The Inquisition — Warhammer 40k Secret Police

Impact on the Setting

The concept of The Inquisition is one of the foundational pillars upon which the Warhammer universe is constructed. Its influence extends across every faction, every conflict, and every narrative thread that Games Workshop has woven into their sprawling setting. Without The Inquisition, the dynamics of power, faith, and survival that define the grimdark future would be fundamentally different.

At the strategic level, The Inquisition shapes the decisions of the Imperium’s highest authorities, from the High Lords of Terra to the Chapter Masters of the Adeptus Astartes. Military campaigns are planned around its implications, diplomatic relationships are forged or broken by its influence, and entire civilisations rise and fall according to its dictates. The Imperium’s relationship with The Inquisition is paradoxical — simultaneously dependent upon it and terrified by its consequences.

For the enemies of humanity, The Inquisition represents both opportunity and threat. The forces of Chaos seek to exploit or corrupt it, the xenos races respond to it according to their own alien philosophies, and those caught between the great powers must navigate its effects with whatever resources they can muster. This multifaceted impact ensures that The Inquisition remains relevant across every theatre of war and every era of the setting’s timeline.

The narrative weight of The Inquisition has only grown as Games Workshop has advanced the setting’s timeline beyond the 41st Millennium and into the Era Indomitus. New developments have added layers of complexity to a concept that already carried enormous significance, ensuring that it will continue to drive stories and conflicts for years to come. Scholars, strategists, and mystics across the galaxy continue to debate its true nature and ultimate implications, and none can claim to fully understand it.

In-Game Representation

On the tabletop, The Inquisition manifests through a variety of rules mechanics that attempt to capture its narrative significance in gameplay terms. Games Workshop has approached this challenge differently across editions, sometimes representing it through army-wide special rules, sometimes through specific stratagems or abilities, and sometimes through the very structure of mission design.

In the current edition, players can see The Inquisition’s influence in detachment abilities, enhancement options, and strategic ploys that reflect its lore impact. Armies that are thematically connected to The Inquisition often receive unique rules that reward players for embracing the concept’s narrative implications on the battlefield. These mechanics create gameplay experiences that feel authentically tied to the setting, rewarding both competitive play and narrative storytelling in equal measure.

Deeper Lore

Beyond the well-known aspects of The Inquisition that appear in codexes and mainstream Black Library fiction, there exists a wealth of deeper lore that rewards dedicated researchers. Forge World publications, campaign supplements, and older editions of the game contain information that adds crucial context to our understanding of the concept.

One of the most fascinating lesser-known aspects of The Inquisition is its connection to the Age of Strife — the period of galactic catastrophe that preceded the Emperor’s unification of Terra. Records from this era, fragmentary and often contradictory, suggest that The Inquisition’s origins are far more ancient than commonly understood. Some radical Inquisitors have proposed theories linking it to xenos influence or even to the fundamental structure of reality itself, though such speculation is considered heretical by mainstream Imperial theology. The truth, buried under ten thousand years of dogma and propaganda, remains tantalisingly out of reach — a mystery that may never be fully resolved, but whose pursuit drives some of the setting’s most compelling narratives.

What Is the Inquisition?

The Inquisition is the most powerful and feared organisation in the Imperium of Man — a secretive body of extraordinary individuals known as Inquisitors who possess almost unlimited authority to investigate, judge, and execute anyone suspected of heresy, corruption, or betrayal. Answering only to the Emperor himself (who sits silent on the Golden Throne), the Inquisition operates above all other Imperial institutions, including the Space Marines, the Imperial Guard, and even the High Lords of Terra.

The Inquisition was founded in the aftermath of the Horus Heresy by Malcador the Sigillite, the Emperor’s closest advisor, who recognised that the Imperium needed a watchdog organisation that could act without bureaucratic constraints. The original Inquisitors were chosen from the most loyal and capable individuals Malcador could find — warriors, scholars, psykers, and diplomats who would dedicate their lives to protecting the Imperium from threats both external and internal.

Ten thousand years later, the Inquisition has grown into a vast, decentralised network of thousands of Inquisitors, each operating with tremendous autonomy. They maintain no standing army of their own but can requisition Imperial forces from any branch of the military, commandeer vessels from the Imperial Navy, and demand cooperation from any Imperial citizen or organisation. An Inquisitor’s authority is, in theory, absolute — challenged only by other Inquisitors.

The Three Major Ordos

The Inquisition is divided into numerous Ordos — specialised branches that focus on specific threats to the Imperium. While dozens of minor Ordos exist, three Major Ordos form the backbone of the Inquisition’s operations:

Ordo Hereticus — The Witch Hunters

The Ordo Hereticus hunts heretics, traitors, and unsanctioned psykers within the Imperium itself. These Inquisitors investigate cults, root out Chaos corruption in Imperial organisations, and monitor the Adeptus Ministorum (the Imperial Church) for signs of deviation from approved doctrine. The Adepta Sororitas (Sisters of Battle) serve as the Ordo Hereticus’s military arm, the Chamber Militant, providing zealous warriors who share the Ordo’s dedication to purging heresy.

Ordo Hereticus Inquisitors are feared even by other Imperial institutions because their investigations can target anyone — planetary governors, military officers, Ecclesiarchy priests, and even other Inquisitors. Their methods range from subtle infiltration and intelligence gathering to dramatic purges that can see entire populations put to the torch if heresy is deemed too widespread to contain.

The Ordo Hereticus walks a difficult line between necessary vigilance and destructive paranoia. Some Inquisitors of this Ordo are measured investigators who carefully build cases before acting. Others are zealots who see heresy everywhere and respond with overwhelming force, sometimes destroying loyal Imperial citizens alongside genuine traitors in their fervour to purge corruption.

Ordo Malleus — The Daemon Hunters

The Ordo Malleus specialises in combating the daemonic — entities from the warp that manifest in realspace to corrupt, destroy, and consume. These Inquisitors study daemonology, warp phenomena, and the nature of the Chaos Gods, using forbidden knowledge to fight an enemy that most Imperial citizens are not even permitted to know exists. The Grey Knights Space Marine Chapter serves as the Ordo Malleus’s Chamber Militant, providing the Imperium’s most specialised daemon-fighting warriors.

Ordo Malleus Inquisitors deal with threats that would drive ordinary humans insane. They investigate daemonic incursions, seal warp rifts, and hunt down individuals who have made pacts with daemons. Their work frequently requires knowledge that is itself considered heretical — understanding how daemons function, knowing the true names of daemonic entities, and studying the mechanisms by which the warp interacts with reality.

This creates a philosophical tension within the Ordo Malleus. Some Inquisitors believe that knowledge of the daemonic is necessary to fight it effectively, advocating for the study and even controlled use of warp-related artefacts and knowledge. Others insist that any contact with the daemonic is inherently corrupting and that the only appropriate response to daemonic threats is immediate and total destruction. This fundamental disagreement has led to conflicts within the Ordo that occasionally escalate to open warfare between rival Inquisitors.

Ordo Xenos — The Alien Hunters

The Ordo Xenos focuses on threats from alien civilisations. These Inquisitors study xenos biology, technology, and culture, seeking to understand alien species well enough to counter them effectively. They monitor alien incursions into Imperial space, investigate reports of xenos influence on human worlds, and develop strategies for combating specific alien threats. The Deathwatch Space Marine Chapter serves as the Ordo Xenos’s Chamber Militant, fielding kill-teams of specially-selected Space Marines drawn from multiple chapters.

The Ordo Xenos deals with an enormous range of threats, from the galaxy-consuming Tyranid Hive Fleets to the technologically advanced T’au Empire to the ancient and inscrutable Aeldari. Each alien species requires different approaches, and Ordo Xenos Inquisitors often specialise in a particular race, becoming experts whose knowledge is invaluable when that species threatens Imperial interests.

Like the other Ordos, the Ordo Xenos contains a spectrum of philosophical positions. Radical Inquisitors may advocate for temporary alliances with certain alien species against greater threats, or even use xenos technology to augment Imperial capabilities. Puritan Inquisitors maintain that all aliens are enemies of humanity and that any cooperation with xenos species is a betrayal of the Emperor’s vision for a human-dominated galaxy.

Inquisitorial Powers and Authority

An Inquisitor’s authority is derived from the Inquisitorial Seal — the rosette — which serves as both identification and a symbol of absolute power. An Inquisitor bearing the rosette can commandeer any Imperial resource, override any Imperial authority (except another Inquisitor of equal or greater standing), and pass judgement on any Imperial citizen, from the lowest hive worker to the most powerful planetary governor.

This authority extends to several specific powers that make Inquisitors among the most dangerous individuals in the Imperium:

Exterminatus: The most extreme power an Inquisitor can invoke. Exterminatus is the complete destruction of a planet’s biosphere — typically through virus bombs, cyclonic torpedoes, or sustained orbital bombardment. This power is reserved for situations where a planet is deemed so thoroughly corrupted that no other remedy is possible. While any Inquisitor theoretically has the authority to declare Exterminatus, doing so without overwhelming justification can lead to censure from other Inquisitors.

Requisition: An Inquisitor can requisition forces from any branch of the Imperial military, including Space Marine chapters (though chapters may resist such demands). This allows a single Inquisitor to assemble a formidable military force from whatever Imperial assets are available in the region, creating bespoke armies tailored to specific missions.

Judgement: An Inquisitor serves as investigator, prosecutor, judge, and executioner. There is no appeal from an Inquisitor’s judgement, and their sentences can range from exoneration to execution to mind-wiping to planetary destruction. This concentration of power is deliberate — the Inquisition’s founders believed that the threats facing the Imperium were too urgent and too dangerous for normal judicial processes.

The Inquisitor’s Retinue

Inquisitors rarely operate alone. Each typically maintains a retinue of specialists, warriors, and agents who assist with investigations and provide combat support. These retinues are as varied as the Inquisitors who assemble them, reflecting each Inquisitor’s methods, specialisation, and personality.

Common retinue members include: Acolytes — Inquisitors-in-training who handle routine investigation and serve as assistants; Interrogators — senior acolytes being evaluated for elevation to full Inquisitor status; Crusaders — dedicated warriors who serve as bodyguards; Mystics — sanctioned psykers who provide psychic support; Savants — scholars and data-analysts who process information; and Death Cult Assassins — fanatical killers devoted to the Emperor through obscure religious cults.

Some Inquisitors maintain large retinues numbering in the dozens, effectively commanding small private armies. Others prefer to work with only a handful of trusted operatives, relying on subtlety rather than force. The most powerful Inquisitors can call upon entire networks of agents spread across multiple sectors, creating intelligence-gathering operations that rival those of planetary governments.

Famous Inquisitors

The Inquisition’s history is filled with legendary figures whose actions have shaped the Imperium:

Eisenhorn: Perhaps the most famous Inquisitor in Warhammer 40,000 fiction, Gregor Eisenhorn is an Ordo Xenos Inquisitor whose career spans centuries and demonstrates the Inquisition’s central philosophical conflict. Beginning as a firm Puritan who adhered strictly to Imperial doctrine, Eisenhorn gradually adopted more Radical methods as he confronted increasingly dangerous threats, eventually using the very tools of the enemy to fight against them. His story, told through Dan Abnett’s acclaimed novel series, explores the question of how far a good person can go in fighting evil before becoming evil themselves.

Ravenor: Gideon Ravenor was Eisenhorn’s most talented student, an Inquisitor of exceptional psychic ability who was crippled in a daemon attack and continues his work from within a force chair — a levitating life-support system equipped with weapons and psychic amplifiers. Ravenor’s story continues the themes of Eisenhorn’s but from the perspective of a younger generation of Inquisitors.

Karamazov: Lord Inquisitor Fyodor Karamazov is the embodiment of Puritan extremism. Riding a massive walking throne armed with multi-meltas, Karamazov travels the Imperium dispensing harsh judgement with zero tolerance for anything he deems heretical. He represents the Inquisition at its most uncompromising — effective against genuine threats but terrifying to loyal citizens caught in his path.

Coteaz: Inquisitor Lord Torquemada Coteaz is one of the highest-ranking members of the Ordo Malleus and a legendary daemon hunter. Unlike many Inquisitors who operate in secrecy, Coteaz is a public figure who leads from the front, personally fighting daemons alongside Grey Knights and inspiring terror in the enemies of the Imperium through his reputation and presence.

Puritans vs Radicals

The Inquisition’s greatest internal conflict is the philosophical divide between Puritans and Radicals — two opposing schools of thought on how best to protect the Imperium:

Puritans believe that the Imperium’s strength lies in strict adherence to Imperial doctrine and the total rejection of heretical tools, alien technology, and warp-derived power. They view any compromise with the enemies of humanity as the first step toward corruption and damnation. Puritan Inquisitors destroy Chaos artefacts rather than study them, refuse to deal with aliens under any circumstances, and judge harshly anyone who deviates from approved Imperial behaviour.

Radicals believe that the threats facing the Imperium are too severe and too varied to be combated with orthodox methods alone. They advocate for using every available tool — including forbidden knowledge, xenos technology, and even daemonic artefacts — to protect humanity. Radical Inquisitors argue that refusing to use effective weapons against existential threats is not purity but suicidal stubbornness.

The conflict between Puritans and Radicals is not merely academic. Inquisitors have fought and killed each other over these philosophical differences, and the Inquisition’s history includes numerous internal wars where factions have clashed over methodology. Neither side is entirely wrong — Puritans correctly identify that Radical methods carry genuine risks of corruption, while Radicals correctly point out that Puritan rigidity sometimes prevents effective responses to existential threats.

The Inquisition on the Tabletop

In Warhammer 40,000, Inquisitors can be fielded as part of an Imperial Agents force or allied into other Imperial armies. They provide unique capabilities including psychic powers, special abilities that affect enemy army composition or deployment, and the ability to bring specialised retinue members that fill gaps in your army’s capabilities.

Inquisitors are typically inexpensive HQ choices that provide utility rather than raw combat power. Their value lies in their special rules, which can disrupt enemy strategies, buff nearby Imperial units, or provide information about enemy forces. They work well as support characters attached to Astra Militarum or Sisters of Battle forces, where their abilities complement the army’s existing strengths.

Frequently Asked Questions

How powerful is an Inquisitor compared to a Space Marine?

In raw combat ability, most Inquisitors are inferior to Space Marines — they are still baseline humans (though often augmented with bionics, psychic powers, and rare wargear). However, their political authority far exceeds any Space Marine’s. An Inquisitor can theoretically command a Space Marine chapter to comply with their orders, though most chapters would resist such demands.

Can an Inquisitor really destroy a planet?

Yes. The power of Exterminatus allows an Inquisitor to order the complete destruction of a planet’s biosphere. This extreme measure is reserved for situations where a world is deemed beyond saving — typically due to widespread daemonic corruption or uncontrollable xenos infestation. While any Inquisitor can theoretically invoke this power, doing so without clear justification risks censure from other Inquisitors.

What are the three main Ordos of the Inquisition?

The three Major Ordos are: Ordo Hereticus (witch hunters who investigate internal heresy), Ordo Malleus (daemon hunters who combat warp entities), and Ordo Xenos (alien hunters who counter xenos threats). Each has a Space Marine chamber militant: Sisters of Battle, Grey Knights, and Deathwatch respectively.

Who founded the Inquisition?

The Inquisition was founded by Malcador the Sigillite, the Emperor’s closest advisor, in the aftermath of the Horus Heresy. Malcador selected the original Inquisitors from the most loyal and capable individuals he could find, giving them broad authority to protect the Imperium from threats that conventional military and political structures could not address.

What is the difference between a Puritan and a Radical Inquisitor?

Puritans adhere strictly to Imperial doctrine and reject the use of heretical tools, alien technology, or warp-derived power. Radicals believe that extreme threats justify extreme methods, including the use of forbidden knowledge and enemy weapons. The conflict between these philosophies is the Inquisition’s greatest internal divide.

Can Inquisitors be corrupted by Chaos?

Yes. Despite their training and willpower, Inquisitors can fall to Chaos corruption — especially Radicals who work with dangerous warp artefacts or forbidden knowledge. The Inquisition monitors its own members for signs of corruption, and corrupted Inquisitors are hunted by their former colleagues with particular urgency, as a fallen Inquisitor with their knowledge and authority represents an extreme threat to the Imperium.

The Inquisition — Warhammer 40k Secret Police