As mentioned in The Role of Devils, there are 45 families, organized into 5 territories. Most families are named for the arch-devil that occupies the role of Don; exceptions include the Grigori and the Hinn. The territories and their constituent families are described below.

Thoraz

They mainly work for the angels; only the weaker ranks interact with mortals. Heavily involved in elemental planes. Politically conservative. Based in the Machinarium of the Celestial City.

Families

  •  Ala (NE): Known for driving hard bargains. Greedy, he works his subordinates hard and rewards ambition, as long as that ambition doesn't threaten him.
  •  Barong (NG): Associated with lions; her Family specializes in anti-demon operations.
  •  Charun (LN): Dour and quiet, specializes in anti-undead operations
  •  Culsu (N): Known as the Doorwarden, this Family controls passage from the mortal plane into Shadow.
  •  Grigori (N): This family specializes in scrying and spying on creatures. Led by an imp whose desire for information has given him lots of blackmail material. Unlike most of the territory, they're neutral like arms-dealers are neutral--they supply both sides with information.
  •  Malphas (LN): This family specializes in construction and is dominantly involved in maintenance of the Celestial City. Only rarely summoned to the mortal plane.
  •  Marchosias (LG): Judge of fair battles and duels. Considered stick-in-the-muds by others.
  •  Pelesit (N): Specializes in defensive operations, provides combat troops for mortal-plane operations.
  •  Valac (CN): Finder of Treasures (even other people's treasures). Scrying for objects.

Mara-deva

Many succubi/incubi. 2nd-most-commonly summoned. Corruption/seduction/deception over brute force. Politically progressive. Based in Mara.

Families

  •  Akvan (CN): Sexual desire, beauty, seduction. 
  •  Abyoza (CE): Envy, Jealousy
  •  Bakasura (LE): Hunger for power
  •  Drekavac (NE): Fear
  •  Forneus (LE): Desire for good reputation, deception (PR)
  •  Ipos (NG): Courage, Wit
  •  Lempo (CG): Love, erratic behavior
  •  Pruflas (CE): Contention
  •  Shax (CE): Theft

Chou

Most often called for combat. Straight-forward and brutal. Respect strength. Politically conservative. Not fond of mortals (or anything they consider weak). Based in Ghenna.

Families

  •  Aeshema (CE): Rage/wrath/anger
  •  Angra Manyu (CE): destruction
  •  Aseg (LE): Extremely ugly, army of rock demons. Defensive.
  •  Gualichu (NE): Possession
  •  Hinn (N): Fire, Dogs
  •  Kroni (CE): Annihilation, enmity to everything
  •  Kumbhakarna (LN): great and noble warrior
  •  O Tokata (NE): Death, unquiet dead
  •  Zagan (LE): King, transformation, conquest

Leiutis

Least warlike, most likely to form familiar pacts or Warlock pacts. Frequent users of blackmail. Politically progressive. Based in Aaru. Smallest territory in numbers.

Families

  •  Abraxas (LN): Planar Knowledge
  •  Allocer (N): Art, Magic
  •  Beleth (CG): Music
  •  Danjal (CN): Instruction, Fire
  •  Orobas (CN): Divination, Truth
  •  Phenex (NE): Deception
  •  Puloman (N): Alchemy
  •  Ravan (N): Religious knowledge
  •  Ukobach (N): Gastronomy

Ka-Kola

Not cohesive. Each family is independent. Wide variation. Politics as marked. Based in Naga Padoha, but present all over.

Families

  •  Anzu (CN): Monstrous creatures (magical genetics, non-human). Unaligned (apathetic)
  •  Arunasura (CE): Hypocrisy, god-hater, Unaligned (kill them all)
  •  Bukavac (N): Watcher over the waters, Leviathan, Unaligned (apathetic)
  •  Boruta (N): Guardian of forests, Unaligned/Conservative
  •  Dzoavits (CN): Volcanoes, Cannibalism, Unaligned (kill them all)
  •  Leyak (CN): Crossbreeds (human), Progressive
  •  Namtar (N): Disease/medicine, Progressive
  •  Surgat (CN): Opener of ways, counterpart to Culsu, Conservative
  •  Toyol (NE): Curses/curse removal, Progressive