D.I.O. Abyssal Thunder Run

I mentioned a while back that I think there is a trick missing in approaches to the lower planes and another idea has been scratching at my mind. Following Grumpy Wizards steer - if we want it done, we'll have to do it ourselves.

This is one that builds out from the infernal war-machines of Descent into Avernus, nods to some of the other appearances of huge, awful war-constructs that appear through-out Planescape lore (the Ships of Chaos from "In the Abyss", the many mentions of big ruined war machines through out the Blood War lore, etc.) Our core campaign is going to be hex-crawling the Plane of Infinite Portals, juggling wear-and-tear on the War Engine and picking the battles to fight in the deep Abyss

Excerpt from the poster map in Planes of Chaos, by Robert Lazzaretti

The key concept on this is that the party gets sent on a ground level planar run with an infernal engine out of the Nine Hells and off on some mission. The campaign conceit is that you are starting as weaker characters in a powerful machine, and would expect to get more powerful (levelling up) as your machine is battered to pieces beneath you. The trick will be to keep the thing running long enough to get you far enough back out that you can hike home.

Strictly speaking this would be a 'Planejammer' hybrid rather than true Planescape going by our grid but never mind. Parts of this would be to allow a tour of the truly awful parts of the planes, unsurvivable unless you are buttoned up in a dread engine of the Blood War. Parts of this would be to give a big, charismatic vessel that would not be easily replaceable - they get one and have to manage it.

Our hook could be something like the Devils wargamed the mission and realised they cannot be random enough to avoid the Demons so they have contracted some mortal mercenaries to run this expedition. The pay will be incredible, the strings attached minimal, the deal offered altogether too good to be true - which should give the party clear warning of how hazardous this run is.

The mission itself, could vary from the rescue of some force of law that the devils are happy to see out of the clutches of chaos, to the disruption of a demons plot to the assassination of some traitor.

Alternatively the mission could be the quid-pro-quo for the forces of Hell to stop something elsewhere. They are currently creating a 'firebreak' against an abyssal offensive by unleashing horrific destruction somewhere - but if you were willing to kill that traitor or otherwise weaken the forces of the Abyss, they would not need to. Of course, perhaps they started all this mayhem to get to exactly this negotiation position.

Maybe the party are card-carrying Blood War mercs in good standing, maybe this is their 'last mission before they get out', maybe they have to do this or they never get out. With a little session zero twiddling we can get everyone on board in a way that makes sense.

For the campaign itself, while Gehenna and Carceri are not going to work too well with this, a run across the Grey Wastes before the dive into the Abyss could fit well. A run across Oinos the Battle Plain, where one can only make progress if you abandon hope of getting there could be an interesting opener - capped off with facing down/smashing past some Iron Fortress of yugoloths, a chance to demo the crushing power of this fully-functional Infernal machine

Next into the Abyss and the Plain of Infinite Portals
- here we patch in an 'Abyssified' version of Alexandrians Avernus Hexcrawl. I would steal that structure, patch in a greatest hits of ideas from the NOD magazine Hell-crawls
- we will return a few times here as it gets used as our nexus for accessing the rest of the Abyss

Then we get to our sight seeing
Layer 12 - Twelvetrees will get a pass through for spookiness
Layer 23 The Iron Wastes - a glacial expanse
Layers 45-47 Azzagrat - Graz'zts tri-planar realm
- Rauwend the wind-swept steppe
- Shadowsky with its luminous ground
- Voorz'zt of the icy purple fires
Layer 68: The Swallowed Void - barren and completely airless - making a challenge of managing how much of the Infernal Engine remains air-tight
Layer 69: Gibbering Hollow / The Crushing Plain - drive through shoulder to shoulder Manes
Layer 73: The Wells of Darkness - a rocky plain under a dim blue sun with scattered elevations surrounding pools of a black liquid, watched over by the crumbling fortress of Overlook. Used by demon lords as a prison - could be the mission destination.
Layer 100: The Barrens - an enormous expanse containing ruins of all past and future civilizations.
Layer 181: The Rotting Plain
Layer 348: Indifference- a frigid and sterile rocky plain filled with pinnacles and gorges, under a sky of red clouds and a constantly frosty air.
Layer 377: Plains of Gallenshu - a plane of continuous, aimless motion and decay
Layer 566: Soulfreeze - a permafrost layer with an advancing glacier, with malevolent cold said to be capable of freezing creatures' thoughts and emotions

All the above are a collection of 'plains' type realms; ones here the Infernal Engine could be driven across. This need to stick to a terrain type forces them to weave a strange path through the layers of the Abyss.

First idea for format would be to give the players the list of planes above, an initial target in Graz'zts realm of raiding one of his palaces to find the location of the real target.

The campaign would run -
Depart
Travese Oinos >>
Plane of infinite portals >>
random abyssal plane >>
Azzagrat (get info) >>
random abyssal plane >>
Plane of infinite portals >>
random abyssal plane >>
target location (Wells of Darkness?) >>
random abyssal plane >>
Plane of infinite portals >>
Traverse Oinos again, battered >>
Glorious success

The 'random abyssal plane' would be player choice which ones they want to use and in which order. They cannot go direct from Infinite Portals to Azzagrat or the target due to those main gates being fortified so they have to 'go around the back' through these random abyssal planes. They get to pick which ones they want to face at all and in which order. There are nine options above, four of which they would need to use.

Clocks would play a big thing; they have to keep moving or the demons, disorganised as they are, will catch up to them and tear them to ribbons. This again forces the balance between hammering through obstacles with the Infernal Engine or dismounting to deal with it. Tick Tock. Once you exit a realm, that realm is 'hot', you cannot go back there. I would have to have a good read through my Band of Blades to figure out if there are mechanics to be lifted from that.

An alternative take on this would be to recut the AD&D Planescape module "In The Abyss" and turn things around - the Ship of Chaos *is* the transport needed for this, first that has to get found and commandeered and then used to navigate deeper into the Abyss to carry out whatever the mission is. The big difference here is the Ship of Chaos can fly and so all the Abyss opens up as options busting open our more manageable sub-set of 'driveable' planar plains.

For a truly epic mess, maybe some demons have found and captured the Tyrant of War from Path of the Planebreaker and the Ship of Chaos is needed as an equivalent mega-weapon to go up against it, deep in the Abyss where they are keeping it hidden.

Inspirations are things like the BOLO stories or OGRE from Steve Jackson Games - the hyper-tech AI tanks of the far future can crush any given opponent with ease - but after the dozenth, the hundreth, etc. the damage piles up and eventually even these titans of the battlefield fall.

"33" - the opening episode of the reboot Battlestar Galactica would be another. Every time they cross to a new plane the clock restarts on how long it takes the locals to figure out there are intruders and get after them.