D&D General Abyssal breaches?

[Quickleaf]

My players will be venturing through a desert soon-ish (early this summer) which is plagued by Abyssal breaches.

What would an abyssal breach look like? And how would you model it in the game?

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AFAIK, there is no "correct and official" answer here, so my question is coming from a spirit of creativity, and I'm wondering how you would imagine it. My rough draft take is a blend of borrowing Dragon Age: Inquisition's fade rifts (where once you start the closing process, it takes a minute and/or killing waves of demons) & a custom write up like the supernatural regions in Tasha's Cauldron of Everything. But I'm excited to break outside the usual tropes my mind gravitates toward.

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Surveying the Books: The 5e Monster Manual makes brief mention of a phenomenon called "abyssal breaches", but AFAICT there are no other mentions of such a thing in D&D 5e. The idea seems to be more than just demons controlling existing portals. It's evocative of a planar bleeding effect where one plane bleeds into another, like what the 3e Manual of the Planes describes as planar anomalies such as outpocketing, nested pockets, and minor/major planar bleed.

Relevant excerpts:

Abyssal Invasions. Wherever they wander across the Abyss, demons search for portals to the other planes. They crave the chance to slip free of their native realm and spread their dark influence across the multiverse, undoing the works of the gods, tearing down civilizations, and reducing the cosmos to despair and ruin. Some of the darkest legends of the mortal realm are built around the destruction wrought by demons set loose in the world. As such, even nations embroiled in bitter conflict will set their differences aside to help contain an outbreak of demons, or to seal off abyssal breaches before these fiends can break free.

Signs of Corruption. Demons carry the stain of abyssal corruption with them, and their mere presence changes the world for the worse. Plants wither and die in areas where abyssal breaches and demons appear. Animals shun the sites where a demon has made a kill. The site of a demonic infestation might be fouled by a stench that never abates, by areas of bitter cold or burning heat, or by permanent shadows that mark the places where these fiends lingered.

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Campaign Context: The campaign is set in Fantasy Ancient Egypt, with the world under threat of being dragged into the 48th layer of the Abyss (alternately described as a hellish desert known as the Nerebdian Vast and as Skeliac the Ocean of Tears) by Graz'zt, Demon Lord of Indulgence. However, in the background of this growing chaos, other demon lords have a less significant presence including Baphomet, Yeenoghu, and Pazuzu.

The Abyssal breaches may be tied to specific quests or they may be encountered as a random encounter. The intent is that they can be sealed, albeit it won't be easy to do so, and otherwise interacted with. Demons can crawl through, but the breach probably cannot be used as a portal for those on the Material Plane side - they're more of a one-way deal at best.

 

[prabe]

Have you pondered what the relevant layer of the Abyss is like? My own inclination would be to overlay elements of that onto the surrounding terrain. I'd also expect there to be demons (and/or other Abyssal creatures) emerging from the breach.

Also there's a demon in Mord's (I'm away from my books) that specifically is about turning doors and maybe windows into portals to the Abyss.

Also also, if you have Mord's, you might look at the Lair Effects for any of the relevant demon lords.

If you were looking for specifics, those aren't. Sorry.

 

[TwiceBorn2]

An Abyssal Incursion is described on pp. 24-25 of Ghosts of Saltmarsh... not sure if an Abyssal Incursion is synonymous with an Abyssal breach?

 

[jgsugden]

My main campaign setting has a wasteland continent (the size of Eurasia) that has thousands of portals to the Abyss. The entire continent is plagued by fiends and their allies, and the terrain around each portal takes on the nature of the part of the Abyss connected to it (often for many , many miles). Even the laws of nature can be suspended in these areas, creating zones of reverse gravity, darkness, strange weather, etc....
As my Abyss was created from the Hells when the Far Realm first started to corrupt the Universe, Demons tend to be more creepy and horrific than your 'out of the box' monstrosities. They often overlap with Aberrations, which tend to have a flair inspired by Horror Movies like Hellraiser, Pan's Labrynth, etc... and are all a product of body horror in one fashion or another.

I obviously have not detailed all of the areas, but there are wide ranges of inspiration taken from D&D Lore, Movies, TV and Comics. The portals appeared a thousand years ago in the midst of the most powerful nation in a vast world (12 times the size of Earth, with an equally large 'Dyson Sphere' style underdark). Accordingly, many of these locations are centered around corrupted cities or feature locations (monasteries, churches, universities, etc...)

There is one last bastion of good that has been fighting a hopeless battle to reclaim the continent for a thousand years, but beyond that it is literally "Hell on Earth". Archfiends, Demon Lords, and all sorts of terror pass back and forth through these portals freely. Beyond the Good versus Evil fight, the Blood War spills onto that continent too, although the stakes are less than the Blood War in the Hells (My Abyss and 9 Hells are one plane, with the Blood War being fought by the Demons trying to reclaim the rift to the Far Realm at the center of Asmodeus' realm) because the losers just return to the Hells when they die on the Prime, rather than being recrafted into a Lemure/Nupperibo/Manes/Dretch as those that die in the Hells are.

This zone has featured in the culmination of many of my campaigns. It might be recovering a lost artifact, venturing into the hells via a specific gate, closing a particular gate, etc... One feature of the area is that teleportation magic and planar magic, outside of the gates, does not work there. That causes PCs a lot of problems.

 

[Dausuul]

I would focus on altered landscapes, and on elemental forces in bizarre, malevolent combinations. Rivers of burning ice. Oozing, poisonous light. Obelisks that crackle with black lightning. Glass shards that raise a cacophony of deadly chimes at the slightest touch. The terrain hazards near a breach can kill you before you even see a demon.

(My approach to coming up with these was to take two damage types, mash them up, and try and imagine what the resulting terrain hazard looks like. Fire/cold, radiant/poison, necrotic/lightning, slashing/thunder, etc.)

 

[MarkB]

Well, it may or may not be thematic to D&D's version of the plane, but when I hear "Abyss" I immediately picture infinite unfathomable depths. So how about a way to create that feeling around a breach?

The breach itself is relatively small, maybe an angry swirly vortex a dozen feet across - but it comes with its own gravity, which overwhelms that within the plane it intrudes into across a wide area.

You can feel it even from half a mile away, an odd tilting that throws things slightly off the horizontal. The closer you get, the stronger the effect, until any ground within a hundred feet of the breach is fully turned from horizontal to vertical, with everything falling towards the breach.

The demons that come through the breach all tend to be ones with Fly or Climb speeds, and many of them don't bother to venture far - they just wait at the aperture, ready to intercept anyone who gets too close and topples in towards it.

 

[Quartz]

What would an abyssal breach look like? And how would you model it in the game?

In the 3E book on the Bright Desert (Rary the Traitor?) there are a couple of places - one an oasis - that are intermittent abyssal breaches. IIRC they look perfectly normal; they just 'feel wrong' and you definitely don't want to stay around after dark.

In Iron Crown's Shadow World, breaches are often tied to celestial objects and events and the flows of magic across the land.

 

[Weird Dave]

My adventure Blight of the Demongate contains a table for a Fiendish Blight modeled after the Supernatural Regions presented in Tasha's Cauldron of Everything. My Codex of the Infinite Planes article for the Abyss also includes tables for randomly generating threats and hazards across the Infinite Layers. Either could be useful for you!

 

[Enevhar Aldarion]

Well, we certainly don't want a bunch of naked demons running around, so they should definitely be wearing something below the waist.

 

[QuentinGeorge]

On a larger scale the Worldwound of Pathfinder (Golarian) is an example of a sort of Abyssal breach and the consequences thereof.