Heresy - Definition of Heresy: The commission of heresy is often not merely the expression of an unconventional religious viewpoint, but the act of worshiping the Ruinous Powers of Chaos or aiding the forces of Chaos in attempting to subvert the rule of the Imperium.The worship of any god other than the Emperor is forbidden and those who overtly turn from the Imperial Creed are punished by death, as are those who deny the spiritual authority of the Adeptus Ministorum, the state church of the Imperium. While those men and women who turn to the worship of forbidden gods such as the Ruinous Powers or alien overlords are the most obvious of Heretics, many other variant belief systems have been declared heretical by the Ministorum or the High Lords of Terra throughout the ages.What does and does not count as heresy is generally determined by the high officers of the Ecclesiarchy. Massive divisions of the Adeptus Ministorum exist to monitor and study the myriad religious sects that exist across the Imperium and determine whether they have remained within the confines of the Imperial Cult's orthodoxy.The accusation of heresy is often used as a political weapon within the Imperium by those wishing to gain power over others. This can occur at multiple levels. A reasoned debate between brother cardinals can be brought to an immediate end should one of the two hint at accusing the other of heresy. An Imperial diocese that has proven tardy in the raising of tithes can be brought into line by the merest hint of the word.An accusation of heresy is a blunt tool, and one that can turn upon its wielder, for those accused might have previously unknown allies or political patrons, and outright war between rival factions sometimes results.There are several variant faiths within the Imperium which the Ecclesiarchy has no choice but to tolerate, even though it disagrees fundamentally with their tenets. The Chapter cults of the Adeptus Astartes are often such faiths, as is the machine-worship of the Adeptus Mechanicus.Every Space Marine Chapter is faithful to the Emperor and its own ancestral primarch, but they do not usually revere the Emperor as a god. Rather, to them He is but a man, albeit the greatest who has ever or will ever live. This breaks with the single most important tenet of the Imperial Creed, that the Emperor is divine, and has on many occasions proved a source of great tension and even overt hostility between the two Imperial adepta.On the whole, however, the Adeptus Ministorum and the Adeptus Astartes try to maintain cordial relations, for the Space Marines are the literal genetic descendants of the Emperor through the blood of the primarchs, which flows in their own veins ten thousand standard years after the entombment of the Master of Mankind in the Golden Throne.The Cult Mechanicus is another deviant faith with which the Ecclesiarchy is often at odds. The tech-priests of the Adeptus Mechanicus worship their own deity, who they call the Machine God. As with the Imperial Creed, many sects exist within the Cult Mechanicus, and it is commonly held that the Machine God is in fact a manifestation of the Emperor in His form as the Omnissiah, the physical avatar of the Machine God in the material universe, although many in the Ecclesiarchy have great difficulty accepting this.Other Mechanicus sects appear to outsiders to be saturated in idolatry, worshipping the very machines they are tasked with maintaining and committing a thousand other spiritual transgressions punishable by death by the laws of the Adeptus Ministorum and the Imperium. Despite such differences, the Ecclesiarchy has no choice but to tolerate the Cult Mechanicus, just as the Emperor during the Great Crusade had to ironically accept their deviance from the atheistic Imperial Truth, for without the tech-priests the Imperium would literally grind to a halt.No Imperial institution can do without the Adeptus Mechanicus, just as none forgo the services of the Adeptus Astra Telepathica or the Navigator Houses, regardless of how distasteful the faithful might find their psychic servants.The Ecclesiarchy is especially interested in those that not only reject the Emperor, but also embrace something else in His place. These slaves and servants to xenos and Warp entities are viewed as true Heretics and their discovery and eradication is a prime goal of the Ministorum throughout the Imperium. Finding such Heretics can, however, be a difficult task. Amidst the thousands of Imperial cults and saints, it is easy for seemingly faithful practises to mask heretical deeds.To a certain degree, the Ministorum polices its own ranks against this corruption, but it is an impossible task keeping tabs on a church that spans tens of thousands of light years and countless worlds. Even those who obviously seem to bear taint are not always guilty.Psykers and mutants, for instance, are two groups that often bear the suspicion of heresy, sometimes unfairly, sometimes not. While it would be convenient to brand all of these individuals as an affront to the Emperor and a scourge upon the Imperium, they are far too integrated into Imperial society to purge them wholesale.As a result, the Ministorum and other Imperial forces such as the Inquisition must rely on investigation and intelligence-gathering. Planets and their populations must be watched and monitored for signs of taint. Saints and cults must be screened and rumours of dark deeds investigated. No person is beyond the suspicion of the Inquisition, not even the great Space Marines of the Adeptus Astartes.Acts of heresy are categorised in legalistic grades (1st, 2nd, 3rd, etc.) which differ based on the severity of the act. Punishments range from imprisonment, assignment to an Astra Militarum Penal Legion, excommunication from the spiritual rites and protection of the Ecclesiarchy, execution, and arco-flagellation, to name but a few.