A demonologist is a mortal who has devoted his life to the study of demons. He is practiced in dealing with them, fighting them, and using them for his own gain. He even gains some demon abilities due to his studies and devotion to the fiends of the Abyss. Demonologists are always evil, although they might not think of themselves as such. No character can get so close to the mind of utter corruption and come away unchanged.

Most demonologists were once wizards or sorcerers, although bards who delve into evil lore also frequently meet the requirements of the class. Demonologists see themselves as researchers and keepers of lore that most people cannot handle. Thus, they often sequester themselves away in libraries of dark knowledge. They attempt to deal with demons on an equal footing—an extremely dangerous undertaking—and rarely interact with mortals. When demonologists see the need, they emerge from their studies and use their dark powers to take or do what they want; then they return to their books and summoning circles. PCs might come into conflict with a demonologist who is after some rare bit of lore or a magic item that they possess. Or the characters might need the help of a demonologist if they are planning to fight demons and need aid or information.

Role: Spell Utility

Characteristics: Those who have devoted their lives to studying demons

Source: Book of Vile Darkness

Game Rule Information

The Demonologist has the following game statistics.

Abilities: Charisma for casting spells and controlling demons, Constitution for when you get hit and need to stay in control and dexterity to avoid it.

Alignment: Chaotic Evil

Hit Die: d4

Starting Gold: N/A

Class Skills

The Demonologist's class skills are Alchemy (Int), Bluff (Cha), Concentration (Con), Decipher Script (Int), Forgery (Int), Intimidate (Cha), Knowledge (arcana) (Int), Knowledge (the planes) (Int), Knowledge (religion) (Int), Listen (Wis), Ride (Dex), Scry (Int), Search (Int), Sense Motive (Wis), Spellcraft (Int), and Spot (Wis)

Skill Points at 1st Level: (4 + Int modifier) × 4

Skill Points at Each Additional Level: 4 + Int modifier

Class Features

All of the following are class features of the Demonologist.

Weapon and Armor Proficiency: A Demonologist is proficient with whatever they were already proficient with prior to taking levels in this class.

Spells: Beginning at 1st level, a demonologist gains the ability to cast a small number of arcane spells. To cast a spell, the demonologist must have a Charisma score of at least 10 + the spell's level, so a demonologist with a Charisma of 10 or lower cannot cast these spells. Demonologist bonus spells are based on Charisma, and saving throws against these spells have a DC of 10 + Caster level. The demonologist like a cleric, has access to every spell on their list, and need not prepare those spells ahead of time, just like a sorcerer. A demonologist casts spells just as a sorcerer does.

Charm Demon Sp: A 1st-level demonologist can attempt to charm a chaotic evil outsider, as described in the charm person spell, once per day. The demon does not get to use its spell resistance, though it can make a saving throw as normal (DC 11 + Caster level).

Quasit Familiar Ex: .A 2nd-level demonologist gains a quasit as a familiar, whether he wants it or not. If the demonologist already has a familiar, the quasit devours it and takes its place, but the character suffers no experience point loss. The quasit is treated as a normal familiar, using the class level of the demonologist as the master's level

Summoning Mastery Su: When a demonologist of 3rd level or higher casts a summon monster spell, it is treated as the equivalent spell of two levels higher for purposes of summoning chaotic evil creatures. For example, a demonologist refers to the Summon Monster IV list for chaotic evil outsiders when casting Summon Monster II. At 6th level, the demonologist refers to the summoning list three levels higher than the one for the summon monster spell he is casting. At 9th level, the demonologist refers to the list four levels higher.

Resistances Su: A demonologist who reaches 4th level gains acid resistance 10, cold resistance 10, fire resistance 10, and electricity resistance 20.

Poison Immunity Ex: A 5th-level demonologist is immune to poison.

Hold Demon Sp: A 7th-level demonologist can attempt to hold a chaotic evil outsider, as described in the hold person spell, once per day. The demon does not get to use its spell resistance, though it can make a saving throw as normal (DC 12 + Caster Level).

Telepathy Su: An 8th-level demonologist can communicate telepathically with any creature within 100 feet that has a language, just as a tanar'ri can.

Dominate Demon Sp: A 10th-level demonologist can attempt to dominate a chaotic evil outsider, as described in the dominate person spell, once per day. The demon does not get its spell resistance, but it can make a saving throw as normal (DC 15 + Caster Level).