Blood War

The Blood War is a savage quest for annihilation that ravages the Lower Planes. It's supposed to be a war of tanar'ri against baatezu, but everyone and everything down there seems to be involved. And neither of those "sides" can be trusted, either. A baatezu'll turn stag on his brothers if it'll gain even a little power in the process, and the tanar'ri have always been at odds with each other. In between them all are the gehreleths and the yugoloths, eager to fight for the best-paying side. It's a war that's been going on as long as mortals have lived on the planes, and it's a war neither side has yet to win.

Nobody even knows what the exact goals of the war are. Genocide's the best guess - the tanar'ri and baatezu'll fight each other until there's none left. Why? What berk understands a fiend's mind, can figure out its depraved depths? Maybe the local powers are playing games and making them fight. Maybe they fight just because they want to. Nobody knows for sure how the war started, but a lot of folks figure the Lady of Pain had something to do with it. Some barmy philosophers claim that she's one of them, a fiend now turned stag against all her own kind. Maybe it's true, and maybe it ain't.

The only thing known for sure is that the Blood War's a grim blessing to Sigil. Every move on Sigil by one force triggers a reaction from the other side, since both groups are desperately afraid of the other controlling such power. Sure, it makes traveling the Lower Planes dangerous - especially the battlefields of Gehenna and Carceri - but it keeps the fiends busy.

Note: The above information about the Blood War originally appeared in the Planescape AD&D campaign setting from TSR. Additional information can be found in Hellbound: The Blood War. Its use here is for the purposes of providing context for the campaign only.