In the Dungeons & Dragons fantasy roleplaying game, the Blood War is an eternal conflict between the fiends of the Lower planes. The Tanar’ri are the demonic forces of the Abyss, an evil plane of chaos. Representing the equally evil but lawful realm of Baator are the Baatezu, the dominant caste of devilkin. Neutral evil Yugoloths play both sides against the other. The Blood War has raged on since the Age Before Ages, a dark period when the Prime Material Plane had not fully developed.