The god of magic, particularly evil magic, hidden knowledge and destructive secrets, the gods themselves never knew whose side Vecna was on in the Battle of the Old Ones, as a double agent no one was ever able to prove that he worked with one or the other. While he is despised by most other gods (save Lolth and Talos), his powerful magic allows him skills, spells, and secrets no other possesses, forcing others to ally with him temporarily. He is responsible for the creation of blood magic and necromancy, and created horrors for both sides during the wars. He retreated soon after and none know where he now dwells. Vecna is usually depicted as a powerful magician resembling a desiccated corpse missing his left hand and eye. A constant theme in the ancient tales is Vecna’s never-ending quest for power, ending, should he succeed, with Vecna as the only deity in existence. For now, however, he is not yet powerful enough to conquer all the gods on his own.
Being a secretive cult, there are no real collections of Vecnan teachings. However, copies of the Book of Vile Darkness are highly prized by the cult for Vecna’s role in that work’s development. Each position in Vecna’s cult is named for a certain body part. At the top is Vecna himself, followed by the Voice of Vecna, which can only be filled by Vecna’s manifestation. Next is the Heart of Vecna, the high priest of the cult, a bizarre and ancient creature, indescribable in its unnatural form. Immediately below the Heart of Vecna are two bizarre monsters known as the Hand and the Eye. The Eye of Vecna creature appears as a slender humanoid with an eyeball for a head, whereas the Hand of Vecna appears as a stocky humanoid with a huge left hand where its head should be. Individual congregations are known as organs. Each organ is led by a Thought of Vecna. Lesser priests are known as Memories of Vecna.
Lay members of the cult consist of the Teeth, Fingers, Blood, and Spawn of Vecna. The Teeth of Vecna are made up of wizards, and specialize in arcane spellcasting and crafting magical items for the cult. The Fingers of Vecna consist mainly of thieves, who engage in various forms of subterfuge. The Blood of Vecna are mainly warriors charged with protection and enforcement of the cult and its goals. The Spawn of Vecna are the lowest in the cult hierarchy, and consist of the common people who honor the Lich Lord. The followers of Vecna are few, but consist of those who want power and magic and will let nothing stop them on their quest to acquire it. Rites to Vecna involve blood sacrifice, murder, destruction and torture. However, there exists a secret group known as the Keepers of the Forbidden Lore. Unlike most Vecna worshipers, the Keepers reject most of the nasty and evil rituals and beliefs associated with the God; they worship Him as the God of Secrets, and believe that there is some knowledge too evil for the world to know. They instead hunt down secrets and information they deem to be too dangerous for the world at large and keep it secret in the name of Vecna. This puts them in opposition to mainstream followers of Vecna who regard the Keepers as heretics, and the enemy of most gods of knowledge who believe information should be shared freely.