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"The Machine Spirit guards the knowledge of the ancients. Flesh is fallible, but ritual honours the Machine Spirit. To break with ritual is to break with faith."

The Warnings, Tenets of the Adeptus Mechanicus
Adeptus Mechanicus Icon

The Cog Mechanicum, seal of the Adeptus Mechanicus.

A Machine Spirit is a supernatural, animistic spirit believed by the adherents of the Cult Mechanicus within the Adeptus Mechanicus and, from their teachings, by most other Humans of the Imperium, to inhabit and control any technology in existence as part of the divine extension of the Machine God known as "the Motive Force."

The functioning, or lack thereof, of any machine is believed to be the result of its spirit's disposition. To keep their Machine Spirits happy and cooperative, operators therefore make numerous ritualised advances to the machinery.

These rituals vary depending on the machine or technology at issue, but in most cases include various maintenance rituals and prayers of function. They may also occasionally include a sacrificial offering or libation. The number of rituals or the size of the offering is increased in value if the machine is large and/or important to some specific purpose.

Machine Spirits are believed to be bestowed by the Machine God and subservient to Him. They are believed to exist in every vital weapon and device used by those who follow the Emperor of Mankind. From bolters to power armour to voidships, the blessing of the Machine God and His subservient Machine Spirits allows for the Emperor's enemies to be defeated.

The term is also applied to the rare instances of machine intelligence allowed to exist within the Imperium, such as the limited artificial intelligences that guide the Space Marines' powerful Land Raider main battle tank, Imperial Knights and Titans, and planetary cogitator networks.

Alien Technology

Because alien technologies do not make observances to their Machine Spirits, many of the tech-priests among the Adeptus Mechanicus see these devices as grave heresies that must be destroyed rather than studied, even if their technology is superior to their Human-manufactured counterparts in operation. This view is not universal, however.

Indeed, many Human colonies near the boundaries of the T'au Empire were found to be using more advanced T'au technology for agricultural purposes during the Damocles Gulf Crusade, and the offending colonists were punished with penal sentences.

However, the general Imperial prohibition on the use or acquisition of alien technology serves the purpose of hindering and punishing those who trade with prohibited xenos species and betray the Imperium. However, certain Imperial officials, notably Radical Inquisitors and Rogue Traders, are often exempt from this prohibition.

Artificial Intelligence

The development of artificial general intelligence -- actual self-aware machines (also referred to as "Abominable Intelligence" or "Silica Animus" in the Imperium) -- is prohibited under pain of execution by edict within the Imperium unless a Human mind is combined with it or serves as part of its mechanism (hence the existence of cybernetic servitors who take the place of robots for labour and defence on most Imperial worlds).

This prohibition was embedded within the agreement between the Imperium and the ancient Mechanicum from the signing of the Treaty of Mars in 739.M30, to ensure that intelligent machines would never again become corrupted by Chaos and rebel against their Human masters. This had happened during the Age of Technology with the constructs known as the Men of Iron, who had launched a star-spanning rebellion, the Cybernetic Conflict, against their Human creators.

However, some machines are allowed a limited form of independent artificial intelligence under the religious guise of having an especially active Machine Spirit. An example of this is the vehicles of the Space Marines. The Space Marines' Land Raider main battle tank can continue to move and fire, albeit with lesser ability, even if its crew is unable to fight or no longer present.

Another example is an Astartes Drop Pod, which uses its limited artificial intelligence to handle course corrections and to avoid collisions into dangerous terrain or anti-aircraft fire. Upon landing, it reroutes all logic processing into target acquisition and shooting for any on-board weapons.

Imperial Titans have particularly complex Machine Spirits and can exhibit complete personalities of their own, though they still require a cybernetic interface with the mind of a Human princeps of the Collegia Titanica to function at their full potential.

The Tech-priests of the Adeptus Mechanicus believe that these Machine Spirits can be influenced by religious rituals and are near-bestial in nature, capable of exhibiting emotions such as hatred and stubbornness. In particular, the Machine Spirits of Titans and Knights are revered for their particular intensity and require elaborate awakening and taming rituals.

With the use of brain-machine interface devices such as the MIU and the Throne Mechanicum, pilots of these war engines can link their minds with such a limited artificially intelligent Machine Spirit directly.



  • Warhammer 40,000: Rulebook (4th Edition), pg. 25
  • Warhammer 40,000: Rulebook (5th Edition), pg. 81
  • Adeptus Titanicus: The Horus Heresy Rulebook (Specialty game), pp. 93-97
  • Codex: Imperial Knights (7th Edition) (Digital Edition), "The Throne Mechanicum"
  • Codex Adeptus Mechanicus - Cult Mechanicus (7th Edition) (Digital Edition), "The Cult Mechanicus"
  • Imperial Armour Volume Seven - The Siege of Vraks - Part Three, pg. 161
  • Machine Spirit (Short Story) by Nick Kyme
Raven Rock Videos
Warhammer 40,000 Overview Grim Dark Lore Teaser TrailerPart 1: ExodusPart 2: The Golden AgePart 3: Old NightPart 4: Rise of the EmperorPart 5: UnityPart 6: Lords of MarsPart 7: The Machine GodPart 8: ImperiumPart 9: The Fall of the AeldariPart 10: Gods and DaemonsPart 11: Great Crusade BeginsPart 12: The Son of StrifePart 13: Lost and FoundPart 14: A Thousand SonsPart 15: Bearer of the WordPart 16: The Perfect CityPart 17: Triumph at UllanorPart 18: Return to TerraPart 19: Council of NikaeaPart 20: Serpent in the GardenPart 21: Horus FallingPart 22: TraitorsPart 23: Folly of MagnusPart 24: Dark GambitsPart 25: HeresyPart 26: Flight of the EisensteinPart 27: MassacrePart 28: Requiem for a DreamPart 29: The SiegePart 30: Imperium InvictusPart 31: The Age of RebirthPart 32: The Rise of AbaddonPart 33: Saints and BeastsPart 34: InterregnumPart 35: Age of ApostasyPart 36: The Great DevourerPart 37: The Time of EndingPart 38: The 13th Black CrusadePart 39: ResurrectionPart 40: Indomitus