Witches are long tradition in my homebrew. 'Witch' is a catch all term for 'any magic using being that makes me uncomfortable'. Depending on the culture, this can cover a very wide range, or it can be as narrow as using spells with the 'evil' descriptor. Just understand that often as not, the initial judge of whether something is witchcraft isn't necessarily an expert in the field.
Heretics are a similar story. Herasy is a catch all term for 'any teaching about the gods that makes me uncomfortable'. Depending on the culture, this can also cover a very wide range. Most nations have state religions consisting of a narrow approved pantheon. Anything outside of that is technically suspect, though in most countries this is honored more in the breach than in practice and 'folk religion' is winked at or informally folded into the official pantheon provided the practicioners except the subserviance of thier deities to the official ones and don't let it get in the way.
The following is from a homebrew document describing religion:
Atheism: Atheism is simply unknown in the Crimson Realms. There is simply overwhelming evidence of the reality of the gods. If anyone were to argue that the gods do not exist, and that all of the events that occur in the world are the product of some other force, then he would be considered insane and would be locked up for that reason rather than the feeling that he was teaching a dangerous philosophy.
Gantroism: The premise of the Gantroism heresy is that the gods are not especially worthy of worship. Gantroists believe that the gods are beings much like mortals, possessing greater power true, but even the best of them is capable of error and wrong. Therefore, the reasoning goes, the gods should no more be worshiped than great men, and should be deferred to for the same reasons that mortals are deferred to and no more than mortals are deferred to. The gods have no right to rule mortals' actions, and if they wish worship from individuals, they should strike a bargain with individual mortals.
The first sage to formally postulate the philosophy was Gantro of Corval, who lent it its now common name, but its most famous proponent was Acrocos of Sarman. Some followers of the belief system have been known to distinguish themselves as Acrocosians. There are a variety of other scholars of note who have wrote texts on the subject, and the philosophy has had repeated revivals in disparate regions of the Realms. Some of these writers appear to have arrived at their conclusion independently of Gantro's writings, and the exact teachings of the writers may vary greatly. Some are considered more offensive than others are.
In most of its forms, this is considered one of the lesser heresies. Its followers are not organized, though they do tend to seek out each other's company when they can find it. They tend to be moderate, passive, and intellectual - although some few do try to actively spread their beliefs. Most religions simply consider the philosophy foolish, and scorn its practitioners as guilty of hubris. Secular authorities seldom go further than banning the texts of famous proponents of the theory, and only the most famous and most charismatic followers of the philosophy have ever been executed under the law. Persecution of the heretics is generally left in the hands of whatever deity decides to become offended by the hubris. Such divine persecution is not infrequent, but is generally seen by the Gantroists as proof of the correctness of their philosophy, and the victims of any divine wrath are held up as heroes and martyrs by Gantroists. What persecution that does occur usually occurs at the hands of a mob that does not distinguish the less radical forms of Gantroism from Kelternism.
Kelternism: A radical offshoot of the Gantroism heresy attributed to Keltern the Leper, Kelternism proposes that mortals would be better off if gods did not interfere in their lives at all. It is perhaps the most famous heresy and probably the only one that the average unlearned person has heard of (and certainly the only one such a person would know by its formal name). It proposes that gods treat mortals much like toys, tools, or baubles to be used and played with and that whatever blessings they bestow are not worth the loss of free will they represent and the curses that they bestow with equal pleasure.
Although there are no doubt moderate and passive Kelternists, they tend to keep very quiet about their beliefs because, in the minds of most denizens of the Crimson Realms, Kelternism is invariably associated with Kelternist cultists. Kelternist cultist are highly radical followers of Keltern - perhaps even more radical than Keltern intended - who believe that the best way to obtain the utopian dream of a godless world is to destroy religion and ultimately memory of the gods. They tend to be violent and frequently attack and destroy religious buildings and clerics where ever they find them. As a result, they tend to live quite brief lives. Kelternism is punishable by death in most parts of the Crimson Realms and is illegal in theory everywhere. Writings by Keltern are banned everywhere, and simply owning one is grounds for execution in most municipalities.
Interestingly, some philosophers have concluded that it is likely - whether or not his spirit is currently being tormented by the gods - that Keltern has himself because of his veneration become something of a god himself. However, if this is the case, Keltern has remained true to his principles and has never been known to assist his followers in anyway.
Zhanism: The system of belief expounded by Zhan of Climostra proposes that gods are the creation of mortals, rather than mortals being the creation of the gods as is generally taught. This is of course a radical offshoot of the Existialist theory.
Although Zhanian writings (especially the original works of Zahn) do not necessarily promote anarchy or even impiety (Zhan himself seems to have held the gods in great reverence despite his theories on their origins), in the common mind Zhanians are considered not much better than Kelternists. This is probably do the fact that most Kelternists are also Zhanians, and is therefore assumed wrongly that most Zhanians are Kelternists. Zhanians do not help there own reputation by tending to be very strange. Zhanians are known to encourage the practice the worship of invented deities in hopes of creating new ones. They are known to distribute rewritten stories and religious works about deities whose principles they disagree with the hope of altering the nature of the deity. All of this tends to make it quite illegal to publicly express Zhanian sympathies anywhere with the probable punishment being death most everywhere.
Zhanism is probably unique among the heresies in drawing followers from a wide diversity of ethical and moral systems.
Monoism: A philosophy that believes that there is a single underlying principle to all things, rather than the dualist philosophy widely understood to be correct throughout the realms. Monoists tend to be the brunt of jokes and are considered stupid rather than dangerous in most cases. Monoist teachers are stereotyped as high-minded intellectual sophists whose philosophy is owed to their removal from the every day world. In short, monoists are thought to have no "common sense".
To a certain extent, this reputation is earned. Monoism is most common among sages and is debated generally in language that is so technical as to be incomprehensible to all but specialists in the field. A great many sages that debate monoism are not monoists themselves, and some sages even go so far as to suggest that the study of the great monoist works is essential to developing a full understanding of ethics and theology. The most widely respected monoist writer was Beren of Altair, but the single most famous monoist is without a doubt Verdan the Seer. There are very few monoist cults, but its followers are widely but sparsely spread throughout the realms.
Monoism is tolerated to a certain degree legally compared to other heresies, but teaching it publicly is likely to earn a term in the pillory or stocks. Execution is for the heresy of monoism is rare outside of all but the most lawful minded or most fanatical societies. On the other hand, monoists must endure a great deal of unofficial persecution and even the occasional lynching with little expectation of protection from authorities. Owning a monoist book is not generally illegal but will earn the owner a bad reputation.
Monoism is probably unique among the heresies in that the majority of its followers are lawfully aligned.
In some very neutral regions, a cleric that too strongly emphasizes his own deity over others may be accused of monoism.
Monotheism: Monotheism is extremely rare in the Crimson Realms. While it is not at all unusual for a person to believe or a cleric to teach that one deity is the most worthy of worship, it is extremely rare for a person to believe or teach that only one deity is worthy or worship - much less that only one deity exists. For one thing, the majority of deities represent powers or philosophies that are to narrow to be considered broad powers governing the world. For another, few if any clerics teach that their particular deity is all powerful or even supremely powerful. Finally, it is difficult to argue that a particular deity has a monopoly on virtue.
Nonetheless, despite the difficulty of all these arguments, there are small numbers of people who make one or more of them, and even a few books have been written on the subject. There are several 'All-Father' or 'All-Mother' cults in the Crimson Realms with various philosophies. The most common believes that all the gods are avatars of the single original creator - a sort of monoism. Another, an offshoot of Gantroism, holds that only the original creator is worthy of worship. In addition to these heresies, all the 'All-Father' cults are associated with a certain sort of hubris - that man thinks himself worthy enough to worship The Creator. No 'All-Father' cult has ever been able to manifest legitimate miracles and has a true clergy with divine power. This is attributed, at least by the cultists themselves, to the fact that the true name of the creator is not known. Quite a few individuals claim to have discovered the secret name of The Creator, only later to be discredited as charlatans or madmen. Many 'All-Father' cults are associated with Kelternists, and even those that aren't are seen as being associated with them. Although no secular power would be so audacious as to explicitly forbid the worship of The Creator, it is generally more than possible to find grounds to execute a member of an 'All Father' cult on some other charge of heresy.
The Creator is not the only power that is seen as being singularly worthy of worship by some. The Nameless Destroyer has a few cults of his own, who are similarly inefficacious in their power and whose only shared trait other than complete evil seems to be the ability to destroy themselves with dazzling alacrity. Although less attractive as a solitary principal because they are generally believed to have been created, the Cascade and the Tree of Life have also been the occasional objects of the worship of monotheistic cults. Quite a few cults have been started claiming that one particular deity, usually one not widely known, is the sole deity worthy of worship for one reason or another - usually because of his or her supposedly singular concern for mortals.
In addition to prohibited philosophies, it is generally illegal in all but the most chaotic parts of the Realms to defame or slander the local gods, or to attempt to usurp the worship of a traditional deity in favor of another one. Exactly what action constitutes a crime varies widely from place to place though. In Lystra, simply saying 'Gods be cursed’ is enough to land one in jail. In others, defamation will generally be overlooked unless a public speech deriding a specific popular deity is made or a story is related that is intended to make the deity show the deity acting out of character or wrongly. In others, what is officially illegal is overlooked and even smiled at.
Attempting to usurp the worship of a traditional deity is generally considered an even greater crime - probably because it represents such a direct threat to the power of the local clergy. Again, in some locales this law can be invoked for something as simple as openly worshiping a foreign deity or openly displaying a holy symbol of an unknown god. In others, you'd literally have to knock down altar statuary and replace it with something else before anyone would take interest. Even then some would probably suggest that the fact that the person got away with doing this is proof that a change of deities is in order, and that therefore at worst the criminal is guilty of vandalism. Most commonly this law is invoked in lawful nations whenever a cleric openly teaches about a proscribed deity. Chaotic nations generally either don't care or leave the 'trouble maker' to the will of the mob.
Finally, all lawful churches and most other churches to some degree or another have some body of teachings which is considered orthodox and canonical. Teaching something contrary to this body of beliefs is generally considered heresy by that particular church. This can mean trouble for a priest of that particular religion if the church is organized enough to keep tabs on its members, and trouble for anyone if the church has secular power in the country in which the person is teaching.
