I’ll preface this post by making it clear that I thoroughly enjoy the D&D 5E campaign Baldur’s Gate: Descent into Avernus. I think it’s a good story in an awesome setting, that is both ambitious in its scope and simple in its execution. It’s a good campaign. You should run it!

Now that we have that out of the way, there are still – as there always will be when running official campaigns – things I would change about the campaign. In the case of Baldur’s Gate: Descent into Avernus, this is especially the case with Chapter 3: Avernus.

By far the meatiest chapter in the book, Chapter 3: Avernus is where the party will probably spend the majority of their time both in- and out-of-character. It’s a chapter filled to the brim with exotic encounters and fantastical locations, which is awesome.

Save more than 33% on all our DM’s Resources for Baldur’s Gate: Descent into Avernus.

But, it is also a fairly linear chapter, which has the players making one arbitrary choice between two paths, and then following that straight path all the way to their goal (the Bleeding Citadel), leaving it entirely up to the DM when (and if) to introduce additional encounters. This makes the chapter easy to run, but also less exciting than it could be.

In our DM’s resources PDF for Baldur’s Gate: Descent into Avernus, we’ve written quite a bit about this, offering ways to tie the Path of Demons and Path of Devils together to give the party some choices about where to go and who to speak to.

In this post, we’ll elaborate even further upon this idea, presenting a full-fledged blueprint for turning Avernus into an actual sandbox, where the party must determine on their own how to reach their goal!

The Principles of a Sandbox

The main difference between a linear story and a sandbox is the players’ feeling of agency – the perception that they have choices and that those choices matter to the story. A linear story offers a straight path and (hopefully!) clear motivation, but doesn’t allow for alternate routes to success. A sandbox allows the players to choose their own path through the narrative by giving them several valid ways to reach their goals.

Alright, that sounds easy enough. We’ll just dump the party in Avernus, let them know about Zariel’s Sword, and see what they choose to do! Unfortunately, it isn’t quite that easy.

Having infinite choices without any information about how to make the right choices isn’t freedom – it’s frustration. Especially in a place as unfamiliar and abstract as Avernus. No, to create a fun sandbox, we have to feed the players just enough information for them to realize that there’s several ways to accomplish their goals.

So, how many options should the characters have in the perfect sandbox? As a rule thumb, three options is a good goal to aim for. To the players, three different – but equally viable – ways to progress will often feel like freedom without being overwhelming.

Our purpose, then, is to take the encounters and locations described in Chapter 3: Avernus and rearrange them in a way where the characters have at least three ways of progressing forward at (nearly) all times. So, how do we do that?

Building the Sandbox

Before we can put the toys into the sandbox and let our players go crazy, we first have to build a frame for our box. We’ll start by taking a look at the existing framework of Chapter 3: Avernus and see how we can reuse the planks supplied to us there.

The Basic Structure

As suggested in the book, we’ll start the chapter off with the characters going to Fort Knucklebone and interacting with Mad Maggie. Fort Knucklebone is an interesting location with fun NPCs, which has the added benefit of giving the characters an early opportunity to acquire infernal war machines and information about Avernus. We also won’t change the chapter’s endpoint, the Bleeding Citadel, where the adventurers will find the Sword of Zariel.

So, it’s what is in-between these two points – Fort Knucklebone and the Bleeding Citadel – that will constitute our new structure for Chapter 3: Avernus.

The Fallen Three

To fill out the structure, we’ll start by walking backwards from the Bleeding Citadel, the characters’ final destination. The party will have learned about the Bleeding Citadel from the Helm of Torm’s Sight in Elturel, and have traveled to Fort Knucklebone because they need find out where the Bleeding Citadel is.

Here we scrap what is in the book – the Dream Quest doesn’t end with Lulu pointing them toward some random hill, and then to the Demon Zapper or the Spawning Trees.

Instead, the party’s Dream Quest with Maggie will allow them to see the three important NPCs who know the way to the Bleeding Citadel: Olanthius (Crypt of the Hellriders), Haruman (Haruman’s Hill) and Bel (Bel’s Forge).

These three NPCs share a close connection to Zariel and the story of her fall, making them excellent choices for delivering the final information the party is after. Don’t worry, we’ll go into more detail about how information about these NPCs can be presented to the party in Part 2 of this series on ‘Avernus as a Sandbox’.

For now, we’ll call these NPCs the ‘Fallen Three’ and add them to our structure:

Start – Fort Knucklebone

Fallen Three Crypt of the Hellriders Haruman’s Hill Bel’s Forge



End – The Bleeding Citadel

Of course, Mad Maggie doesn’t simply point the party directly to the location of one of these ‘Fallen Three’. That would be both too convenient and too short – remember, the characters are supposed to go from 7th to 11th level during Chapter 3. However, she (and other sources of information they meet) can help them find the ‘Intermediaries’ – NPCs with the power to locate the ‘Fallen Three’.

The Intermediaries

There are three NPCs who can help the party locate the ‘Fallen Three’ and – in turn – the Bleeding Citadel: Mordenkainen (Tower of Urm), Red Ruth (Bone Brambles) and Mephistopheles (Mirror of Mephistar). Wizard, witch and fiend, these intermediaries are all powerful and resourceful spellcasters.

This gives us the following structure:

Start – Fort Knucklebone

Intermediaries Tower of Urm Bone Brambles Mirror of Mephistar

Fallen Three Crypt of the Hellriders Haruman’s Hill Bel’s Forge



End – The Bleeding Citadel

Blood Pay

Now, this is certainly a start. The party has a meaningful choice about which of the three ‘Intermediaries’ to seek out, and subsequently a choice to make about which of the ‘Fallen Three’ they want to ask about the Bleeding Citadel.

However, there’s still many encounters in Chapter 3: Avernus that deserve to see some use. To fill out our sandbox, we’ll insert a fetch quest after the ‘Intermediaries’ – a task that needs to be completed, before the NPC will help the party find Olanthius, Haruman or Bel.

Luckily for us (and our preparation), Mordenkainen, Red Ruth and Mephistopheles, are all after the same thing: blood from powerful creatures inhabiting Avernus. This leads the party to at least one of these encounters:

Arkhan (Monument to Tiamat)

Uldrak (Uldrak’s Grave)

Ubbalux (Obelisk)

Shummrath (Pit of Shummrath)

But, finding these creatures isn’t all the characters have to do.

To get Tiamat’s blood from Arkhan, they’ll have to travel to his tower and then to the Monument to Tiamat, where they must either take the blood by force, or sacrifice a good-aligned creature – such as the unicorn from the Demon Zapper.

To transform Uldrak back to an empyrean, they must first help him slay a dragon – which can be found at Arkhan’s Tower.

To release Ubbalux from his prison, they have to convince another sentient creature to willingly take his place – perhaps the chaotic good Krikendolt at the Spawning Trees.

To free Shummrath, the characters must first secure explosives from the Firesnake Forge at the Wandering Emporium.

When we insert our ‘Blood Pay’ fetch quest into the structure, it expands to look like this:

Start – Fort Knucklebone

Intermediaries Tower of Urm Bone Brambles Mirror of Mephistar

Blood Pay Arkhan’s Tower → Monument to Tiamat → Demon Zapper Uldrak’s Grave → Arkhan’s Tower Obelisk→ Spawning Trees Pit of Shummrath→ Wandering Emporium

Fallen Three Crypt of the Hellriders Haruman’s Hill Bel’s Forge



End – The Bleeding Citadel

Final Task

To further pad out our structure, we’ll also place a task after each of the ‘Fallen Three’ – something that needs to be done before the party can learn the way to the Bleeding Citadel. Here we won’t give the party multiple choices, since they’ve already had quite a bit of agency (and always having three choices can get nonsensical if overdone).

In short summary, Olanthius wants the party to distract Zariel by freeing Kostchtchie (Kostchchie’s Maw), Bel wants the party to find the control rods (Wrecked Flying Fortress), and Haruman won’t tell the party anything, so they’ll have to extract the location of the Bleeding Citadel from his corpse by feeding the dead narzugon to the Sibriex (Sibriex).

When we add these encounters to our sandbox, it looks like this:

Start – Fort Knucklebone

Intermediaries Tower of Urm Bone Brambles Mirror of Mephistar

Blood Pay Arkhan’s Tower → Monument to Tiamat → Demon Zapper Uldrak’s Grave → Arkhan’s Tower Obelisk → Spawning Trees Pit of Shummrath → Wandering Emporium

Fallen Three Crypt of the Hellriders → Kostchchie’s Maw Haruman’s Hill → Sibriex Bel’s Forge → Wrecked Flying Fortress



End – The Bleeding Citadel

… and even more filling

There’s still some encounters left in Chapter 3 that we aren’t using, however. We still haven’t used the Arches of Ulloch or the Hellwasp Nest. Additionally, there’s also the Wandering Emporium and Smiler the Defiler, both of which offer cool social encounters and nice ways to supply the party with information. Lastly, there’s our own ‘Infernal Bounty’-encounter, which you can download for free at the DM’s Guild.

Arches of Ulloch

In our DM’s Resources for Chapter 3: Avernus, we’ve fleshed out the Arches of Ulloch into an elaborate encounter involving an infernal sphinx. We can fill out the structure a bit more by inserting the Arches of Ulloch as the only way one can actually reach the Bleeding Citadel – also providing a logical explanation to why nobody can find or locate the citadel through other means.

Hellwasp Nest

The Hellwasp Nest can be intertwined with Haruman’s Hill, or used independently as a ‘random’ encounter, that can take place at any time you want to shake things up a bit. If the players are thinking to take rest before they’ve been properly pushed, it might be time for a few hellwasps to descend upon them and steal some valuable stuff (or golden elephants!).

Wandering Emporium, Smiler the Defiler & Infernal Bounty

We can use the last three encounters – the Wandering Emporium, Smiler the Defiler and the ‘Infernal Bounty’-encounter – as means to supply the party with information, so they become aware of the options available to them in an organic way. We’ll delve more into the process of doling out information in part 2 of this series.

All together, a sample structure of Chapter 3: Avernus as a sandbox could look like this:

Start – Fort Knucklebone

Travel Encounter 1 – Infernal Bounty

Infernal Bounty Intermediaries Tower of Urm Bone Brambles Mirror of Mephistar

Travel Encounter 2 – Wandering Emporium

– Wandering Emporium Blood Pay Arkhan’s Tower → Monument to Tiamat → Demon Zapper Uldrak’s Grave → Arkhan’s Tower Obelisk → Spawning Trees Pit of Shummrath → Wandering Emporium

Travel Encounter 3 – Smiler the Defiler

Smiler the Defiler Fallen Three Crypt of the Hellriders → Kostchchie’s Maw Haruman’s Hill → Sibriex Bel’s Forge → Wrecked Flying Fortress

Travel Encounter 4 – Hellwasp Nest

– Hellwasp Nest Arches of Ulloch

End – The Bleeding Citadel

This structure provides us with roughly 10 encounters between Fort Knucklebone and the Bleeding Citadel, while also allowing the players to make meaningful choices at (at least) three critical junctions: choosing which of the ‘Intermediaries’ to seek out initially, choosing what ‘Blood Pay’ to go after, and, finally, which of the ‘Fallen Three’ to seek out.

If you’re like me and want a flowchart, we’ve strung one together for you here:

Putting Everything Together

Now that we have managed to create a new, more sandbox-like structure from the encounters in Chapter 3, we next need to make those encounters and locations actually fit the structure. Several of the encounters will need a little re-shuffling, re-thinking and re-flavoring before they fit snugly. Luckily, this isn’t nearly as much work as writing entirely new encounters and locations from scratch.

We take a more detailed look at each encounter/location in Chapter 3, as well as go into more depth about how you can supply the party with information about the different options that are available to them, in Avernus as a Sandbox – Part 2.

Finally, please remember that everything we’ve written here are just suggestions, so you’ll probably want to change things around to fit your campaign, your players, and your perception of Avernus. All we hope, is that some of the ideas her can serve as an inspiration for your own game.

Until next time – have fun in Hell!

J. A. Valeur