Are there any other ways to travel between the layers of the Nine Hells besides the River Styx?

Question

I'm planning on creating an adventure where the party become trapped in Nessus, the 9th layer of the Nine Hells, and must make their way through the layers of the Nine Hells up to Avernus, the 1st layer, from which they can find a portal and finally escape.

So far, all I have found regarding travelling between layers is this (DMG, pg. 64):

To reach the deepest layer of the Nine Hells, one must descend through all eight of the layers above it, in order. The most expeditious means of doing so is the River Styx, which plunges ever deeper as it flows from one layer to the next. Only the most courageous adventurers can withstand the torment and horror of that journey.

Avernus

No planar portals connect directly to the lower layers of the Nine Hells, by Asmodeus's orders. As such, the first layer of Avernus is the arrival point for visitors to the plane.

The River Styx, then, seems to connect all of the layers, but I didn't want the party to just sail all the way out, going past all the layers without really experiencing and surviving each one, so I'd rather not use the River Styx if at all possible.

Are there any other ways to travel from one layer of the Nine Hells to another, ideally in descending order (i.e. 9th to 1st)?

This will be for D&D 5e, but information from any previous editions is welcome. If the Hells differs between editions, then assume Forgotten Realms (although information from other settings won't be rejected for not being Forgotten Realms). I also consider the party's level or what I plan on putting in each layer of the Hells for the party to deal with are outside the scope of the question, although I will note that none of them will have access to plane shift or similar.

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As an example of the sort of thing I'm looking for, Wikipedia's page on Baator says this about Cania:

Many things lie hidden under the ice of Cania: vast lost cities, frozen armies of creatures. The primary portal to access Nessus is through a gaping hole guarded by 9,999 gelugons. At the bottom of the dizzyingly deep pit is an icy body of water and 1,001 fathoms deep in that is a silvery portal to Malsheem.

However, there are no sources that I can see for this paragraph, so I don't know if any of this is true. But it at least implies that there are portals connecting one layer to another...

Answer 1

As you said you're all right with consulting the lore of previous editions for an answer, I'd suggest taking a look at Planes of Law from Planescape, if you can get hold of it. (Not just for this particular question, but because it has an excellent presentation of Baator as a whole.) Fires of Dis would also be a great reference for Avernus and Dis in particular. The 3e Manual of the Planes also has a good overview of Baator that could help flesh out your planned adventure.

Anyway, on your particular question. According to a map provided in Planes of Law, as well as the individual descriptions in separate layers, there are the following inter-layer paths between layers (any without descriptions are referenced only on the map):

• Avernus -> Dis: On foot by passing through a massive gate within Tiamat's realm, or via a portal from the city of Darkspine to the City of Dis.

  • Page 14, PoL: Baator

    The Styx runs right through the middle of Avernus. It used to be right on the edge of the layer, but, due to the success of the recruiting plan for the gate-towns like Ribcage and Darkspine, Baator's been gaining territory.

  • Pages 16-17, ibid.

    Tiamat, the Lady of Dragonkind, guards the only known stable entrance to the next layer. It's only through her lair that one can arrive in the verdigrised plains near the Iron City of Dis. The mere thought of approaching her lair's enough to turn back most berks; those that don't go back are definitely the ones with something to prove. It's for this reason that Tiamat (or her guards) even bother to speak with those who approach - they know that the cutter doing it's either extremely powerful, extremely brave, or extremely driven. The guards to the Second Layer appreciate all three of these qualities, and may very well bargain with any planewalker who summons the courage to approach them.

    Of course, if a berk comes in too cocky, the dragon guards might just decide to fry him outright. No one appreciates a sod who doesn't know when to keep his bone-box shut.

  • There's a broad description of Tiamat's lair in Fires of Dis pp.32-33, too much to reproduce here.
• Dis -> Minauros: Portals from the City of Dis to either Jangling Hiter or the City of Minauros.
• Minauros -> Phlegethos: Portal from the city of Minauros to the city of Abriymoch.
• Phlegethos -> Stygia: Portals from Abriymoch to the city of Tantlin.
• Stygia -> Malbolge: Portals from Tantlin and the divine realm of Ankhwugaht (Set's realm) to unnamed locations in the latter layer (as Malbolge has no settlements).
• Malbolge -> Maladomini: Portals from an unnamed location to the city of Malagard.
• Maladomini -> Cania: Portals from Malagard to the city of Mephistar.
• Cania -> Nessus: The portal you mention referenced in Wikipedia, which was also referenced in this work.
  • Page 25, ibid.

    The only known portal from Cania to Nessus (the ninth layer) leads directly to the fortress Malsheem. To enter the portal, a body first has to get to the bottom of a deep glacial pit in Cania. Then, he has to beat off the 9,999 gelugons standing guard at the portal. Assuming a berk somehow gets past this little obstacle, he must plunge into the icy lake at the bottom of the pit and swim downward through the near slush. Swimming is no problem for fiends, who don't really need to breathe anyway, but the 1,001 fathoms a mortal has to swim through might prove rather...difficult. At the bottom of the lake is a portal of ice and corrupted silver, and through the portal is Malsheem.

Further, there are direct portals from the Outlands to the city of Grenpoli in Maladomini, as well as from Sigil to both Grenpoli and Malagard. And of course, the main portal from Ribcage in the Outlands to Darkspine in Avernus. From Planes of Law: Baator, page 5, a general description of the state of portals out of Baator:

Most of the known gates [out of Baator] are two-way and are extraordinarily well guarded, preventing both entrance and egress. Anyone hoping to escape via these gates had better think twice, because the baatezu won't when they catch the poor sod. Most of these portals are build inside the fortresses of the major fiends of the layers. No one knows if the fortresses sprang up because of the portals, or if the portals just happened to appear in the fortresses after construction. 'Course, no one's really asking.

And from page 4, a description of the gate between Ribcage and Darkspine; this is from the perspective of entering Baator, but there's still some relevant portions:

The best route in is via a gate located in Ribcage, that "quaint little village" on the edge of the Outlands. The Cursed Gate, as it's called, is in a heavily fortified part of town; in fact, it's accessible only through the citadel of Lord Paracs, the ruler of Ribcage.

...

...the lord of Ribcage and the baatezu guards on this side of the gate have come to a tidy little agreement, one that profits both sides and doesn't bend the laws too far. Basically, the two parties bob travelers through the gate for whatever they can get...

Also, just as a note that's not especially relevant for you, earlier works suggested that the River Styx only connected to Avernus (as it connects to the first layer of all the Lower Planes) and Stygia. Of course, this isn't binding on later lore by any means, and that passage in the 5e DMG definitely does suggest otherwise as of 5e.

Answer 2

You can just walk

As the book says, the River Styx is just "the most expeditious" way to travel between the circles. But you can still walk. It's just slower, and you're more likely to run into fiends.

Since you're planning for them to travel from Nessus to Avernus, they can't use Styx anyway, as it flows from Avernus to Nessus, the wrong direction for your party.

Answer 3

Yes, the Infinite Staircase will connect to the different levels of the 9 hells. There may also be pre-existing portals connected to a specific layer of the 9 hells.

The DMG section on the Outer Planes has two big caveats that we can drive our caravans through down to the lower levels of the Nine Hells:

1. It states (emphasis mine):

   Planar portals don't connect to the lower levels of the Nine Hells by Asmodeus' orders

   • If planar portals couldn't connect to the lower layers, there would be no reason for Asmodeus to make this order. As a result we infer two things:
     1. Asmodeus has told the other lords that they are not to allow the creation of planar portals on their layers (aside from Avernus).
     2. Planar portals can be connected to the lower layers...they just aren't created by the native denziens, who would likely work very hard to permanently close/guard any that did exist due to the aforementioned orders.

2. The Infinite Staircase section states

   [...] on any given plane, there can be multiple doors to the Infinite Staircase, though entrances aren't common knowledge and are occasionally guarded by devas, sphinxes, yugoloths, and other powerful monsters

   • This is certainly one type of portal (using the literal meaning of the word portal to mean door) that connects different planes, which is explicitly designed to connect to every plane of existence.

Getting to those portals may be a task in and of itself

Travel within the Outer Planes is explicitly something that is changeable by the rulers of those planes. The DMG has this to say about distance, with a specific relevant example for the Nine Hells:

Distance is a virtually meaningless concept on the Outer Planes. The perceptible regions of the planes can seem quite small, but they can also stretch on to what seems like infinity. Adventurers could take a guided tour of the Nine Hells, from the first layer to the ninth, in a single day — if the powers of the Hells desire it. Or it could take weeks for travelers to make a grueling trek across a single layer.