Cacodemon

Cacodemon, also called cacofiend or cacodaemon, was a conjuration spell that allowed the caster to summon a powerful demon.

Effects
The spell, which was a perilous exercise, would summon a powerful demon of type IV, V, or VI. The summoned demon would be stronger than a glabrezu, and could be those of the power of a nalfeshnee, a marilith, or even a balor. The name of the demon had to be known by the magic-user. Lesser sorts, such as vrocks and hezrous could not be summoned, as they typically didn't wield the power to have a known name. Greater demons such as demon lords couldn't be summoned, as the spell didn't have the power to do so.

The summoned demon was evilly disposed and in a state of anger. The caster had to be within a protective circle,   or a thaumaturgic triangle of protection from evil. The summoned demon itself had to be confined in a pentacle, or it might go on a rampage and attack the conjurer.

The demon, however, could be forced into service in a number of ways:
 * By threat: The caster could threaten the demon by telling it that they would use the spiritwrack spell upon it. This was a dangerous method, as the smallest error would enrage the demon, making it dangerous to all in the vicinity. The demon would hate the magic-user from then on, due to its forced obedience.
 * By tribute: The conjurer would provide the demon with fresh human blood, through the sacrifice of a single victim, or more. The demon might, however, decide it was more pleasurable to let the summoner die a slow, painful death, instead of accepting the sacrifice.
 * By soul trapping: In the final case, there was no bargaining. Once the soul trapping spell was cast, the demon remained imprisoned until the caster decided. Then the caster could force the demon to perform a service, after which it would be sent back to the Abyss.

If the demon was freed, i.e., by the caster requiring an impossible task of it, it could remain on the plane it was summoned to for up to six hundred and sixty-six days. Casting took one hour per demon level, i.e., to summon a balor, the spell would take six hours. If there was any disruption, the spell failed or the demon was able to escape its boundaries and attack those present.

Components
As well as verbal and somatic components, the spell required a large about of materials. Such materials were:
 * Five flaming black candles; and
 * A brazier of hot coals, upon which a second set of materials had to be burned:
 * Sulphur,
 * Bat hairs,
 * Lard
 * Soot,
 * Mercuric-nitric acid crystals,
 * Mandrake root,
 * Alcohol,
 * Parchment with the demon's name inscribed on it, and
 * A dish of mammal blood (preferably human).

Appearances

 * Video games:
 * Icewind Dale
 * Icewind Dale II
 * Baldur's Gate II: Shadows of Amn
 * Baldur's Gate II: Throne of Bhaal