Looking to Run Descent into Avernus, Want to Know Any Major Problems With the Module

[Techcaliber]

Hello everyone!

As the title says, I plan on running DIA, and In trying to make sure I know any major problems so I can account for them. Now, I know about aims if the issues with the Baldur’s Gate Portion (plot hooks being weak, death trap fights, etc), and i have a plan for those, so I’m wondering what problems are in the module once you get past the Baldur’s Gate portion of the game.

Thanks in advance!

[micahaphone]

You already know that the initial material plane stuff is a bit railroady, hamfisted, and with questionable balancing to at least one dungeon. I hear the Avernus part can be a great sandbox, I've heard good things about leaning into the infernal war machines.

Minor spoilers for the Avernus portion, Just learned from a few reviews

I hear there's a lost celestial tiny elephant Lulu that acts as the players guide / moral compass that some players hate and find incredibly annoying. Perhaps change that character's personality or motivations. I find it to be a curious opposite of Stool from Out of the Abyss, who everyone agrees is the best.

[Eldariel]

The worst part of DiA is definitely the material plane part. Rewrite it entirely. It's totally tangential and largely worthless (well, there are some important items there but you can deploy those in auxiliary ways). Hell, just start e.g. in Candlekeep with the party ready to enter Avernus if you feel up to it: explain some random nonsense so that they get the general gist of it, and go from there. Avernus itself is cool, if a bit on the easy side. I like using devil and demon statblocks from 3e so they're more magical: makes the encounters more interesting. It's largely solid though, the feel of the place is right and there are various sorts of cool things to encounter.

[Avonar]

Having run this, there are a few issues that stand out.

The Start

The stuff in Balder's Gate is...rough. It's an alright little story but it does very little to get the party invensted in the main plot to come, to the point that I had to come up with something to get them to actually go to hell. Because despite Balder's Gate being in the title, the story is not really about Balder's Gate, it's about Elturel.

My advice is to have the characters start there. Maybe start them at level 3, do a couple of levels of quests round Elturel, maybe have them find that something is wrong, then when the big event happens and Elturel is pulled into hell, they can witness it first hand. It's their home, they now have an attachment to it and want to save it.


Lulu

Lulu is an NPC that the party joins up with to help their journey. And by help their journey, I mean arbitrarily tell them where the next goal is as she just happens to remember more things. This really kinda sucks as a way to get the party to go from place to place, my players quickly found themselves getting tired of following Lulu's directions, only to find it's the wrong place.

The whole thing is written out as a giant fetch quest which isn't good.

Maybe here you can change it to instead of randomly following Lulu around, the party finds that they need to garner the help of one of the extremely powerful figures in Avernus. This could be Tiamat, Bel or even Zariel herself. Have them do the quests with that goal in mind. You can lead them to the same places but it now feels like it's something the players have decided on rather than the NPC dictating everything. Feel free to have them come across Lulu, she's a useful character for filling in the backstory of how this all happened, but don't let her drive the entire plot. If you want to introduce here, there's a perfect place to add her: The Demon Zapper. Take out the unicorn that's there and put Lulu in instead.


Other Bits

Figure out how likely your party is to want to make deals with the devils. If the players are all in on it purely for the novelty, then maybe limit them, only introduce a few big ones with serious consequences. If the players are reluctant to make any deals, throw more at them. Try and tempt them.

There's also an aspect of Avernus that says after each long rest you need to make a save or your character becomes evil. I really hate this. Turn the characters evil through their actions, not by failing a save. Avernus sucks, real bad, and there are many chances to try and bring out the worst in the characters in the name of success and survival.

[Marcloure]

While I did not play the game, I watched Roll20 Presents going through 60-70% of the module. I noticed some things from watching it:


1. The adventure offers no hook or reason for the players to care about the main mystery. There is literally a part on the book where it suggests you to overload a scene with enemies to "encourage" the players to accept an offer. Try to find a tie-in for the Player Characters, maybe involving more of their Dark Secret.

2. I felt that the adventures on Hell was weirdly structured. If the players aren't very curious to just wander on Avernus, the adventure is basically:

• Lulu tells you to go somewhere, so you go there
• someone there asks you to go to another place and do them a favor
• you go to this place and solve their situation
• you return to the person only for them to tell you they know little of Lulu
• repeat
I did not like that structure. You are always walking blindly in circles, doing favors to be rewarded almost nothing. I don't know how to solve this, but maybe you could throw some rumors for the players to catch and be curious about the places around Avernus.

3. Sadly, I can't say much about the ending of the adventure. I know there are some pretty powerful baddies there, but the players aren't meant to fight them, I think. They do have statistics though.

[Schlendrian]

You already know that the initial material plane stuff is a bit railroady, hamfisted, and with questionable balancing to at least one dungeon. I hear the Avernus part can be a great sandbox, I've heard good things about leaning into the infernal war machines.


I have not yet run it (will start my players roughly in the hell part with a selfmade intro from the end of Lost Mine), so take what i say with a grain of salt, but to me it feels very non-sandboxy. the players can walk down one very linear and railroady path or a different very linear and railroady path.
what turned me off most by reading was the amount of NPCs sending them to the next location and then some. there is no real possibility to change the order since every NPC only sends the players to the next in line.

@OP: While it is not complete yet the Remix of the alexandrian gave me lots of ideas of what and how to change. Link here: ...

Here is something that i definitely want to mine for my campaign as well to make it more open and less linear: ...

edit before post: apparently i am not able to post links, so yeah. googling "Alexandrian remix avernus" for the first and "Resources for Avernus Point Crawl/Sandbox reddit" for the second one should be okay

[Unoriginal]

I don't have the time to make a detailed list right now, so I'll just say one thing:


Some DMs like to portray Lulu the Holyphant as annoying, ranging from making her an holier-than-thou jerk to making her stupid and unaware of her own weakness. It is very much *not* how the module presents her, as in it she's truly and sincerely kind and benevolent, and decently wise, smart and charismatic (not to mention an experienced war veteran).

I suppose some people just want good people to be as unappealing as bad people.

[Marcloure]

Some DMs like to portray Lulu the Holyphant as annoying, ranging from making her an holier-than-thou jerk to making her stupid and unaware of her own weakness. It is very much *not* how the module presents her.

The book doesn't present her that way. On "Roleplaying Lulu", the book uses a very childish language to describe her personality:

"Lulu doesn't have a mean bone in her little body. She believes in the power of friendship and looks forward to kicking evil's butt with the characters by her side."

The way she speaks also portraits a somewhat childish, though intelligent, character:

"Someone helped me hide the sword, but I don't remember who. We found a place to hide it, but I don't remember where. I escaped Avernus, but I don't remember how. Most of my memory is gone, and I don't remember why."

[Citadel97501]

Really the biggest issue I have with the module itself is that Lulu is badly written mechanically, her magic neutralization aura is extremely frustrating for many ST's as it randomly ends up being forgotten or would completely shutdown an entire encounter but not in a fun way. In addition as has been said the ham-fisted nature of the module sending you to hell was quite irritating.

[MrStabby]

I would also highlight that certain character concepts can be nearly unplayable, at least when you get to Avernus. This isn't a problem, depending on which caracters people want to play but it is something that your players should be aware of. Your red dragon scorcerer or enchanter wizard might not be doing what they thought they would be doing at character creation. Just makre sure your players know that some classes won't be as fun in a session zero and you should be fine.

[Zeb_by_Proxy]

Running it now. A few perspectives:

- Lulu will depend on your table. While a group of players hunting for a gritty "hellish" experience may find the contrast between Avernus and Lulu jarring, a more good-aligned party or players looking for a "lighter" game may very much appreciate her as an NPC. My players absolutely ADORE her, and have been making online Lulu purchases (stuffies) to wave around during the game and making bold threats to me like "if Lulu dies we riot" etc.

- for the Baldur's Gate portion I leaned heavily into the Volo written chapter later in the book, and treated BG more like a sandbox than the rail-roady plot laid out in the chapter. I found BG VERY rich with opportunity for character development and there are a number of fun parallels that can be developed with the chaos of BG (all those cultists running around) and the forces that Zariel is seeking to defeat in the Blood War. It can make Zariel seem a bit more sympathetic depending on what choices the players make in BG.

- STRONGLY AGREE that the primary problem with the module as written is the lack of motivation for the characters to engage in the first place, and why they should care about the fate of Elturel. Agree with the suggestions to start the characters in Elturel "before the fall". I did this at my table, and had each of the players linked in some way to one of the leaders of the City, or Ulder Ravengard, so that they had a small "we're worried about cult activity in a forest outside the town, go investigate" quest that hooked into the Cult of the Dead Three. A red herring, but really amped up the player care factor for the Cult of the D3 in BG once the players got there. I also had the players role play leading a group of refugees from Elturel to Baldur's Gate, which got them very engaged in the overall fate of the city.

I quite like this campaign, lots of good material here, but really landing the hook in Session Zero and Session One is pretty key to making it work.

[Unoriginal]

Having the PCs work for Duke Ravenguard as he travel to Elturel, and them not entering the city for X reason leading to them witnessing Elturel's Descent could be a good plot hook, yeah.

"Just before getting into Elturel, the Duke has an urgent letter for Captain Zodge and trusts the adventurers to deliver it", then one hour on the road to Baldur's Gate the PCs hear Hell breaking loose and turn back to see what happens to Elturel would both justify why they're interested in the mystery and why the Flaming Fist Captain want those PCs in particular to help out.

[5eNeedsDarksun]

So if you are sorted for a Chapter 1 fix that's great. Chapter 2 is fairly reasonable to run as is.
The big issue is Chapter 3. I'd call it a good skeleton for an adventure. There are some interesting NPCs, good encounters, great art, and neat ideas around ideas like Soul Coins and Infernal War Machines. However, I'm spending a lot of time fleshing this thing out and providing enough detail both for interesting storyline(s) and enough XP to legitimately level up. There are encounters that don't have maps. There's not really an 'economy' in the sense of how gold, ichor, and soul coins could be traded, though you will get a rough guide from a shop or 2 in the Wandering Emporium. There is a short list of Warlords, but you really need to figure out how you are going to include them for good effect. Basically expect to work ahead for most/ all sessions.
Mechanically the War Machines are tough in combat as they have few HP and move way faster than everyone else, so you might want to adjust this before you include them.
I'd strongly suggest getting a copy of Encounters in Avernus supplement which has helped me a lot. It also includes a bit of stuff for chapter 2 if you find you need it.

I really like this adventure and my players are liking it... but I have a lot of time to devote to this at the moment. It's unfortunate the creators donated so much space in the book to things in BG that just don't help the adventure and shorted what should be the meat of the thing. I'd never recommend this to a starting DM or someone who is limited on time.

[Mr. Wonderful]

I ran the opening chapter twice due to interruption by the pandemic. Unsurprisingly, the second run was a lot better.

On my first go through I played it straight and wasn't too fond of the linear plot line, and the opening dungeon is pretty brutal - killing two characters permanently which isn't easy to do.

Starting over using Fantasy Grounds I invested some small additional dollars on the "City Encounters" pack from DM's Guild, which was well worth it. This was my first time DMing using Fantasy Grounds and so I incorporated one of the encounters into each one of the character's session zero. That really helped me get accustomed to the basics of the software while in a simple environment (a single 1st level character).

The encounters also do a great job of illustrating the stress that the fall of Eltural has placed on Baldur's Gate and the whole Sword Coast. The extra action gave me a reason to pump up the characters an extra level, which helped calm the extremely tough early encounters down to challenging ones. I had the characters pay it back later by skipping one of their later milestones.

I wasn't particularly impressed with the way the NPCs were written, so I changed them wholesale, making Sylvira more formidable, Trax a grump, got rid of Reyna altogether and took the spotlight off Lulu. I seriously enjoyed roleplaying the Shield - though the party is a bunch of do-gooders and weren't willing to listen to it's eminently reasonable offers.

The module seems to really hit its stride once the Descent happens, so hopefully this helps!

[Wraith]

I would add my voice to the choir who have mentioned that the Material Plane stuff is quite weak. Specifically, in my own preference, it's got a number of important plot-points listed and then a whole bunch of empty "the players should side-quest until they level up" filling in the space.

For example, at one point the party has to infiltrate a Villa to chase a villain - the Villa consist of 50-60 rooms or so, and only about 5 of them have anything of interest or note besides knick-knacks that can later be sold for money. Unless your party particularly enjoy the "Is the door locked? You can't tell. I try to pick the lock. It's already unlocked. Is the door trapped? Check for traps. I roll a 16. There are no traps" pantomime being repeated dozens of times for a handful of gold coins as reward, you should definitely feel free to abridge the experience and narrate to your party just how big and empty the Villa is rather than spend 2 hours tediously finding out for themselves.

I would also suggest that you feel free to combine several NPCs for the sake of brevity, and because some of them are just "lol random" stupid, as Forgotten Realms tends to be rife with.

As one early example (MINOR SPOILERS): The party travels to Candlekeep in order to find a Wizard who can get them to Avernus. They find a Wizard there named Sylvira who.... can't get you to Avernus because she doesn't know the right spell. So she tells you about another Wizard who can do it, and to get there she summons a handful of griffons for you to ride and they just take you to the guy's doorstep. There's not even any diplomacy or similar rolls needed, she's quite happy to tell you everything you need to know so it just wastes your players' time. There's absolutely no reason for this transaction, or why they need to introduce another Wizard when you're otherwise never going to see either of them again after this event, so why introducing two of them when only one is of any use?

Also the second Wizard - Traxigor - is a talking otter, because of some utterly pointless and non-useful reasons. I hated that guy and the time he wasted so, so much - this is theme that continues throughout DiA (and Forgotten Realms in general) as so many of the NPCs are just there for padding, and have "hilarious" quirky appearances or personalities that, unless your party really likes that sort of thing, can probably be toned down or rewired without problems.

[jaappleton]

I am going to be brutally honest and unfiltered in my response.

Some small spoilers may be included. I’ll try to be intentionally vague.

Ready?

Let’s begin.

DiA is, in my opinion, the absolute worst official 5E module there is. It’s hot garbage that should legitimately not exist. Literally it’s one massive fetch quest that also manages to completely invalidate numerous subclasses and takes agency away from the player.

Issues include:

1. Enemy resistances. Be willing to make deals with various fiends or be out of luck and rendered either only halfway effective in combat, or completely ineffective depending on your subclass. Wanted to play a Fire Dragon Sorc? LOLgoodluck. Storm Sorc? Also a joke. Light Domain Cleric? Pray to Lathander, you’ll need him. Upstanding Rogue who won’t make a deal for a magic weapon? Just start rolling up a new PC now. “Oh well the party can include an Artificer, and some players can be Monks who are innately magical-“ Sure. They can. But to be effectively they HAVE to be that. Again, taking away player agency. It’s poor design is what it is.

2. The fetch quest. My goodness this is a train wreck. Depending on the players choices, and who they want to help, it can literally, without any exaggeration, end up being “Go here and talk to X. Well X can’t help but they send the party to Y. Y isn’t able to help but sends the party to Q. Q isn’t able to assist but sends the party to M. M has no idea but sends the party to Z. Z tells the party to collect F and then sends the party back to X.” WHAT THE HELL IS THAT?! HOW IS THAT FUN DESIGN?!

3. The “Mad Max” aesthetic. This could have been amazingly fun but instead is convoluted and outright poorly implemented. Here’s some death-mobiles but with clunky rules about them to make them not at all fun and just a headache, enjoy dealing with that.

Unless you’re willing and able to very heavily modify the adventure, in absolutely no way can I recommend anyone play this adventure.

It’s not just rough around the edges. It’s outright badly designed. It’s not like Tyranny of Dragons, which was the first 5E adventure so they were still ironing out some issues so you can kind of give it some leeway. There is no excuse for this module to be so poorly designed.

[carrdrivesyou]

Here are my thoughts:
1. Elturel: Getting out of the city is mostly left to the players' imaginations. My group fumbled around for a session and a half looking for a way down.

2. Railroaded: Most of the plot elements can act independently of one another, but they are presented in a very "go here, then there" fashion. Feel free to mix those up. My DM did, and it made a HUGE difference.

3. Hellish Fights: Your PCs are in Hell. The fights are going to hurt. That being said, don't be afraid to crank up the difficulty in some places, or set clever ambushes and strategies.

4. Lulu: Lulu was the single most annoying thing in my playthrough. She starts as being helpful in Elturel, then quickly moves to being an active handicap by mid campaign. The fiends want her dead, and can sense her for miles around. She is a giant "kick me" target with wings and a snobby, immature attitude. There are several ways to replace her, my favorite being the Shield of the Hidden Lord. Lulu is just annoying and breaks the idea of a trip through Hell.

[Unoriginal]

Here are my thoughts:
1. Elturel: Getting out of the city is mostly left to the players' imaginations. My group fumbled around for a session and a half looking for a way down.

2. Railroaded: Most of the plot elements can act independently of one another, but they are presented in a very "go here, then there" fashion. Feel free to mix those up. My DM did, and it made a HUGE difference.

3. Hellish Fights: Your PCs are in Hell. The fights are going to hurt. That being said, don't be afraid to crank up the difficulty in some places, or set clever ambushes and strategies.

4. Lulu: Lulu was the single most annoying thing in my playthrough. She starts as being helpful in Elturel, then quickly moves to being an active handicap by mid campaign. The fiends want her dead, and can sense her for miles around. She is a giant "kick me" target with wings and a snobby, immature attitude. There are several ways to replace her, my favorite being the Shield of the Hidden Lord. Lulu is just annoying and breaks the idea of a trip through Hell.

Lulu having a snobby, immature attitude is an invention from your DM, and so is the "the Fiends want her dead and can sense her for miles".

In the module, Lulu is nice and kind, and *at most* disappointed if the PCs act as badly as the rest of Avernus. The only two times Lulu is singled out as a target is 1) when the PCs are close to the one nest of creatures that specifically want to eat the Celestial (only time in the whole campaign) and 2) a bad guy offers to trade the life of a creature that has one of the good alignments for a relic the PCs need, and it's precised any good individual would do.

Other than that the Fiends don't want to kill Lulu more than they want to kill anyone else.

If anything most Devils would probably prefer enslave her to killing her, if things get violent, 'cause she's pretty valuable to them. Of course the real prize would go to one who could corrupt her, but that's easier said than done.

[Sigreid]

Running it for my group right now. Honestly, if I knew then what I know now I wouldn't run it. I find it boring and tedious. Your results may vary.

[Sandeman]

Our DM was planning on modifying it heavily to make it playable.
But ended up scrapping the whole campaign as the adventure seemed not well suited for our groups playstyle anyway.

[mangosta71]

As a player (my group will finish it this weekend), I really haven't enjoyed the module. It's very much a railroad. You're forced to make deals with either demons or devils; there's no adventure path for a character that refuses to deal with fiends, i.e., most good-aligned characters. There's no real exploration of Avernus; anything but the main objectives is just something you might find randomly along the way or come across while you're lost.

The DM hasn't been forcing the "roll or turn evil" thing every time the party takes a rest, but the constant saves against exhaustion have done more damage to the party than the ****ing devils; we had to houserule that a long rest clears all levels of exhaustion or the entire party would have been dead by the third day (most of us wouldn't have survived the second).

Vehicle combat sounds cool, until you realize that one of the results on the Avernus Chase table is a TPK and there are A LOT of rolls on that table. Then you also discover that Demon Grinders have a wrecking ball that will almost one-shot the party's vehicle.

The "battle" of Idyllglen just made me angry. The party appears so far away from anything else that there's no way to save anyone. We were still more than 300 feet away when the demon broke down the door to the church. The dog and girl were both dead before we got clear of the gnolls. Also, hope everyone in your party is a cleric or druid with all their 5th level slots left and Greater Restoration prepared, because that's the only way to not suffer even more exhaustion when the corrupted guards appear. Speaking of which, if your wizard tosses a Fireball at them, he's dead because you take exhaustion for every single one that you kill. And there's no indication or reason to suspect that that will happen before you take one out.
Infuriating is too mild a word for this bull**** module.

[5eNeedsDarksun]

I would add my voice to the choir who have mentioned that the Material Plane stuff is quite weak. Specifically, in my own preference, it's got a number of important plot-points listed and then a whole bunch of empty "the players should side-quest until they level up" filling in the space.

For example, at one point the party has to infiltrate a Villa to chase a villain - the Villa consist of 50-60 rooms or so, and only about 5 of them have anything of interest or note besides knick-knacks that can later be sold for money. Unless your party particularly enjoy the "Is the door locked? You can't tell. I try to pick the lock. It's already unlocked. Is the door trapped? Check for traps. I roll a 16. There are no traps" pantomime being repeated dozens of times for a handful of gold coins as reward, you should definitely feel free to abridge the experience and narrate to your party just how big and empty the Villa is rather than spend 2 hours tediously finding out for themselves.

I would also suggest that you feel free to combine several NPCs for the sake of brevity, and because some of them are just "lol random" stupid, as Forgotten Realms tends to be rife with.

As one early example (MINOR SPOILERS): The party travels to Candlekeep in order to find a Wizard who can get them to Avernus. They find a Wizard there named Sylvira who.... can't get you to Avernus because she doesn't know the right spell. So she tells you about another Wizard who can do it, and to get there she summons a handful of griffons for you to ride and they just take you to the guy's doorstep. There's not even any diplomacy or similar rolls needed, she's quite happy to tell you everything you need to know so it just wastes your players' time. There's absolutely no reason for this transaction, or why they need to introduce another Wizard when you're otherwise never going to see either of them again after this event, so why introducing two of them when only one is of any use?

Also the second Wizard - Traxigor - is a talking otter, because of some utterly pointless and non-useful reasons. I hated that guy and the time he wasted so, so much - this is theme that continues throughout DiA (and Forgotten Realms in general) as so many of the NPCs are just there for padding, and have "hilarious" quirky appearances or personalities that, unless your party really likes that sort of thing, can probably be toned down or rewired without problems.

You make a good point about the amount of material there to effectively get the characters through levels 2-4. I just don't know why it's all there. It feels like an assignment that was given to a very talented high school student who didn't manage their time well. It's clearly trying to do the job of being a resource for DMs who want to run BG as a homebrew, but at the expense of the later part.
I think they'd have been further ahead to just have the party sucked into Avernus while in Elturel and run levels 1-6 there.
That said I'm still in the camp that likes the thing and after what I thought was not our best session last night (level 8) 2 players contacted me to say they loved it. But it's become my own baby to heavily modify so after hearing from some others I can see if the DM wanted something to play as-is it would be tough.
I think some of the criticism I read on the thread is a bit harsh though, particularly about certain characters being weak or DMs making some NPCs deliberately annoying. Of course certain builds are going to going to be hampered; you are going to Hell. There are ways to even use blasters effectively unless your DM is a total prick and doesn't give you a heads up, as thunder/ lightning works against most devils and is usually only resisted vs Demons. Fireball is generally strong and overused anyway, as are some of the full casters that are hampered, so I think both my players and I are enjoying the change in tactics.

[DonLouigi]

I have played the Campaign as a Player, or rather we are still playing it and are on the brink of the finale (shortly after getting the sword) so I have not read a lot of the thread for fear of spoilers.

I have to add, my GM wanted to have a very low-prep game and pretty much only reads a few pages ahead every evening. This is not the ideal style of play for any game, so take everything I am saying with a grain of salt. There could have been misunderstandings or mistakes by my GM or stuff like that.

I cannot really comment on the BG stuff, as I joined the party later towards the end of that. However, I made a character that was quite invested into the Baldur's Gate and Vanthampur side of things and after that was over I was left there standing - alright, the plot is done, my city is pretty much safe from this ... why exactly should my level 5 guy go into literal hell to save a city he only vaguely knows about without the slightest inkling on how to get back and only a very vague inkling on how to get there specifically? Oh sure, there is the thing about the missing overlord, but my character did not have a reason to care about him specifically. And the other characters were even worse, they had been literally pressed into service to end a threat for Baldur's Gate, and that threat was ended. I don't know if my GM did not see something, but if the player's had not contorted quite a bit to go along with the plot, some characters' natural response should have been to say "Hahahahaha no, Good Day to you!", when asked to do this.
My advice: Either rewrite the first 5 Levels of the Adventure completely, have your players start at lvl 5 at Candlekeep or at the very least tie them very strongly to Elturel via background.

Speaking of Candlekeep, there are two distinct Wizard characters, one of whom just says "No idea, talk to this other guy" when asked about a way into Avernus. My advice: Just skip the second wizard. I mean, he is an otter, which I find very cool, but the other wizardess had a cool personality so just have that one be the otter, if you want to keep that detail. Done and done.

The larger point I want to talk about is the Mad-Max-Portion of the adventure, the "drive around Avernus to chase the plot". That was ... poorly done. Now, as I have said, some of that can probably be mitigated by reading ahead and preparing better, but at least as I have experienced it, it went poorly.
It all started with Lulu saying "We have to find this sword of my old angel commander." - "Why?" - "Don't know, feel it would be important to have it" - "Okay ...". (That was before the reveal that Zariel was her old commander). And then it is a lot of "Go to X. I have a feeling/have an partial memory/plainly will not tell you why." So you go to X, do something, get send to Y, do another thing, get sent to Z, do something, get send to A etc. etc. It felt very unsatisfying to always be told. "I cannot or will not help you. But go to C. I bet you find something there." - "Why do you think that will help us?" - *Shrug*
And then the driving part. It had a rad as hell asthetic but the implementation was terrible. The second random wencounter we got into was with some archmage character with an umbrella, who nearly TPKed us and we could just barely get away. So that told us that the encounters would not be balanced to our level and since you cannot know in advance if you have found someone you can fight against, the only option every time you see anyone else is just "drive away as fast as you can". And then a tedious chase sets in, with a lot of rounds of: Driver: "I drive on", Harpooneer: "I shoot"; Everyone else "I wait". Every round. No choices whatsoever. Sometimes there are complications, but they are just "something happens, make a save" still without any choices by the players, except "Do we spend Ressources to enhance our rolls/reroll", to which the answer always is "Yes, until we have none for the day anymore, because we have to get away from this thing that will potentially kill us". At the end I was extremely frustrated with it and my GM just stopped rolling for stuff to happen during the driving portion.
I want to stress, the set pieces, the X,Y,Z,A,B from above, they were pretty cool, solidly designed etc. It was just the way it all holds together that was frustrating.

Also; I personally felt a little starved for loot during that portion of the game, but that could just be because we avoided travelling encounters like the plague.

One last portion I was frustrated with: I am playing an Alchemist Artificer whose round-to-round damage options are designed to be stuff like Firebolt (which everyone and their dog is immune to in hell, which is fair enough, it is hell) and acid splash (which almost everyone has advantage on the saving throw on) or poison spray (both). But that I consider simply a problem with class design, where the Alchimist could just as well pick two elemental damage types to get their bonus on instead of being pigeonholed into fire, poison and acid. Just maybe make your players aware that fire- and poison based spells will of very limited use and that a lot of enemies have advantage on saves vs spell.

All in all there are a lot of good stuff in this module, but I feel it is required that you carefully read it in advance and probably rewrite a good chunk of the framing/overall structure. Most of the NPCs are rad as hell, especially Lulu and Reya Mantlemorn (who came with us to hell because our GM thought we might use a 4th party member) are a very cherished part of the team.

[Sigreid]

Addendum to what I was saying earlier, as a DM I offered the party a way out well before the end of the module and I was really hoping they'd take it.

[Eldariel]

And yeah, addendum to what I said earlier, echoing what everyone else said (and I kinda implied but didn't spell out): you basically have to write the Avernus adventure yourself. You have tools and pieces (cool ones!) but as written they at best give you a slideshow.

[Toast]

Actually about to run this for my players. They picked it out of a few of the books I showed them. Our scheduling is wacky so a easy prep game isn't a bad choice for us. Hasn't ruined my opinion of the adventure yet. Being the DM for this I know what they venture to heck it might be boring and might need to pull on makeshift encounters here and there, but I just hope my players have fun.