to outsider mages. That knowledge will be yours, and if you can avoid whatever heinous price attached to it all the better.

Slayers
The Righteous Kill. The temple of your chosen deity has enlisted your aid to eliminate a specific enemy within Krak al-Mazhar. This could be the erinyes #, the corrupted jann Majnun, or even The Bonfire himself. A more extreme example would be a call to eradicate the entire enclave by any means necessary.
The Tunnels. Deep within the cooled lava formations of Krak al-Mazhar is a network of tunnels overflowing with monsters. Whether you intend to sneak in via these tunnels, smuggle slaves or treasure out through them, or use the monsters against the Brotherhood, you’ll need to hack your way through monstrosities beneath the wastes.

Thinkers
The Mystery. ?
The Spy Games. An informant has given you enough information to find Krak al-Mazhar, but the greater task ahead of you is dismantling a network of flame mages spanning across the land. You’ll need to sow discord among the mages, gather evidence of their conspiracies, break any leverage they have over compelled agents, and find a way to disrupt their operations once and for all.

Storytellers
The Curse. Afflicted with a curse placed upon you by one of the elite flame mages, you’ve learned that simply killing the mage will not end the curse. Instead, you must venture to Krak al-Mazhar and either negotiate with them or devise some other means of breaking the curse. Discuss the nature of the curse with your DM.
The Molten Throne. The Brotherhood of True Flame has fallen to corruption and tyranny, but it could be so much more. You aspire to depose The Bonfire and take his mantle as your own, recreating the Brotherhood in your own image.
[/SECTION]

 

[Quickleaf]

Step 4: Verisimilitude & Foundational Questions

Unless your group is going for a light beer n' pretzels style game or light-hearted dungeon romp parody, you probably don't want the players to have a moment where they ask with incredulity: "Wait a minute, why is there a giant head with a sphere of annihilation in its mouth right here? This dungeon doesn't make any sense."

Not everything needs to make sense, but enough to preserve that illusion which engages the players in the imagined scenario of the adventure/dungeon. It's definitely a balancing act, and one which DMs tailor to the groups they play with (e.g. some players don't really care, and others will relentlessly uncover the slightest scent of phoniness).

I was encouraged over at RPG.net to answer 5 common sense questions to help build the verisimilitude of my dungeon:

1. How do they breathe?
2. Where do they sleep?
3. What do they eat?
4. What do they drink?
5. Where do they enter/exit?

I think this step, for me, also intersects with questions like:

• Who are original occupants vs. current occupants, and what state is the dungeon in?
• Does this dungeon fit as a particular type described in the DMG (e.g. tomb, stronghold)?
• What are the fantasy demographics of the dungeon/adventure setting?

1. How do they breathe?
Most are resistant to fire damage which helps with breathing excessively hot air in places. Otherwise, there's ventilation thanks to a few shafts/lava tubes leading to the caldera's surface. Overlooks and "screen" doors (mashrabiya / jalis) let in airflow as well.

2. Where do they sleep?
They sleep in areas away from the hazardous fumaroles, in quarters (for mages and priests) or barracks (for mamluks and holy slayers).

3. What do they eat?
Precious little game lives in the Great Anvil, the most inhospitable desert in the land, however the Brotherhood do harvest scorpions and beetles, and hunt fire lizards, giant mason wasps, and dangerous salt worms (desert-adapted remorhaz). Because of this limited diet, they rely on trade with mysterious fierce janni tribes who don't mind charging exorbitant prices to the sinister cultists, or else shipments by their allied merchants usually via teleportation circle and sending stones (made of volcanic rock from the caldera). When food is scarce, they force captive janni to create food and water (a spell forbidden to their priests of Kossuth as it involves water).

4. What do they drink?
There is an aquifer deep below the caldera, but it has become tainted with chlorides & sulfides. The alchemists and priests of the Brotherhood have devised a means of extracting the acids/poisons to yield pure water (as well as useful ingredients for more nefarious purposes). Additionally, the Brotherhood stockpiles water in the event that something happens to their water source, though these stockpiles wouldn't last longer than 1 week if rationed, less if not.
Additionally, they extract water from the dead (a la Dune) in a macabre sacred ritual.

5. Where do they enter/exit?
There are six seven ways into Krak al-Mazhar, the first six used by the Brotherhood, and the last one unused.

• Narrow fissures lead through the steep sloping "hills" around the caldera, that invariably lead to guarded bridges; three of these lead into the upper levels.
• The Gate of Mysteries opens into the heart of the caldera, and is guarded by horned devils. This is used by slaves working the sulfur mines, entry and exit for new initiates to the Brotherhood, for military drills, and for the very rare departing/incoming caravan.
• A teleportation circle lies at the edge of the caldera ridge, though only the Brotherhood's upper echelon know its sigil sequence, and there’s a rotating password shared among them which if not spoken triggers a glyph of warding.
• A two-way portal to the Plane of Fire is used for welcoming efreet ambassadors/messengers and sending out initiates / exploration parties.
• The Bonfire owns the golden mirror which he can use to open a temporary gate which he can also return through.
• EDIT: Flying creatures can enter Krak al-Mazhar's upper levels through the shadow wyvern aerie, which is often occupied by several shadow wyverns and/or flame mages coming and going on overflights of the caldera.
• Lava tubes used by salt worms (remorhaz) and sand worms (purple worms) trace their way under the fortress; they are kept at bay by the narrowness of the passages and by magical brass gongs that create a sound the worms dislike.

6. Who are original occupants vs. current occupants, and what state is the dungeon in?
The original builders & occupants were the mystics of The Fire Most Pure, who were a more neutral-aligned group revering a mysterious divine flame and had association with an asuras (think: "fire angel"). However, they were corrupted by an internal faction that became the Brotherhood of True Flame which now controls Krak al-Mazhar.

7. Does this dungeon fit as a particular type described in the DMG (e.g. tomb, stronghold)?
Krak al-Mazhar doesn't neatly fall into any one dungeon type. It's a stronghold, a school for flame mages, a wizard's tower, and a dungeon for captives/brainwashed victims rolled into one. It's also built on a planar gate, it has a political/ambassadorial role, and there are sulfur mines on site. This is probably the upper limit of how complex you want to make your own dungeons, but I hope to show how these various "types" can feed into one another.

8. What are the fantasy demographics of the dungeon/adventure setting?
This is something which ties into world-building. While you can put whatever monsters you dang well please into your dungeons/adventure settings, when you start getting into larger dungeons thinking about the demographics (and their implication) can help you conceive of the range of monsters, how they operate, and reinforce the verisimilitude of your dungeon.

In my case, I'm dealing with a village-sized population at this dungeon, and most of them are NPCs. This means, I want to think about NPC demographics. For example, placing 60 NPCs there who have the spellcasting ability of 12th level wizards has implications for the campaign; namely, that there are enough 12th level wizards in the land for it to be reasonable to say that 60 of them focus on fire magic, and swear allegiance to the Brotherhood of True Flame, and center their operations at Krak al-Mazhar. That's a lot of wizards!

I opted for something a bit more moderate...

[SECTION]Krak al-Mazhar houses roughly 600 members of the Brotherhood of True Flame and their slaves. The occupying NPCs, not including any of the monsters allied with them, can be divided accordingly:

40% (240) slaves (commoners) (0th level) (CR 0)
12% (72) cultists training as fedayeen (1st/2nd level) (CR 1/8)
12% (72) guards training as mamluks (1st/2nd level) (CR 1/8)
18% (108) mamluks of the Imperishable* (3rd level) (CR 2)
3% (18) cult fanatics aiding priesthood (4th level) (CR 2)
6% (36) Flamedeath fedayeen* (7th level) (CR 4)
6% (36) shig’harakhi* (7th level) (CR 6)
0.85% (5) priests of Kossuth* (10th level) (CR 6)
0.5% (3) aghas of the Imperishable* (12th level) (CR 6)
0.5% (3) black flame zealot assassins (12th level) (CR 9)
0.5% (3) disciples of the salamander* (12th level) (CR 5)
0.5% (3) khaz’harakhi* (12th level) (CR 9)
0.15% (1) The Bonfire* (20th level) (CR ?)
[/SECTION]

Another factor in figuring out these numbers is that I want the PCs to be able to encounter a group of flame mages (let's say 7th level shig'harakhi, which is a fancy name for "lesser flame mage") and have an interesting challenge. For example, a group of 5 (2d4) shig'harakhi would make for a roughly Medium difficulty combat for a group of five PCs of 16th level. Thus, I know I want enough of these lesser flame mages around the dungeon for a chance encounter / clearing out one room not to totally decimate the shig'harakhi forces.

My gut was telling me the total number of shig'harakhi should be at least 5-6 times the size of an "average patrol of shig'harakhi" (so 30-35 lesser flame mages). That ended up being about what I went with.

There's also some story implications from my dungeon demographics – there are no low-level wizards (like there are mamluks and cultists). Why? Because The Bonfire considers them beneath him, sending any such supplicants away until they reach about 5th level (i.e. can throw a fireball) before he will take them under his tutelage. And BOOM, now I've got some fun side quests I can incorporate about a disgruntled flame mage who wasn't accepted by The Bonfire and goes to extreme lengths to prove himself. And a hint that The Bonfire might be impressed by PCs demonstrating a mastery of fire magic, which could work toward their favor in an undercover scenario (and could get them into awkward situations).

Lastly, I did a quick reality check. Would ~360 fighting men/women be reasonable to be stationed/housed at a castle? I thought so, but I double checked...

Krak des Chevaliers, one of the largest castles in the Holy Land, had a garrison of roughly 2,000 men strong.

Flint Castle, a rather small castle built in 1284, part of Edward I's Welsh castles, had a garrison 120 men strong at its peak.

Resources: Fantasy Demographics
Autarch's Adventurer Conqueror King Alex has a blog post "The Demographics of Heroism" about assumptions of how rare individuals are leveled from 1st to 14th level.
The Magic Tree Tanz deconstructs how many hypothetical NPCs would have "the hero stuff" and survive long enough to do something with their class levels.
The Fifty Percent Rule MontyWild proposed a 50% rule for determining how many NPCs of a given level appear in a world. Not an unreasonable starting point.
D&D vs. USA Demographics Fallencoder does an interesting comparison of adventurers to US armed forces personnel, coming up with probabilities of encounter an NPC of #th level in the world, and in a number of combats. Possibly flawed assumptions, but interesting nevertheless.

 

[Quickleaf]

Step 5: Making Monsters (part 1 – NPCs)

My next step has been to design and convert a whole lot of monsters/NPCs, and not just stat blocks, but to come up with an interesting role for them within the adventure/dungeon. I could absolutely do this later on, but I like knowing the capabilities of the creatures inhabiting the dungeon; I feel that gives me a consistent way to figure out how they can respond to the PCs and how they might creatively employ their abilities given their environment.

This means having a list of monsters that are thematically appropriate for your dungeon. I already had that early on, but if I didn't I would compose it now. Here's my list, though note that this is the latest version and it underwent a couple changes (e.g. I cut out flame horrors since they inhibit fire magic, I replaced the horned devil gate guards with maelephants, and in many cases I wasn't sure on the CR until I'd done a bit of design).

One important guideline for this step is variety. This means a variety of monster types (e.g. celestial, fiend, giant, humanoid, monstrosity, etc); this is relevant for the ranger's Favored Enemy, for magic items referencing specific monsters, for a few spells, and just to keep the players on their toes. It also means a variety of CRs, since a good dungeon/adventure throws combats of varying difficulties at the PCs. And it means thinking towards ways you can use the same set of monsters in creatively different situations (both in and outside of combat).

Spoiler: My list of monsters

New Monsters
The Bonfire CR ?
Maelephant CR 12
Tasked Genie, Guardian CR 12
Tasked Genie, Slayer CR 11
Fire Elemental Monolith CR 11
Great Ghul CR 10
Immolith CR 9
Khaz’harakhi CR 9
Angel, Asuras CR 8
Agha of the Imperishable CR 6
Dune Stalker CR 6
Priest of Kossuth CR 6
Shig’harakhi CR 6
Skeleton, Blazing CR 6
Cinderhaunt CR 5
Disciple of the Salamander CR 5
Hellcat CR 5
Flamedeath Fedayeen CR 4
Genie, Janni CR 4
Swarm of Fire Bats CR 4
Mamluk of the Imperishable CR 2
Fire Bat CR 1/4

Monster Variants
Pyrohydra (hydra) CR 11
Black Flame Zealot (asssassin) CR 9
Shadow Wyvern (wyvern) CR 9
Desert Terror (bulette) CR 8
Al-Mazhar Fire Elemental (elemental) CR 6
Desert Troll (troll) CR 5
Elder Flameskull (flameskull) CR 5
Copper Automaton (helmed horror) CR 4
Fire Scorpion (giant scorpion) CR 4
Kada, Dark Reflection (shadow demon)
Crypt Servant (wight) CR 3
Lesser Ghul (ghast) CR 3
Witherweed (awakened shrub) CR ?

Monster Manual
Iron Golem CR 16
Purple Worm CR 15
Erinyes CR 12
Remorhaz CR 11
Oni CR 7
Mummy CR 3
Cult Fanatic CR 2
Cultist CR 1/8
Guard CR 1/8
Commoner CR 0

For the first part, I'm going to focus on designing NPCs, since I keep seeing the question of NPC design spring up online. To clear up any misconceptions:

NPCs in 5th edition are NOT created using the Player's Handbook.

And the "level" of an NPC (whether you determine that by their Hit Dice or spellcasting level) does NOT determine their CR.

You determine CR the hard way using the guidelines in the Dungeon Master's Guide pages 273-283. Period.

That said, there's nothing wrong with doing an "inspired by class X" NPC, you just need to be thoughtful about which class features you include. For example, adding Thieves Cant as a language or interpreting Extra Attack as Multiattack is easy. However, you'll have to think hard whether it's worth it to include features like Reckless Attack or Evasion, or whether that space is better spent on something more unique to the NPC (or just cut out entirely).

I'll use the Priest of Kossuth as my example. Think this guy:

The Priests of Kossuth, of which there are five inhabiting Krak al-Mazhar, oversee ritual purifications, initiation of acolytes into the Temple of Kossuth, binding of fire elementals, administering of the magical flames of truth when justice is required, and overseeing extracting of the waters of life from the dead. Their alignment is Lawful Neutral or Lawful Evil. I'm imagining them having the spellcasting ability of a 10th level cleric; why 10th? So they can cast conjure elemental and flame strike, baby! Also, I like the old school aesthetic of NPCs with strongholds being of 9th level and higher. I see these priests as managing one of The Bonfire's biggest power bases – the faithful of Kossuth – and so he has to be wary of their political power within the Brotherhood.

Nothing else really catches my eye from the cleric, so I think I'll give the priest 2-4 new features/traits to distinguish it from the priesthood of any other deity.

For starters, I know the priest will have damage resistance to fire. I've read they're called "Firewalkers" and I'm imagining them being able to move through ongoing flames without being scathed as an act of concentration. So maybe that's their first new trait....

Firewalker. The priest of Kossuth can concentrate as a bonus action to gain immunity to non-magical fires (including the Plane of Fire); during this time it has advantage on its saving throws against fire-based magic.

Next, I know these guys are going to be the major summoners of Krak al-Mazhar, and they need to be scarier than the standard spellcaster conjuring an elemental whose concentration is easily broken. So I think there's their second new trait...

Kossuth’s Summoning #1. Fire elemental creatures summoned by the priest are at maximum hit points. If summoned within sight of a shrine of Kossuth, the priest does not need to concentrate to maintain the summoning. If the priest is killed or knocked unconscious, summoned elementals go berserk.

Simple enough, though it does makes the situation a bit black-and-white. The only way to get rid of the elemental is banishing it, or killing it or the priest. Moreover, conjure elemental still requires 1 minute! So they can't do this in the heat of battle. Hmm...maybe I can come up with a more interesting alternative...

Kossuth's Summoning #2. The casting time for the priest's conjure elemental and conjure minor elementals is just one action, instead of 1 minute. When the priest loses concentration on the spell, the elementals don’t disappear or turn hostile but instead behave erratically as if under confusion. The priest may reassert its control over elementals it can see as an action, resuming concentration.

This makes the priest much scarier – they can summon a fire elemental in combat! – but also is interesting in that you don't know exactly what will happen when disrupting the priest's concentration...only that you've got a limited window to take the priest down before it reestablishes control of the elemental.

OK, let me think about their spell list next... Mostly going to limit myself to cleric spells, but not being strict about it because conjuring elementals is the priest's schtick, and conjure elemental is most definitely not a cleric spell. Fire is associated with purification and rebirth, the flame of truth (owing to an old story about placing a coal in the liar's mouth perhaps). I've also noticed that Kossuth's favored weapon is the spiked chain, so that gives me an idea about how these priests might adapt flame blade. I think I have enough to go on here...

Spellcasting. The priest of Kossuth is a 10th level spellcaster. Its spellcasting ability is Wisdom (spell save DC 14, +6 to hit with spell attacks). It has the following spells prepared (EE means Elemental Evil Player's Companion, * indicates a new spell:

Cantrips: control flames (EE), light, sacred flame, thaumaturgy
1st level (4 slots): burning hands, cure wounds, fire truth*
2nd level (3 slots): continual flame, flame blade (can be cast with a 3rd level slot to use flame whip), lesser restoration
3rd level (3 slots): dispel magic, protection from energy, revivify
4th level (3 slots): conjure minor elementals (fire only), guardian of faith
5th level (2 slots): conjure elemental (fire only), flame strike

So, now I need to figure out what flame whip does. Going to go with the most simple adaptation...

Flame Whip. Melee Spell Attack: +6 to hit, reach 10 ft., one target. Hit: 10 (3d6) fire damage, and the priest slides the target 5 feet in a direction of the priest’s choosing.

This has some nice interplay with the guardian of faith spell and any fire hazards the priest might be encountered with.

Pretty good. Last thing I want to give them is kind of a roleplaying thing I've been thinking about, like a fire charm which transfixes creatures staring into it. The priests may or may not ever use it on the PCs, but it goes a long way towards the DM grasping their feel and how they might interact with other NPCs if the PCs are watching.

Channel Divinity: Fire Charm (recharge short rest). A normal fire source within 60 feet of the priest emits a gossamer veil and alluring whispers. Any creatures of the priest’s choosing observing the fire must make a DC 14 Wisdom saving throw or be charmed into remaining motionless and gazing transfixed at the flames. All saving throws made while the creature is charmed have disadvantage. The Fire Charm is broken by attacking the charmed creature, if their line of sight to the fire source is obstructed, if the fire source is extinguished, or after 1 minute passes.

Here's what I've got so far, along with the priest's estimated CR.

Last step is to calculate the CR, referencing DMG p. 273-283.

Defense is easy - the priest is defensively weak. HP 65, AC 14. So defensive CR 1/2. I may want to raise the Dexterity to 12 (+1), to boost their AC to 15 and hence CR to 1. We'll see.

Offense. First step is figuring out the priest's DPR (damage per round); as is the cast with many spellcasters this requires visualizing 3-rounds worth of actions and calculating all damage from there. For the purposes of CR calculation, I'm going to assume the priest casts flame strike twice. In reality, these guys are going to use one 5th-level slot to summon a fire elemental, but calculating offensive CR is all about maximizing damage output; besides, the fire elemental will surely be doing damage as well.

Round 1: guardian of the faith, it hits two creatures for 40 damage total
Round 2: guardian of faith hits its last target for 20 damage. flame strike, I'm assuming it targets two creatures (using DMG p. 249 "Targets in Area of Effect" as my guideline), so that's 28 (8d6) * 2, which is 56 damage. 76 damage total.
Round 3: flame strike, I'm assuming it targets two creatures (using DMG p. 249 "Targets in Area of Effect" as my guideline), so that's 28 (8d6) * 2, which is 56 damage.

Damage per round = (40+76+56) / 3 = 57

So that puts their offensive CR at 9. With a save DC of 14, that reduces its offensive CR one step to 8.

And (8 + 1/2) / 2 = CR 4.25

Hmm. That's a little lower than I'd like for these priests, and also I realized that I didn't calculate burning hands, which is OK because I'm thinking is probably better to leave out and reserve for the wizardly NPC types. Also, I'd like to incorporate some way for the priest to summon another monster I'm going to create: a fire elemental monolith (~CR 11).

So here's what I'm going to do:

• Increase the priest to being a 12th-level caster with 12+24 HD (78 hp).
• Replace burning hands with detect evil and good (which helps them suss out hidden fire elementals as well as a celestial NPC who has had altercations with the Brotherhood in the past).
• Turn fire charm into a "new" 4th level spell, instead of a special ability (it used to be an AD&D spell).
• Give it the spare the dying cantrip and sanctuary 1st-level spell.
• Give it a spiked chain melee attack.
• Boost Dexterity to 12 (+1), which boosts their AC to 15. Together with its HP of , that gives it a defensive CR of 2.
• Boost Wisdom to 18 (4), increasing its spell save DC.
• And I'll give the priest planar ally as its 6th level spell.
• Lastly, I'm going to add a sidebar about priests of Kossuth summoning & binding more powerful elementals as a group.

It's definitely a CR 5, and I'm going to judge it as a CR 6 because of its really awesome summoning capabilities and the possibility of dropping a third flame strike using its 6th-level spell slot.

And here's the (probably) final version!

 

[Quickleaf]

Step 5: Making Monsters (part 2 – Monster Variants)

Before I get into full-blown monster design/conversion, I wanted to point out something that can be easy for us DMs to forget. There are lots of ways to re-skin a monster or tweak it slightly to give it an entirely different feel. Not only does this save on work / page count, but it makes it easier on you as DM because you're working with a known quantity as the baseline. "It's a goblin, but it throws fire bombs" makes it easy for a DM who already knows how a goblin runs (and I mean runs quite literally ).

First, an example of re-skinning. Take Mummies. They're spooky, not terribly bright, malevolent, and usually have semi-tragic backstories. PCs quickly learn that they're best dealt with by either (a) not waking them from their sarcophagi, or (b) with lots of fire from a distance to avoid their rotting touch. Instead, I wanted to play up the role of mummies as archivists, so I have some of the original mystics (before they were corrupted into the Brotherhood of True Flame) as Lawful Neutral mummies watching over one area of the dungeon. The Bonfire (BBEG) occasionally has one summoned up to try to glean ancient secrets from its riddling raspy mouth. These aren't mummies you fight, not really - they're mummies that tell a story and you can interact with, and maybe even make some kind of tentative truce with. That's a big change in feel that was accomplished without changing any stats (except alignment).

OK, now for a meatier example. Elder Flameskulls.

I want to make the scope & stakes of this dungeon big, appropriate for 15th-16th level PCs. And one way I want to do that is by dropping the names of famous D&D pyromancers and insinuating that they may have had connections with the Brotherhood. This includes Aganazzar, Abi-Dalzim, and Daltim (who conveniently have names that fit the pseudo-Arabian vibe I'm going for). As I was brainstorming, I realized that they would be perfect as some kind of "burning undead" monsters guarding various key areas/zones of the citadel. While I'm converting blazing skeletons and creating cinderhaunts, neither of those quite were what I was looking for. And then it hit me: Flameskulls can be really hard to truly kill due to their Rejuvenation. Of course holy water/remove curse/dispel magic are simple for high-level PCs, so I'll need to make it more challenging to counter their Rejuvenation...maybe with unique conditions.

I also want to distinguish the character and signature spells of these three D&D wizards (i.e. The obsessively focused Aganazzar with aganazzar's scorcher, the wicked and envious Abi-Dalzim with abi-dalzim's horrid wilting, and the mad conjurer Daltim with daltim's fiery tentacles).

So what does this look like?

I re-worked the monster math, but didn't save it and don't feel like rewriting, so you'll just have to trust me.

OK, that was a cool example, but I knew going into it that I was going to base the monster on the Flameskull. What if it's not so clear? Well I started off thinking I would convert the Copper Automaton as a new monster; it is described over on the Forgotten Realms Wikiw and is called out in a few places as a servant construct of the Brotherhood of True Flame.

However, when I began reading its old AD&D stats, I realized that its only real unique trait was that its weapon grew hotter and hotter as it fought. And that's it – the entire mechanical premise of the monster, besides being a construct, was that one trait. There's mention of it being healed by having mechanical work done on it, but in 5e that's kind of built into the mending cantrip (which seems to entirely heal constructs after 10 minutes). So I wondered if I could instead just add a trait to an existing construct.

And that's when it hit me. Helmed Horrors are virtually identical to Copper Automatons; heck, in AD&D they have comparable Hit Dice, AC, and attacks/damage.

Thinking more on it, I decided to appropriate the Iron Golem's Fire Absorption trait and use it here; since the Copper Automaton is associated with the Brotherhood of True Flame, it makes sense that it would be designed to be healed by fire. And that led me to this...

That's just a few examples of how you can leverage existing monsters and re-skin or slightly tweak them to create a monster with an entirely different feel in the narrative of your adventure/dungeon.

 

[Quickleaf]

Step 5: Making Monsters (part 3 – Converted & New Monsters)

A lot of times when I get an idea for an adventure or dungeon, there will at least be a one monster I have in mind that either isn't in 5th edition yet or is something I've imagined and haven't seen in D&D before. In these cases, I first double check to make sure that there isn't an existing monster I can easily re-skin or tweak to get what I want; if not, then I move into the monster design process.

The monster I'm going to convert here is the Dune Stalker from the AD&D Fiend Folio. I'm reading in DUNGEON #63's Blood and Fire adventure how they're used by the Brotherhood of True Flame, and they really fit the theme I'm going for, so let's do this!

Since it's a monster that's not recognizable to D&D fans, and frankly it's new to me too (a "desert" equivalent of an invisible stalker? who knew!), so I'm going to start with the prose...

[SECTION]Dune Stalker
Hailing from the Fountains of Creation (also known as the Plane of Magma), a dune stalker is a hideous 7-foot tall creature that appears as a combination of devolved human and reptilian horror with long arms, an avoid skull, and large black eyes. Its rust-colored skin serves as a natural camouflage in deserts, dry hills, and similar terrain.
Directed Hunter. When summoned to the Material Plane, a dune stalker only obeys those summons involving hunting down and slaying a specific creature or recovering an object. Any other request frees it from the summons, allowing it to return to the Inner Planes, though it may decide to take the summoner along with it for a snack. Otherwise, it pursues the task until completion, then returns to its summoner for further commands. If its summoner dies, the dune stalker returns to the Inner Planes upon completing its task.
However, a dune stalker is an unwilling servant at best and resents any commands given to it. A task that involves a great deal of time might lead the frustrated dune stalker to pervent the intent unless the summoner worded it very carefully.
Maliciously Literal. Dune stalkers take their commands in the most literal manner possible, looking for loopholes that allow them to indulge their vile natures hunting the defenseless and avenging themselves on mages.
Tone Deaf. The structure of a dune stalker’s skull and ear canal prevent it from hearing sounds in the normal range of human hearing. On the other hand, it can hear high-pitched sounds (e.g. breaking glass, a baby crying, a mosquito, a dog whistle) as well as low-pitched sounds (e.g. the beating of a drum, sounds made by a crocodile or elephant, or the rumbling of a distant storm or volcano).
Waterless Anatomy. A dune stalker has no need of water. Its body is so devoid of water that it doesn’t sweat, its bones are made of incredibly dense tubes spiraling around one another to make a strong lattice, and its skin is like a blend of sun-dried leather and highly abrasive sandpaper. Any degree of humidity causes the dune stalker extreme discomfort, and exposure to water will repel it for a time being.[/SECTION]

Obviously these guys have the Faultless Tracker trait of the invisible stalker (and similar resistances & immunities). Another trait easily applied to them is Desert Camouflage (adv. to Stealth in desert).

That leaves two distinct things: its Sonic Ray & its "Kiss of Death."

The Sonic Ray is basically a breath weapon doing thunder damage and causing deafness. In 1e it was a single target attack, while in 2e it became a cone. Hmm. Kind of boring. It would fit for a dragon, but it feels weird for a magically conjured assassin. Our assassins impose...deafness! Wait, really? So I'm going to reimagine this ability as something both disorienting and enduring, that provides creative options for PCs to counter it...

[SECTION]Sonic Ray (recharge 5-6). The stalker emits a 60-foot line of sonic energy from its mouth. Each creature caught in the line must make a DC 14 Constitution saving throw or take 13 (2d12) thunder damage and be deafened until the end of their next turn. While deafened, if the target tries to move it must make a DC 14 Wisdom saving throw or end up moving its speed in a random direction (determined using a d8). The stalker can concentrate to maintain this line of sonic energy to one creature that failed its Constitution saving throw; at the start of each of the dune stalker’s turns that creature automatically takes 13 (2d12) thunder damage and remains deafened. The sonic effect can be canceled by a bard’s countersong, the target gaining at least three-quarters cover, or an ally voluntarily stepping between the target and the stalker - immediately becoming the new target.[/SECTION]

So this allows the stalker to throw a group into a bit of chaos while singling out their target. And the vibe is a bit more like those specters from Harry Potter and the Deathly Hallows that suck your soul – only this is like waves of sonic energy emanating from the dune stalker. Fun fun fun.

Now, "Kiss of Death" is a save or die effect in AD&D. So I'll look to something like the 5e banshee for inspiration (it can reduce a creature to 0 hp so they begin dying, but doesn't kill outright). Also, even though it's described as a close contact attack, if you look at the 5e succubus's Draining Kiss, that requires a willing or charmed target. The dune stalker is basically putting its face against the target's face, so I'm thinking there needs to be a limitation on who Kiss of Death will effect – incapacitated or deafened by the dune stalker (and thus disoriented) seem like good options.

[SECTION]Kiss of Death. If the stalker uses Sonic Ray against a creature within 5 feet that is incapacitated or deafened by the stalker, and the creature fails its Constitution saving throw, the creature is reduced to 0 hit points; if the creature is already at 0 hit points it instead suffers two death saving throws failures. Even if the creature succeeds its Constitution save, it is still affected by the Sonic Ray as normal.[/SECTION]

OK, I think I can put the Dune Stalker together now...

[SBLOCK=Monster Maths: Dune Stalker]
Defensive CR: HP 120, but with damage resistances (that means bludgeoning/piercing/slashing) for an expected CR 5-10, so I apply a *1.5 modifier, getting 180 effective HP. Which is CR 8, which the chart says should be AC 16. And hey, that's the Dune Stalker's AC exactly, so we're done here. In fact, if its AC had been 15 or 17 we'd still be done.

Offensive CR: Because this monster has limited use abilities (i.e. it's not doing exactly the same thing every round), I need to plot out a 3-round course of actions. In this case, I'm leaving Kiss of Death out of it due to the conditions required to set it up, but that's totally in the back of my mind...for example if it's final calculated CR was 5.25 or something, I'd be inclined to round up due to Kiss of Death. And that's a good trick to know when you're doing the maths for your own monsters and have a trait/ability you don't know how to "value" in the CR system – just save it till the end and guesstimate. That's part of the art of monster design.

Round 1 – Sonic Ray (acc. to DMG p. 249 it's safe to assume a 60-ft line hits 2 targets) = 2 * 13 = 26
Round 2 – concentrates to maintain Sonic Ray, 2 claw attacks = 13 + 2 * 7.5 = 28
Round 3 – 2 claw attacks = 2 * 7.5 = 15

DPR = (26 + 28 +15 ) / 3 = 69 / 3 = 23

That's CR 3, which the chart tells us should expect to have +4 attack, but since the Dune Stalker has +6, we bump that up to CR 4.

So, (8+4)/2 = CR 6. [/SBLOCK]

Next, I'm going to create a pretty much brand new monster for this adventure/dungeon: the Cinderhaunt. Mortal creatures who are destroyed by the Plane of Fire (or by flame mages channeling its power) may arise as cinderhaunts if their hearts burn with some unfulfilled yearning. The Cinder Wastes predominating the Plane of Fire are filled with such spirits wandering amidst the ruins of forgotten civilizations. Cinderhaunts look akin to their form in life, but their skin appears made of ash through which cracks of angry flame show. Plumes of smoke and ash trail behind a cinderhaunt when it walks.

This idea has been tackled before in various ways, and I'm sure that some Pathfinder book has a "burning undead" out there that might fit. I'll try to find a couple pictures to triangulate the idea for the Cinderhaunt...

Cinder Ghoul (Tome of Horrors Complete, Swords & Wizardry)

Flaming Zombie (video game?)

Soul of Cinder (Dark Souls 3)

The first question I'm going to ask is: Why do I need this monster for this adventure/dungeon?

1. First, I'm imagining The Bonfire (BBEG) will have a legendary or lair action to create Cinderhaunts from adventurers he slays. And other folks too, it's just adventurers tend to have the unfulfilled yearnings thing.
2. Second, they speak to the semi-tragic backstory of the Brotherhood and exemplify its wickedness, driving home to the PCs just how dastardly the villains are.
3. Third, they present an elusive soldier-type enemy that serves as a unique challenge unlike other monsters in Krak al-Mazhar, especially unlike the other "burning dead" (e.g. flameskulls & blazing skeletons) who are more about artillery.

Next I tackle my prose write-up. This is a really important step in creating a monster, especially when creating a new monster.

[SECTION] Mortal creatures who are destroyed by the Plane of Fire (or by flame mages channeling its power) may arise as cinderhaunts if their hearts burn with some unfulfilled yearning. The Cinder Wastes predominating the Plane of Fire are filled with such spirits wandering amidst the ruins of forgotten civilizations. Cinderhaunts look akin to their form in life, but their skin appears made of ash through which cracks of angry flame show. Plumes of smoke and ash trail behind a cinderhaunt when it walks.
Fire Eaters. While a cinderhaunt usually only vaguely recalls its living purpose, it still burns with passion. Unless it feeds on heat regularly, a cinderhaunt will eventually consume itself with its inner fire. In particular, the heat of the living draws a cinderhaunt far more than a simple campfire, and thus they are drawn to battlefields where flaming oil or fire magic has been used as a devastating weapon, sites of impassioned arson, or places where witches or traitors were burned at the stake.
Supernatural Echoes. When a cinderhaunt occupies a place, the cinders and ash falling from its body cause eerie magical effects. An adventurer kicking up a small pile of dust hears a ghostly hissing sound or glimpse a fleeting skull appear in the dust. Sparks from a torch carry further into a tomb, kept alight far longer than expected, even as the torch burns down faster faster than it should.
Unfilled Yearning. A fire burns in the chest of every cinderhaunt far exceeding normal human passions. This need is twisted to becoming the single driving force animating a cinderhaunt’s corpse.

Unfulfilled Yearning (d6)

1. Completing a quest
2. Leaving a legacy
3. Prestige and praise
4. Revenge
5. Treasures untold
6. Unrequited love

[/SECTION]

With their story/flavor developed, I start to brainstorm traits/actions for the Cinderhaunt...

These are hard creatures to kill permanently, so I'm giving them Regeneration similar to a troll...probably countered by cold instead of fire (i.e. freezing over their yearnings)... and since cold is a rarer damage type I'll add some condition to their Regen...maybe they need ashes/cinders nearby to draw upon to regenerate.

They drain heat, so some kind of a cold aura...maybe one that also denies bonus actions and/or reactions to reflect the sort of limb stiffness / mind slowness inflicted by numbing cold. That also makes them more suited to front-line fighting, which is something the Brotherhood needs.

They can assume a Smoke Form as an action, similar to gaseous form of a vampire, and is basically harmless / can't be harmed in this form. Except for cold. If it gets hit by cold damage, it is forced to revert to its true form.

Related, they can discorporate and reappear somewhere else in a burst of cinders. This is a little different from normal teleporting (e.g. from a yugoloth's Teleport action) in that it only works intermittently (i.e. recharge 5-6) and the Cinderhaunt has the option of reappearing at the start of its next turn or immediately teleporting. My inclination is to make this a move option. In the multi-leveled Krak al-Mazhar this means that just because you see a Cinderhaunt down a level below or above you doesn't mean you're safe. Sparks burst and suddenly it rises from the floor before you or steps out of a decaying tapestry.

Lastly, its attacks. Since I'm gauging this monster as being equal to or mightier than a Wraith in terms of Challenge Rating (CR 5+), I'm guessing it needs a Multiattack. I think two different attacks would be interesting: a Smoking Sword (which may blind) and a Desiccating Touch (which may reduce maximum hit points).

Next, I use my benchmark (the Wraith, 9d8+27) to guesstimate hit dice. This is mostly a corporeal undead so no need for extensive damage resistances. And definitely a frontline fighter, so probably a bit more hit dice. I'm going with 11 because I'm imagining Cinderhaunts as being the souls of adventuring sorts with strong passions/beliefs (i.e. in the 11th-16th level tier). So I'm thinking 82 (11d8+33) is a good starting point.

Now is a good time to figure out its ability scores. Generally I'm thinking they're pretty high...
Str 16 (+3) It's a fighter type
Dex 17 (+3) It knows how to use its Smoky Form in the midst of combat
Con 16 (+3) Life amidst the flames has hardened it
Int 12 (+1) Canny strategist who has existed a long time in undeath
Wis 14 (+2) Canny strategist who has existed a long time in undeath
Charisma 18 (+4) Very strong force of personality to hang onto its yearnings even in undeath

I think that's enough to put the Cinderhaunt together...

[SBLOCK=Monster Maths: Cinderhaunt]
Defensive CR: I always start with calculating defensive CR because it's (usually) easier. Here we have 82 HP, but with Regeneration bumping its effective HP to 112. That's CR 3, and chart says its AC should be 13. Actual AC is 14. So I'm good....or am I? My sense is that Smoky Form and Discorporate contribute to the monster's defensive capacity enough to be worth +1 or +2 AC. So I'm valuing its Defensive CR at closer to 4.

Offensive CR: This one is easy because it does the same thing each round. Aura Damage (assuming to at least one PC, that's 9), Smoking Sword (8.5 + 13.5), Desiccating Touch (21), which is 52 damage. That's CR 8, which charts says should have attack +7, which is the Cinderhaunt's attack exactly. I'm good here.

(4+8)/2 = CR 6

So I actually misrecorded the Cinderhaunt's CR. It's actually a CR 6, not CR 5. Good thing I ran these numbers![/SBLOCK]

[SECTION]Resources: Monster Design
AngryGM has a good article covering 5th edition monster creation in detail, starting from the very basics[/SECTION]

 

[transtemporal]

I really like your approach, very cool. I particularly like how you're consciously accounting for "x-level" spells and certain abilities like turn undead. Part of the bane of high level adventures is planning encounters when the PCs can just fly or teleport around them.

One thing though. Correct me if I'm wrong, but doesn't Krak al-Mazhar kinda roughly translate to "Castle of the Tambourine"?

 

[Quickleaf]

I really like your approach, very cool. I particularly like how you're consciously accounting for "x-level" spells and certain abilities like turn undead. Part of the bane of high level adventures is planning encounters when the PCs can just fly or teleport around them.

One thing though. Correct me if I'm wrong, but doesn't Krak al-Mazhar kinda roughly translate to "Castle of the Tambourine"?

Beware the fearsome tambourine Haha, well my understanding is that "al-mazhar" derives from a Quranic term meaning "the divine manifestation." But I guess tambourines can be almost as divine as well-played cow bell, so...

Back to serious gaming seriousness!

Yes, flying and teleporting are two things I've considered strongly in this adventure. There are a host of other spells I need to think about too...for example, passwall might let them skip right to the BBEG's lair unless I arrange the layout so his "tower" is toward the center of the complex...or design a highly adaptive adventure which can accommodate bopping right into the BBEG's bedchamber. I'm inclined to do a little bit of the former, and a lot of the latter.

For flying – it can help access certain areas, yes, but since the citadel is carved into the stoney caldera ridge, there are some areas that are flat out inaccessible by flight. Because rock.

For teleporting – there's blanket forbiddance spell over most of the citadel that prevents teleporting. I usually avoid such methods of "red lighting" player abilities, but in this case it fit both the BBEG's abilities, personality, and modus operandi. When it fits, it fits!

 

[Quickleaf]

Step 5: Making Monsters (part 4 – Hard-to-Convert Monsters)

So far the monsters I've converted have been straight forward or taken a bit of creative thinking. However, every now and then you will find an old monster (or invent a monster of your own) with some trait or action or concept that just won't translate well into existing game terms. That's when it gets really interesting.

In this case, I'm converting the Maelephant, a large pachyderm-headed guardian fiend who breathes gas that induces total memory loss. And the memory loss is the sticky wicket.

I'm planning to use some of them as guardians of Krak al-Mazhar bound by The Bonfire or his predecessors. More on how I'll be using them later...

I'm going to start by looking at possible comparisons: modify memory and feeblemind (which also happens to be the effects of the River Styx, acc. to the DMG). Modify memory isn't strong enough for what I'm looking for. However, feeblemind is weird...

On a failed save, the creature’s Intelligence and Charisma scores become 1. The creature can’t cast spells, activate magic items, understand language, or communicate in any intelligible way. The creature can, however, identify its friends, follow them, and even protect them.

It makes you an idiot, essentially, strips you of your communication ability, strips away spellcasting but.... if you have Extra Attack or other class abilities or proficiency with a poisoner's kit you can still use those just fine... and you still remember who your friends are. Feeblemind doesn't feel like a good fit either, but it's moving in the right direction.

However, what I have been able to gauge is that the maelephant is able to use an ability which allows it to kind-of-but-not-feeblemind a group of creatures. By comparison, a PC would only get the ability to feeblemind one creature at around 15th level (when a full caster would gain 8th level spells). Something to think about when establishing the maelephant's CR.

Challenge Rating
In fact, I'm going to do this right now. It's something I usually have in the back of my head when converting monsters – a rough estimate of the target CR I'm aiming for. To do this, I generally look at the monster across a couple editions of D&D and also compare it to another monster of approximately similar power level that is already in 5e's Monster Manual (or Volo's Guide). Generally I look at XP value, Hit Dice, and any CR ratings.

There are two versions of the maelephant for me to compare: AD&D PLANESCAPE and the 3e Fiend Folio. And for comparison, I'm going to look at the AD&D, d20, and 5e versions of the horned devil (cornugon...renamed to malebranche in 5e).

EDIT: Tables apparently don't work on ENWorld anymore?

AD&D Maelephant: 8+2 HD; 10,000 XP
3e Maelephant: 8d8+24 HD; CR 10

AD&D Horned Devil: 10 HD; 10,000 XP
3e Horned Devil: 15d8+105 HD; CR 16
5e Horned Devil: 17d10+55 HD; CR 11 (7,200 XP)

What this reveals is that horned devils got a major power-up in 3e that maelephants did not. Why? Well besides having a boatload of hit points, they had damage reduction, regeneration, could invoke fear and shoot a lightning bolt, could stun with their spiked chain, and delivered a really nasty ongoing wound that could only be stopped by a DC 24 Heal check, a cure spell, or a heal spell (and the caster had to make a DC 24 caster level check!).

5e reined the horned devil's power back to closer to AD&D levels. What we see in AD&D is that even though the horned devil is a tougher in a physical fight, the maelephant is worth the same amount of XP. Why? I have two theories: blade barrier 3/day and it's memory-wiping breath weapon (trunk weapon?).

So my target for the maelephant is going to be somewhere around CR 10 – 12. Definitely CR 9+, because CR 9 is meant to be a medium challenge for a 9th level party, and a 9th level party could have access to greater restoration...which is the first spell that can restore memories lost to a maelephant.

The Tricky Ability: Memory-Wiping Breath Weapon
Both AD&D and 3e list this as 3/day; which is the same as what AD&D dragons get for their breath weapon, so I'm going to make it a recharge (5-6).

In AD&D and 3e it's 10’ wide and 30’ long. So I'm going to make that a 30-foot cone in 5e terms.

The AD&D saving throw is vs. poison, and in 3e it's vs. Fortitude. Instead, I'm going to require an Intelligence save because (a) it matches up with Feeblemind & the Enchanter's 14th level Alter Memories feature, and (b) there need to be more Intelligence saves in the game!

Next, thinking about memory loss, that's like a devastating event for a PC. Right up there with petrification maybe. So I'm going to look to how the medusa works; the first failed save vs. her Petrifying Gaze means you're restrained and starting to turn to stone (unless you fail by 5+, in which case you're screwed), and then if you fail your second save you actually turn to stone. I'm going to mimic that.

[SECTION]Breath Weapon (recharge 5-6). The maelephant exhales a cloud of noxious gas inducing memory loss in a 30-foot cone. Creatures caught in the gas must make a DC 14 Intelligence saving throw. If the saving throw fails by 5 or more, the creature instantly suffers total memory loss. Otherwise, a creature that fails its save begins to lose its memories, losing concentration on any spells and becoming incapacitated. The incapacitated creature must repeat the saving throw at the end of its next turn, suffering total memory loss on a failure or ending the effect on a success. The memory loss lasts until the creature is freed by the greater restoration spell or other magic....[/SECTION]

So that's half the write-up. Now I need to define what "total memory loss" means in game terms. AD&D is vague of course, but the 3e maelephant has some clues....

Memory loss suppresses all of a creature’s ranks in its skills and its feats, and it prevents the use of any class abilities (including spellcasting). Currently prepared spells are not lost; they are simply not accessible to be cast. Racial abilities are retained. Additionally, the victim no longer knows who its friends and enemies are, doesn’t remember its past, and can’t even remember its name.

What I like about this is that it doesn't touch the PC's language capacities or ability scores (like 5e's feeblemind). Losing your class abilities sucks enough, no need to make the PC unable to communicate whatsoever. In 5e terms, I might translate this as...

[SECTION]A creature creature suffering total memory loss no longer applies their proficiency bonus to any rolls, loses all class features including spellcasting, and is unable to recall friends and enemies, past events, even its own name. However, the creature retains the ability to speak, read, and write its dominant language. The memory loss lasts until the creature is freed by the greater restoration spell or other magic.[/SECTION]

Wordy, but that does the job nicely!

Other Abilities

With the hard part done, I move onto the other abilities of the maelephant, listing them out:

• Frenzied Charge = the Charge ability on many monsters in the 5e MM
• True seeing at will = Truesight in 5e
• Spellcasting (at-will: alarm, bind, entangle, gust of wind, light, true seeing, warp wood; 3/day: blade barrier, polymorph other) = 5e Innate Spellcasting (at-will: alarm, entangle, gust of wind, light; 3/day each: blade barrier, polymorph - others only)
• Never surprised & Keen senses alternately described as hearing/smell or sight = well, that feels a bit redundant with Truesight, elephants lack Keen Senses, so I'm just going to go with double proficiency bonus to Perception (I seem to remember other AD&D "never surprised" monsters receiving Expertise in Perception in the 5e MM)
• Immune to attack from nonmagical weapons, or DR 20/+1 = 5e resistance to bludgeoning, piercing, and slashing from nonmagical weapons
• Auto-damage grapple, Improved Grab = auto-grapple attack with ongoing damage if creature ends its turn grappled
• AD&D mentions that they never make morale checks when guarding (which is significant in that they bothered mentioning that for a creature of already fearless morale), though 3e makes no mention of it = I'm including to give them immunity to the frightened condition, along with immunity to memory loss
• 3e's Defensive Stance (1/encounter, free action, dodge bonus to AC and saves, STR and CON) = a boosted Dodge action option granting advantage to all saves (yah for concentrating on blade barrier!), and opportunity attacks don't require expending a reaction while dodging
• Regeneration / Fast Healing I cut this one because the Horned Devil had 2 hp/round regeneration in AD&D (like the maelephant) but doesn't in 5e. Seem like it wasn't an iconic ability or wasn't potent enough to warrant inclusion, so I'm following suit for the maelephant.

Ability Scores
I'll compare the AD&D and 3e versions of the maelephant, along with the 5e horned devil, and 5e elephant for good measure.

AD&D Maelephant: Strength (a -5 Str penalty to a victim's escape check implies it may be 20-21), Constitution (a +2 HD modifier, suggests it may be 14-15), Intelligence 13-14
3e Maelephant: Strength 22, Dexterity 11, Constitution 16, Intelligence 14, Wisdom 19, Charisma 15
5e Horned Devil: Strength 22, Dexterity 17, Constitution 21, Intelligence 12, Wisdom 16, Charisma 17
5e Elephant: Strength 22, Dexterity 9, Constitution 17, Intelligence 3, Wisdom 11, Charisma 6

So, triangulating its ability scores from that information, I end up going with precisely its 3e stats.

Saves & Skills
Looking at its 3e stats: Concentration skill and Iron Will stand out to me. I translate these as Constitution and Wisdom saving throws. Strength also makes sense to me, judging from the art. And "an elephant never forgets" so I'm give it Intelligence saves too. Why not. This also mirrors the Horned Devil's 4 proficient saves.

For skills, definitely double prof. in Perception. Let's see...its 3e stats also highlight a high Sense Motive and Spellcraft! So maybe regular prof. in Insight and Arcana.

Hit Dice, AC, and Other Stuff

I'm taking an educated gamble when it comes to reaching its Hit Dice. The Horned Devil, remember him? Went from 10 HD in AD&D to 17 HD in 5e. That's about a 7 HD increase. Now, assuming we can translate that to any other monsters is a dangerous game in 5e because often it just isn't true. In this case, because the two monsters work decently well as comparisons, and because an elephant fiend feels like it should be pretty burly, I am boosting the maelephant's HD to 15.

Hit Points 127 (15d10+45)

If I were using the elephant as the basis for its AC, I'd assume +3 natural armor (since the Dex 9 elephant has AC 12). However, stronger fiends often have really good natural armor; point-in-case the horned devil has +5 natural armor (inferred from Dex 17 and AC 18). Back in AD&D the horned devil had AC -2 and maelephant AC 0, so I anticipate its natural armor to be less than the horned devil's by 2...which actually does leave me back at a +3 natural armor like the elephant.

AC 13 (natural armor)

Putting it all together (Rough Draft)

[SBLOCK=Monster Maths: Maelephant]
Defensive CR
HP 127, calculated with a *1.25 modifier for damage resistances for an expected CR 11-16. That's 159 effective HP. CR 6. Should expect AC 15.

The maelephant has AC 13, but it also has four proficient saves, boosting its effective AC to 15. So it's good.

CR 6.

Offensive CR
This one is going to be tricky to calculate, but I'm just going to go with the most extreme assumption – the maelephant casts blade barrier each round of combat, utilizing it to catch the largest number of targets possible. Again going by "Targets in Area of Effect" (DMG 249), I divide the 100 foot wall of the blade barrier by 30 to get 3 targets. Is a DM actually likely to use the maelephant this way? Probably not, but it does drive home how dangerous the monster can be in ways that are harder to account for the monster math.

3 * (6d10) = 3 * (33) = 99

99 DPR is CR 16, but save DC 16 bumps that down one to CR 15.

CR 15.

Total CR

(6 + 15) / 2 = 10.5

Now, I'm uncertain whether to round up or down. I'm leaning toward up because... First, I assumed a lower damage resistance multiplier (since I was anticipating CR 11-16). Second, I still think that its breath weapon is super nasty. But still, I'm uncertain.

In a case like this, where a monster is on the border line between two CRs and it's not clear to you which way it should go, I suggest trying a different effective HP multiplier for damage resistances. So, let's say I assume it's meant to be a CR 5-10, that means I multiple it's HP by 1.5.....which is 190 HP.

That will give me a Defensive CR of 8!

Working the math that way, the maelephant's total CR would be (8 + 15) / 2 = 11.5 !

So, in this case, my intuition to bump its CR up to 11 is right.

The maelephant is CR 11.[/SBLOCK]

[SECTION]Resources: Monster Conversion
Official WotC Conversion Guide
Brent Newhall's 1e-3e-5e Converter
Pathfinder to 5e Converter by [MENTION=6670944]Kryx[/MENTION]/Mark Lenser
Equating AD&D 2e XP to 5th edition CR (my thread on ENWorld)[/SECTION]