Arco-flagellation is a form of capital punishment in which the condemned is transformed into a living cybernetic weapon known as an Arco-Flagellant. The punishment is carried out by the Tech-priests of the Adeptus Mechanicus but usually ordered by the Ecclesiarchy or the Inquisition. Arco-flagellation can be used to punish those who have committed any number of crimes against the Imperium of Man, but most commonly it is used to punish those who have expressed heretical views, and utterances or carried out heretical actions.
The condemned are fitted with a variety of cybernetic weapons, including cutting claws, pneu-mattocks and (most popularly) Electro-Flails. Further cybernetic enhancement, usually including canisters for the storage and dispensement of combat stimms, serve to enhance the subjects' destructive power. This is combined with extensive mental reconditioning, ensuring that the subject is reduced to a gibbering berserker with tremendous physical power and no interest in self-preservation. To control them, these subjects are also fitted with a Pacifier Helm, which connects directly to the cerebrum and spinal cord to calm and control the Arco-Flagellant when needed, usually projecting Imperial symbols, litanies, sermons and other elements of the Imperial Cult's theology into the individual's mind and allowing the subject to be only barely conscious of the outside world. Groups of Arco-Flagellants are often used as shock troops by the Ecclesiarchy and the Ordo Hereticus, their pacifier helms being deactivated by a trigger word whenever they are needed to fight.
- Codex: Witch Hunters (4th Edition), p. 28
- Dark Heresy: Blood of Martyrs (RPG), p. 122
- Inquisitor (Specialty Game), pp. 138-139
- The Inquisition: An Illustrated Guid by Nick Kyme, Lindsey Priestley, George Stirling, pp. 8-9
- The Inquisitor Sketchbook by John Blanche, pp. 42-43
- White Dwarf 260 (US), "Inquisitor: Simeon 38X"