The Blood War Has Four Origin Stories

John Milton gave Hell one rule in Book II of Paradise Lost: "Devil with devil damned firm concord holds." His fallen angels argue, but they never turn on each other. Their only war is with Heaven. Dungeons & Dragons used several of the same names and built its Lower Planes on the opposite idea. Its devils and demons fight a war of annihilation called the Blood War. The books that tell this story do not agree on why it started. Here is the record.

Milton's Hell Was One Nation

In Paradise Lost, Satan's rebels lie nine days vanquished in the fiery gulf, a lake of fire. Satan has taken a third of Heaven's angels with him. Mammon's crew builds Pandemonium, a golden palace, in an hour. Then the peers debate. Moloch says "My sentence is for open war." Belial argues for patience. Mammon wants to build a rival empire out of Hell's gold. Beelzebub wins the vote with Satan's own plan: leave Heaven alone and corrupt the new race called Man.

Each speaker wants something different, but they all aim at the same enemy. Milton's Hell has factions and no civil war. That is the version D&D took apart.

The Names Became Archdevils

The first edition Monster Manual (1977) brought devils into the game. Its arch-devils were Asmodeus, Baalzebul, Dispater, and Geryon, drawn from Hebrew and Christian figures and their literary versions. Wikipedia notes that Asmodeus is named partly for the fallen angel in Paradise Lost. In 1983, Gary Gygax's article "New Denizens of Devildom" in Dragon #75 added Mammon, Moloch, and Belial. All three also speak at Milton's council, though Wikipedia traces Mammon to the Bible and Spenser's Faerie Queene rather than to Milton. The Monster Manual II reprinted them that year.

Devils were not the first fiends in the game. Don Turnbull, reviewing the Monster Manual in White Dwarf, compared them with "the Demons we already know." The books set the two apart. Devils are lawful evil and live in a strict hierarchy in the Nine Hells. Demons are chaotic evil, cruel and arbitrary, native to an Abyss that the books call theoretically infinite. One early article, "The Politics of Hell" in Dragon #28 (1979), had Asmodeus overthrow Beelzebul, who had overthrown Satan. That article sits outside later canon, but it shows how fast Hell got politics.

The Rename and the War Arrived Together

During the 1980s, critics called the game a doorway to Satanism. A televangelist described the first edition Deities and Demigods as "exactly like witchcraft." TSR responded by dropping the words "devil" and "demon" from second edition, and Asmodeus did not appear at first.

The fiends came back in the 1991 Monstrous Compendium Outer Planes Appendix under new names. Devils became baatezu, demons became tanar'ri, daemons became yugoloths, and demodands became gehreleths. Wikipedia says the creatures did not change in any basic way. The same book introduced the Blood War, which Wikipedia describes as a war of annihilation between baatezu and tanar'ri, absolute, all-encompassing, and virtually eternal. The sources never say the war was invented to give the renamed fiends a story of their own. They only show that both arrived in the same book.

Third edition brought back "devil" and "demon" and kept "baatezu" and "tanar'ri" as subtypes, so it could speak to players of both editions.

Planescape's Front Lines

Planescape covered the war in many books, most fully in the 1996 boxed set Hellbound: The Blood War. Trenton Webb of Arcane magazine wrote that "the fate of all the planes hangs on its outcome."

The two armies fight in opposite styles. True tanar'ri, such as balors (first printed as Balrogs) and six-armed mariliths, push weaker demons around and herd them into makeshift armies. The baatezu fight by rank. Pit fiends command, and lemures, mindless and tormented, are thrown away as cannon fodder. Later books added orthons, foot soldiers who specialize in killing demons, and hellfire engines, cold iron constructs built to fight demons and celestials.

A third side profits from the war. The yugoloths are neutral evil fiends from Gehenna and the Gray Waste, and they sometimes serve both sides of the war. Night hags, as far back as the 1977 Monster Manual, turn slain evil mortals into larvae and sell them to demons and devils. The devil entries say Hell treats mortal worlds as tools for the Blood War. The editions disagree even on the mercenaries. Fourth edition counted yugoloths as demons, so the mezzoloth became the mezzodemon. Fifth edition gave back the old names.

Four Origins

Law against chaos. Fiendish Codex I: Hordes of the Abyss (2006) calls the war an offshoot of the primordial battles between law and chaos, continued out of violent, sadistic stubbornness. This version has no villain and no plan.

The angel who became a devil. Fiendish Codex II: Tyrants of the Nine Hells (2006) makes Asmodeus the bravest and most beautiful of angels. The lawful gods made him to fight demons. After eons of war he and his soldiers grow to look and act like the enemy. The gods put him on trial, and he argues, correctly, that he broke no law. He invents punishment and gets the gods to sign the Pact Primeval, which gives the devils Baator and the souls of the wicked. When the gods see Heaven emptying, he tells them to "Read the fine print." The Codex itself says this account does not tell the whole truth and may be self-serving revisionism. Wikipedia adds that Asmodeus was in fact cast out, and his wounds from that fall still bleed.

The war as cover. Guide to Hell (1999) revealed that Planescape's unnamed Lord of the Ninth was Asmodeus. It treats the Blood War as a distraction from his real goal, which is taking divine power and reshaping the multiverse. The same book names him Ahriman, twin of Jazirian, the god of the couatls. His plan is atheism: if belief fails, the Outer Planes fail, and he remakes them alone.

The stolen shard. Fourth edition makes Asmodeus an angel of a god called He Who Was. After the Dawn War he guards Tharizdun's prison in the Abyss. There the demon lord Pazuzu encourages his rebellion and helps him take a piece of the shard of evil at the Abyss's heart, which becomes the Ruby Rod. Later official material describes what Asmodeus holds differently, as a piece of the elemental chaos Tharizdun used to create the Abyss, and says the demons want it back. Wikipedia also credits fourth edition's Manual of the Planes with cooling the war into a smoldering cold war, though that claim has no citation.

Zariel Plays the Story Again

Zariel was an angel of Celestia charged only with watching the Blood War. She raised an army, charged into Hell, and fell. Asmodeus made her ruler of Avernus, the first layer. The pit fiend Bel deposed her thousands of years ago, but he handled the war badly and she took Avernus back. She was first mentioned in Guide to Hell (1999), got a stat block in Mordenkainen's Tome of Foes (2018), and is central to Baldur's Gate: Descent into Avernus (2019). Her defense: "I rose to shoulder a cosmic burden." She is the Fiendish Codex II origin happening a second time.

Firm Concord, in Secret

Milton may be right after all. In fourth edition, the King of Hell carries a weapon a demon lord helped him take, and Wikipedia reports that it is said he still owes Pazuzu a favor. Every origin above may be propaganda. Andrew Zimmerman Jones of Black Gate called the war a fight over "who gets claim on being more evil."

Using It at the Table

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