This article was first broadcast in Episode Ninety on 25th September 2019.
Ryu: All right, so lets cover this again. The Blood War is not…
Lennon: A thumb war where both people have pricked their thumbs.
Ryu: And it’s also not
Lennon: A water balloon fight where the balloons are filled with red-colored water.
Ostron: Someone misinterpret the topic again?
Lennon: Well are you going to tell us what the Blood War *is* then?
As we mentioned in our primer on the Nine Hells, Avernus is the front line in the eternal conflict between Devils and Demons known as the Blood War.
For the most part, the aggressors are the demons, who are constantly trying to push out of the Abyss and assault the Nine Hells, and the Devils are reacting to these offensives and pushing them back, occasionally counterattacking and taking the fight to the Abyss.
The war is mostly a cosmic stalemate. The demons are a self-replicating horde of violent, barely directed monsters while the devils are regimented tacticians with strategy and ingenuity on their side. Without external influence, the devils have the advantage most of the time because their tactics always beat a comparable number of demons. The problem is the devils have other things to do, like tempting mortals and getting contracts signed, so they rarely commit their whole force. Most demons, on the other hand, are attracted by violence and ignore odds, so when the fighting gets more intense, more demons show up, and that continues until the devils are able to mete out more destruction than the demons can recover from and their numbers dwindle.
The reasons for the war are lost to history but part of it surely has to do with geography, specifically that of the river Styx. Unlike its Greek counterpart, the D&D river Styx doesn’t lead from the Earth to Hell, it leads from the Abyss to the Nine Hells. The river is insanely difficult to navigate, though, and even the demons have to pay merreneloth pilots to ferry them along it. Apparently there are paths in the river that lead to the material plane, but those are difficult to find and navigate even for the pilots, and they apparently aren’t permanent either.
So the demons who wanted to throw down were left with the option to cultivate followers on the material plane until there were enough of them with power and knowledge to create a portal to the abyss, or toss a few coins to a thing with a boat and wait a couple of hours. The demons obviously took the path of least resistance.
Another facet of the war and another reason it keeps persisting is that neither devils nor demons actually die unless they’re killed in their place of origin. Most of the fighting in the war actually takes place on the various banks of the river Styx; apparently the demons only gain enough of a foothold to push into Avernus every 1,000 years or so, so most of the troops in the war aren’t actually dying. If either side pushes to where the other *can* start dying, they tend to be met with overwhelming force faster than they can muster reinforcements; the limitation of needing pilots for the river, and that the pilots have to be paid, keeps either side from transferring overwhelming force to the other’s home territory.
So other than the idea that “I’m glad they’re fighting each other and not us,” what does the Blood War have to do with the material plane and adventuring groups? Well, most of the things demons and devils accomplish on the material plane are supporting their efforts in the war somehow.
Demons can spawn from anywhere abyssal or demonic influence is present, so more demonic incursions that are flourishing on other planes means more possible troops for the demons. Similarly, devilish cults attracting followers translates to more soldiers for the devils’ ranks.
Apart from checking attrition, two other things all the demonic and devilish entities are looking for on other planes are passages and weaponry. Divine weapons that break through demonic or devilish resistances or are simply overwhelmingly powerful in ways the devils or demons can’t emulate are sought after by both armies, and the cultists that serve the masters of them. Also, any way to get a large number of troops from the Hells to the Abyss or vice versa that doesn’t involve dealing with the River Styx would be invaluable to whichever side located and seized it first.
Because resources on the Material Planes can influence the balance of the conflict, some people such as Mordenkainen have adopted a philosophy dedicated to monitoring and maintaining it. Often this means blocking or fouling their efforts on the material planes, but sometimes they also employ questionable means. For example, if they’re aware of a devilish offensive that has broken through and the demons are falling back in the Abyss, agents of maintaining the balance might allow a demonic incursion to flourish in a city and will actively work against people trying to bring it down. Similarly, if they know the devils need reinforcements, they might find a large cult devoted to a devil and simply kill all of them to ensure the souls go to the Nine Hells and can be used to bolster their ranks.
Ultimately they believe the balance has to be maintained because they don’t think any other force stands a chance against either army. The material planes don’t have the power or coordination in most cases, and the other planes are generally less populated. Even the forces of the gods in Celestia are generally much smaller than their lower counterparts since the benevolent gods aren’t usually taking every soul devoted to them and making them into soldiers.
It’s suggested that a combined force of dragons might be a deciding factor, but with Tiamat stuck in the Nine Hells many wonder if that’s even possible. She clearly has some sort of tie to Asmodeus, so while dragons aren’t known to participate in the Blood War currently, if the devils were to emerge victorious, no one knows if Tiamat would be willing or even able to oppose the leader of the Archdevils.
In general the Blood War is another one of those bits of lore it’s very easy to ignore if you want. Even getting anywhere near the actual conflicts of the war is a quest line in itself, and one adventuring group is unlikely to matter in the grand scheme. However the information here might supply some extra depth to a demonic or devilish encounter and could provide other avenues of thought beyond “bad demons, begone!”
Lennon: Hang on, do demons or devils even bleed?
Ostron: Um…some of them might. A lot of the demons kind of just ooze…
Lennon: So why’s it called the Blood War then? Shouldn’t it be something like The Underconflict, or War of the Styxian Termini?
Ostron: Oh I kind of like that last one.
Ryu: Right well you guys can write Mordenkainen a note about how he stinks at naming things, but do it later; right now we’ve got a bunch of notes from listeners in the Scrying Pool.