Baldur’s Gate: Descent Into Avernus: 10 Things you need to know before you run it

Baldur’s Gate: Descent Into Avernus is a spectacular, fascinating trip into a less explored avenue of the multiverse and I can’t recommend it enough. However, when you love something (and have run it for over a year), you know exactly where its strengths and weaknesses are. Here are the 10 Things you need to know before you run Descent Into Avernus.

Spoiler Warning!

This is a guide for Dungeon Masters considering buying Descent Into Avernus, as such, it contains major spoilers. If you are considering being a player in this campaign, you need to look away NOW.

1 – Chapter 1 is stupid hard

Have you ever heard of Death House? It’s the opening for Curse of Strahd that helps players level up from 1 to 3 and it’s known for turning player characters into bloody corpses. It has NOTHING on the opening to Avernus. Baldur’s Gate is known as the City of Blood and it lives up to its name immediately.

After the player characters are conscripted by Captain Zodge, he sends them on their way to meet with a spy to find out more about a cult terrorizing Baldur’s Gate. If the party doesn’t obey within 48 hours, Zodge just sends 6 Veterans and a Flameskull after a level 1 party to drag them to the plot. In addition to being massive overkill, it begs the question: why isn’t he sending this gaggle of soldiers to talk to the spy? It’s intended as a deterrent for “that guy” players, but it still feels so absurdly harsh.

At some point, the PCs arrive at Elfsong Tavern where they do a lot of world-building with fleshed-out NPCs to talk to and investigate, but eventually have to talk to the spy Tarina. Midway through their talk with Tarina about the cult, Tarina’s enemies show up in the form of a Bandit Captain and seven Bandits with a score to settle with her. These players are level 1 still. This is their first combat encounter. I’m sure there are power-gamed player characters that could make good tactical decisions, utilize cover, and use spells to turn the tide. For each of those parties, there are twice as many newbie parties who roll bad initiative, don’t know their spells well enough to help, and get slaughtered an hour into their first Avernus game. Yikes.

Worse than that, when they manage to get information about the cult out of Tarina one way or another, they go to the Dungeon of the Dead Three at level 2 and have to fight some of the most brutal uphill battles I’ve ever seen. Not just that, it’s long. Look at this thing!

The Cult of the Dead Three has some insane abilities from giving players vulnerability to piercing, Fireball, Spiritual Guardians, canceling damage on a reaction, and all sorts of resistances to magical effects. While the players don’t fight a lot of them at once, there are so many encounters, they are bound to start running out of cards to play by the end of the dungeon where they meet a Death’s Head of Bhaal which is just a cluster of painful features. I generally think it’s DM malpractice to cast Fireball against a party that may not have enough health to survive even one. *Fireball’s average damage of 28 against a party whose average health is somewhere between 20-32 apiece seems to me like a boss monster, not some guy they may or may not run into in the middle of the dungeon.

*(PS: the Master of Souls that casts this can convert any of its spell damage to necrotic damage, so your Tiefling players should still be afraid.)

With a few exceptions, the module is never this hard again. Given the nature of Avernus tilts towards a railroad fetch quest, it would help the party to take some time between each of the Dungeons in this first chapter and let the players actually experience the absolutely huge and detailed Baldur’s Gate documented in the back of the book (pg.158-200). They can’t leave since the city is locked up due to the refugee crisis (pg.12). Leveling them up one to two levels higher than the book recommends until chapter 2 will also increase their odds of survival. It delays your player’s jump into Avernus proper, but it will do a lot to establish their relationship with the material world they are fighting to protect and can give them time to bond as a party before they are tested by fire. This is also a time for them to pick up on misconceptions average folk might imagine about the Nine Hells and naturally learn about the religious forces they will have to face.

However, if none of this sounds like your party’s cup of tea and they just want to get to the devil punching, you should probably reimagine the opening entirely and start at chapter 2 pg. 52.

2- The fate of Lulu and Gargauth (the Shield of the Hidden Lord)

Among the things that Avernus does to provide a lot of player freedom and DM interpretation, they kind of just throw Lulu and Gargauth at you and just expect you to figure them out without much guidance. Managing these two will help define your Avernus Adventure so let’s deep dive into these two for a minute.

I bring them up together because they represent the Angel and Devil on the player’s shoulders, the best and worst the players can be. I’d encourage you to use them as framing for the game, but also give them both character arcs and growth as the story progresses. They should encounter challenges and have to react to them. The game has a vague endpoint for them both, Lulu wants to save Zariel and Gargauth wants to be free, but I would say those should evolve as the story progresses. I hope you take my advice on their character to help inform their journeys.


Let’s start with Lulu (pg.51). She is a dog-sized floating green elephant given to the party when they leave for Avernus from Candlekeep. In terms of characterization, Lulu is good-natured, kind, forgiving, and a bit ditzy but part of that is the amnesia she experiences as the former mount to Zariel banished to the material plane. She is a powerful Celestial known as a Hollyphant and most of her powers are locked behind her erased memories. She is fully aware of the fact memories are missing, but that doesn’t stop her from trying. That’s a good amount to work with when juxtaposed against the horrible circumstances she can be in. How she reacts to Avernus will be important. Does her demeanor change when she’s up against the Devils that ruined Zariel? Is she a bit forceful with the players if they want to kill Zariel? Lulu is more than a pet, she’s a fully thinking character and her behavior should reflect that. Even people that are happy all the time have flashes of other emotions under extreme pressures. 

For the story to work, Lulu has to survive to see Mad Maggie on the floor of Avernus for a dream sequence to tell the players where to go, and then she can die because she just comes back to life when the players arrive at the Bleeding Citadel to claim the Sword of Zariel (pg.139). All that being said, as a DM, I tried to keep her alive as much as I could because resurrecting her later seemed so weird. I would advise making her cautious around combat and build a relationship between her and at least one of the party members so there’s an organic reason she sticks around constantly. She’s certainly a great boon to the party with the incredible abilities of a Hollyphant, but likability beats utility sometimes. 

On that note as well, her abilities need to start coming back really fast. I actually disagree with the book that just broadly says she gets her abilities back at chapter markers (pg.51). The small stuff like Protection from Evil and Good should come back on the third or fourth fight the party gets into in Avernus. The best way I can think to illustrate her growth would be that she needs to level up roughly when the party does. Since Avernus recommends she unlocks abilities based on memories (which the book supplies, abridged below) and experiences, here’s the timeline I used. 

Player’s Timeline Lulu has/gains… Memory Gained
Meeting Lulu The Light Cantrip and spell invulnerability field “The Zariel I know is gone…”
Leaving Eltruel Her x2 a day spells “The Demon Lord Yeenoghu hates the sword…”
Meeting Mad Maggie Banishment (might help with the Madcaps) “Yael took the sword and plunged it into a rock…”
Players reach level 9 Shapechange (if this is too early, she seems more powerful than the party) “I used to be Zariel’s war mount…”
Clashing with one of Zariel’s Lieutenants Heal “I wandered Avernus for a while…Maybe Mahadi can help us!”
Finding the Location of the Bleeding Citadel Teleport “It was Zariel who sent me back to the Material Plane… maybe there is hope!”


Gargauth the Pit Fiend is, well, a lot. The players find him trapped in the Shield of the Hidden Lord when they find Tharivus Krieg in a vault. The shield looks like death’s melted face, it telepathically communicates with players in a pack-a-day smoker’s voice, and it tries to incite violence and damnation with every suggestion. However, Gargauth insists that he is a celestial that needs to be freed from the shield by angels in hell. I’m not making any of that up. That’s what it says on his introduction page (pg.42) and his magic item page (pg.225). 

His lie is so obviously contradicted by everything around him you basically have to play him self-aware and charismatic. It makes the players feel like they are missing something. “I know how bad things look, but appearances can be deceiving and I promise you that’s the case right now, I want to help you,” is the kind of dialog I employed with him. He has to find a way to disarm their expectation that he’s evil because the book is super obvious about it

The Shield itself is a +2 legendary item with charges for Fireball and Wall of Fire with an insane saving throw as well as an emergency fear aura that Gargauth controls, not the player. That is so much power for the player to receive at level 4 or 5, Gargauth probably shouldn’t put all his cards on the table immediately. He’ll probably tout his increased defense bonus but only talk about the fire charges if the players need convincing or are having second thoughts later. The fear aura is self-defense. If the party member wielding him is in danger of dying, this is when Gargauth deploys the aura. It isn’t out of altruism. It’s about him keeping his courier alive. When questioned about why he didn’t bring it up before he lies (which he should be able to roll high on deception thanks to his high charisma) that he didn’t know about it until that very moment. He’ll have to straddle a line between being earnestly helpful to prove his worthiness to stay with the party, while also withholding any information he can that might damage his case

The reason he wants to go with them so bad in the first place is that Gargauth thinks that going to hell will restore enough of his strength that he can break out. He is wrong. In reality, the options to get Gargauth out are slim. Dispel Evil and Good have a 1% chance of working unless cast by a solar, planetar, or archdevil. A god can pull him out by just saying his name and touching the shield. 

I’d expand this to include other powerful entities such as an Emperyan which the players can meet if they investigate Uldraak’s Grave or possibly Mordenkainen himself which they can also meet at the Tower of Urm. The reason I recommend this is because the story is far more interesting if he does get out. The party’s relationship with him can make him an interesting final boss, an informant who rats on them to Zariel in exchange for more power, or maybe an ally that they know is evil but have a non-aggression agreement with and they have to avoid each other because hell will force them to fight otherwise. Time muddies a lot of things and when the players have a relationship with the NPC before they ever have to even consider coming to blows with them it adds so much more weight. Doing something with Gargauth will always be more interesting than just having him be a mute magic item. 

(PS: Gargauth is actually a character from the early lore of D&D. While I never want things like that to be forced on any DM is it cool information to have if you want to lean traditionalist or just use it to inform his character.)

3 – Saving Eltruel is at the core of the story

I’m not even enough of a lore nerd to know how important Eltruel really is. The fact that the capital of Eltrugard just sinks into hell despite famously being the Holy City should be nothing short of traumatic to citizens of Eltrugard. This is apocalyptically bad. Even citizens of Baldur’s Gate, who have a complicated relationship with Eltruel, need to have a pretty serious gut reaction. It shouldn’t be hard to hear people freaking out in the streets wondering “are we next? If they aren’t above reproach, what’s going to happen to us? Why have the gods abandoned us? Is this the end?” The driving emotional core for the story is saving these people. It can’t JUST be a faceless random city.

More than that, I’d make it clear that it’s not just the city that’s in hell, but also that Tharivus Krieg had all the citizens of Eltruel pledge their souls to him in the equivalent of the Pledge of Allegiance and he pledged those souls to Zariel. The citizens of Eltruel aren’t just in immediate danger, they are in ETERNAL danger. All their faiths and love of their gods may not mean anything because of a TECHNICALITY. I don’t feel like I need to be in-depth about the kind of visceral outrage this sparks in players once they figure it out.

The Sword of Zariel is the one thing the party learns about that can free the city from the chains dragging it to hell. That’s why the sword matters. The emotional weight keeps this story from just being a fetch quest.

I’d recommend giving each party member an NPC ally in Eltruel that they can save and interact with. Friends, family, old co-workers, ex-wives, something to really sell home how bad things are. If the party has even one strong connection in Eltruel who is in deep trouble, that’s enough to hinge an entire campaign on.

I did have one player say he was from Eltruel originally before coming to Baldur’s Gate. I cautioned him in advance that being from Eltruel carried a lot of baggage I couldn’t share yet, but he said that’s the story he wanted to tell. The look of shock and horror when it was revealed how bad things were for him is something that will always stick with me. I’m not sure it’s right for every table and every party member, but having even one player character from Eltruel brings yet another layer of drama to the campaign.

4 – Chapter 3 is a LONG Railroad (pg.74-133)

When people talk about Descent Into Avernus, this is almost always what people imagine. Memories are made here in a strange, horrible land filled with tricks, wonder, diabolical plots, and terrible con artists all struggling to survive.

Chapter 3 is 59 pages, but this length is deceiving. There are two paths put here based on where the players go after they rescue Lulu from a Hellwasp nest: the Path of Devils and the Path of Demons. Broadly speaking, it simply determines which kind of enemies you will be facing most often and which evil fiend NPCs the party must bargain with. Either way, puritanical clerics and paladins are going to struggle. This is also, unfortunately, where the campaign is at its most railroad and fetch quest-esque. There is a LOT of running around trying to find the MacGuffin for whichever NPC promised them the next clue as they frantically search for the Sword of Zariel which the entire campaign relies on. It’s a bunch of fetch quests to further another fetch quest.

It is fantastic for players who see the campaign as a sort of roller coast with incredible highs and insane drops who simply enjoy the journey for what it is. It features incredible sets, encounters, meetings with legendary D&D figures

For players who care a lot about making choices that matter or making their own path, this can be agonizing. It can feel like it requires so much to move the needle of progress that it’s not worth it and discourage those players. For them or for DMs who like to emphasize player choice above all else, I hardily recommend Eventyr’s Avernus as a Sandbox that restructures the campaign around a free form chapter 3 with fewer steps but far more choices and the opportunity for the players to see everything chapter 3 has to offer without playing it twice. It is extra work for the DM in terms of reading and adapting, but my players had a great time with it and I found it so freeing.

5 – Zariel needs to impact the story before she appears

Zariel is a larger-than-life character. She’s not just a person, but an archangel that fills a lot of roles. She’s a part celebrity, part legend, part general, part nun (kinda?), and part ruler. My point being, your players should know who she is before they ever actually meet her otherwise she’s some distant dark lord that the players may know nothing about. News about her would get around. Whispers about her in the Wandering Emporium should be audible. The fanatical loyalty she inspires in enemy NPCs should be a distinct character trait. Her values should be evident based on the kind of people she promotes and empowers. Tieflings of Zariel are in Mordekainen’s Tome of Foes and maybe a good place to start to inform this.

However, her actions should have an impact on the campaign. Her reactions to either the player’s actions or the actions of other Avernian residents like Bel or Mahadi will tell the party everything they need to know. Bel is a possible party ally, transactionally only though since he’s a DEVIL, that the players can make against Zariel. She’s in his position and he wants it back so he’s motivated to act against her. However, if one of the players gets too chatty with an enemy NPC who tells Zariel that Bel is rebelling against her, how does she deal with that? Does she take it as permission to kill this thorn in her side? Is he more valuable alive so she simply strips him of his resources until he relents and cuts a deal with her for more loyalty? Does she contemplate how to use this information against him and set him up for failure as grounds to demote him to an Imp? Whatever she decides, her Intelligence, Wisdom, and Charisma are all over 25 so she’s more than skilled enough politically and tactically to shut down disorder in her ranks.

When the villains react to things the players do or choices they make, the world feels more alive and also services the plot by providing exposition to the players about the characters they can’t meet yet. Both player and non-player characters will be defined in an Avernus campaign by their relationship to Zariel. She should mean something to each of them, and there can be wild disparities in their relationships based on how they interacted with her. Zariel could have saved an Elf PCs hometown 200 years ago, but another PC just watched their hometown of Eltruel get dragged to hell and they are furious.

6 – Bargain Bin Death Saving Throws (pg. 78)

The idea is simple for this one: when a player character is rolling death saves, an archdevil may telepathically contact them with an offer to restore them to 1 hit point if the player character is willing to perform a dark deed. The archdevil refuses to explain the deed, but this is not a soul sale and I’d let the player know that. This will be specific and to the benefit of the archdevil. Upon accepting, the player is under the effect of the Geas spell with no saving throw.

This is an optional rule, so it is not inherent to every game of Avernus, but I feel it’s important to provide because of what it does for the narrative. Two of the biggest themes in Avernus are temptation and redemption. Having the full Avernus experience means the temptation must be present. Not every player character will be willing to sell their soul (HOWEVER, the book does include a table of things they may get if they decide to sell! Pg. 213-215), but many player characters are willing to compromise a single action for survival. This is a must if the entire party is some variation of lawful or good. Also good to consider is bargaining with monsters from Tasha’s Cauldron of Everything (pg.148-149) for additional ideas for what a Fiend wants.

This may be a way to introduce Zariel early, whether or not she knows why the party is in Avernus up unto that point. Alternatively, it’s a way that Bel or other figures like Titivilus or Moloch (both from Mordenkainen’s Tome of Foes) can introduce themselves to the main story. Political intrigue is less a part of Avernus, but a definite part of the Nine Hells.

If the party splits, then one of them bumbles into combat and goes down, this is a good way to save them without being TOO merciful. They are in Avernus. Medics and kindly strangers aren’t coming to save anyone.

7 – Demon Ichor mutations (pg. 78)

Demon Ichor is some of the nastiest stuff in Avernus, combining all the swinging power of a Sorcerer’s Wild Magic with all the personal vindictiveness of the Deck of Many things. The mutations are called Flesh Warping. These can grant superhuman powers, wreck a character’s ability to fight, or sometimes just mutate them beyond recognition. Just look at some of these things!

Paladins, Fighters, Barbarian’s, and anything else that has a solid Constitution saving throw has less to be afraid of (DC 10 isn’t that hard), but the results of the Ichor are worth exploring. Many, many people in Avernus have come into contact with Demon Ichor and as a DM you should show what happens when exposed to it before your players ever have to risk being mutated. Some of the Warlords (pg.90) have foot soldiers that can wield weapons covered in the stuff that disperses with a single hit and the module also puts some of the stuff directly in the player’s path. Greater Restoration can also cure these effects, but for players that takes a long time to level up to. These mutations are going to be character-defining unless you build in a mechanic to get rid of it faster.

Some of the strongest storytelling can be found here. At my table, I had a Chaotic Neutral Lizardfolk who chugged Ichor every chance they got because that was part of the fun for the player and the character who was constantly striving to become the ultimate life form. As part of the same table, I had players who were terrified of it. When one of those players who lived in fear of it was knocked unconscious and into a pool of the stuff, another player character grimaced, took one last look into a mirror knowing it might be the last time he ever looks normal, and jumped in headfirst to save his best friend from further disfigurement. It’s moments like that where I realized the storytelling potential of Avernus. You are able to see the best and worst in player characters as they constantly grapple with a world designed for maximum cruelty.

8 – Make Time for the War Machines (and travel in general) Pg. 216-222

Where else are players going to fulfill their Mad Max fantasies if not here?

The Infernal War Machines are super cool! There are four vehicles to choose from with their own custom stat blocks, special combat positions, fueling requirements, repair rules, mishaps, exhaustion, weapons, and all sorts of other goodies. If that sounds like a lot, it’s more intuitive once you sit down to read the rules. It’s something unique to Avernus that, as of the writing of this article, there isn’t another natural place it fits into D&D 5e. They even give you specific enemies to go against with the Warlords of Avernus (pg. 90-91). The encounters are a bit tough, so play at your discretion, but they are a great way to bridge getting from one place to another.

This is an area I dropped the ball for my players in terms of story and it’s something I definitely regret. It’s another moving piece the game players can get creative with, especially with their spells or if you have a Barbarian jumping from car to car fighting everyone, using the spell command on the driver of another vehicle, etc. Traveling in Avernus is brutal by foot (pg. 79) and the fact that the designers of the module had the forethought to design an interesting and unique way to keep things fresh is a testament to their good planning.

While the War Machines change the math a little, don’t forget the basic travel rules of D&D (I do all the time, that’s why I bring it up) in the Player’s Handbook (181-182) and DMG. (108-112)

9 – You need to think about what Zariel, Bel, Olanthius, Haruman, and Mahadi are doing

This might seem strange, but the adventure requires them to be doing other things away from the party for the story to progress. Haruman, for example, just attacks the party when they free Jander Sunstar from Haruman’s Hill (pg.93). What was he doing until then? How did he get there so fast? If he was in the area, should he have stopped them on their way in? He’s a second in command to Zariel, shouldn’t he have troops with him? Should he signal Zariel that something is wrong? Nope! He just charges in, lance down on Nightmare back, and tries to take on the randos messing around his stomping ground completely solo. 

Now, this is not a plot hole. I’m a big fan of the phrase “it’s only a plot hole if you make it one.” My argument here is that the book sets up a scenario and places the explanation on the DM’s shoulders. This is not the only time this happens. Olanthius has all of his journals and his own personal hideout at the Crypt of the Hellriders and he’s not there when the players arrive at the Crypt. The module even says he can be summoned from any place in Avernus to fulfill his duty to protect the site (pg.103), but he arrives by carriage and he returns if the players desecrate (read touch or examine too thoroughly) anything in the crypt, possibly taking an hour so the players have time to read his journals and figure out he’s sympathetic to their side.

What was he doing? He’s military, shouldn’t he be fighting on the front lines? Does he come back with some of his spells and health drained from fighting demons? If he’s full, was he at a board room meeting? Was he watching another site that the players could find if they don’t fight him at the crypt? It doesn’t matter if the players know or not, but it matters that you know so you can handle any questions or potential follow-ups should things not go according to the book.

A lot of these characters (Zariel included) are just “off doing something” somewhere else in the world. I understand the book only has so much space on each page and doesn’t want to bother the DM with even MORE reading, so this isn’t a fault. However, it is something to prepare for. It’s probably a good idea to have a basic daily routine planned for some of these characters so you can adapt more organically rather than just stare at the book confused if something goes wrong. If the world follows its own internal logic, that’s really all that matters.

10 – Claiming the Sword is simple once you get there, don’t let that limit you

“Who gets the sword” is a question your players may be asking themselves throughout the game.

Plain and simple, the question is answered on pg. 145 “any character who survived Lulu’s memory can pull the Sword of Zariel.” The memory referred to is a gauntlet through an animated dream of Lulu’s that Yael puts the characters through once they arrive at the Bleeding Citadel where the Sword of Zariel is. It also makes mention of an “if the sword deems them worthy” requirement. This is only sort of true. The reality of the sword is that it irrevocably alters the wielder to become worthy (pg. 226-227). It alters them so fundamentally, the wielder arguably qualifies as an Aasimaar per Volo’s and gains new (or replacement) Personality Traits, Ideals, Bonds, Flaws, and alignment (Lawful Good).

What I did, and would recommend is, having Yael’s ghost suggest a wielder but allow the players to decide amongst themselves who takes the blade. There are rollable tables for the personality traits on the Sword’s item page, but I’d roll these in advance and use them as a template for who Yael recommends take the blade as informed by Lulu’s memories. The more similar a character is to the rolled traits, the more likely Yael is to recommend them.

Beyond that, the wielder of the sword basically decides which end they go after as described in chapter 5. They have the keys to the campaign now. If they try to rebel and become the new Lord of the First, they can. If they want to kill Zariel, they can. If they want to try to cut a deal, they can. The choice of wielder matters that much. Make sure your players feel that.

…and a few more things that might help you out!

Use the concept art in the back

There’s actual concept art that isn’t used in the book for Reyha Mantlemorn, Sylvira, Falaster Fisk, new Merronoloths, Mahadi, and a few others like a sizing chart for Zariel’s Airship. It’ll save you some time describing everything.

Demons and Devils are VERY different

They are both big monsters, but they should never feel the same. In the simplest possible terms, Demons are twisted animals and Devils are regimented military members. Both get more powerful the higher in rank, but the Demons don’t really have to obey so much as follow the top dog. Devils should give begrudging obedience to the letter of the law, but not the spirit. If Devils can worm out of doing work, they will. 

To actually learn how to play them as vile and competent enemies, I suggest the extensive guides written by Keith Amann on or with his book of the same name. His guides to lesser demons and devils are free and a good place to start.

There are a zillion additional fan resources

To name a few: Helltruel, A Cold Day in Hell, Eltruel has fallen, Abyssal Incursion, Encounters in Avernus, and gobs upon gobs others. They are generally cheaper than $5 or free, come with detailed instructions, maps, and additional content if your players just can’t get enough Avernus.

Until next time,

May your game, have advantage my friends!

-Halfling Hannah

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