The vast majority of people live their entire lives without ever becoming aware of the God Machine. What mysteries humans do perceive are written off, left to be pondered by nutjobs and conspiracy theorists.
But for some, those encounters are not so easily dismissed. To them the God Machine becomes a harsh and clear reality. Be it through a feature of a Facility, a random anomaly, or even direct demonic interference, they are touched by the God Machine and forever changed.
The average stigmatic's first encounter with the God Machine comes by pure chance. Perhaps they stumble upon Infrastructure, find an object of angelic design, or witness a demon's true form. Others are pulled into the system deliberately, drawn to a God Machine cult or recruited directly by an angel. The Unchained are guilty of similar recruiting tactics, with spells that can forcefully open a human's eyes to the truth of the world around them.
The change begins within the first few hours of the encounter, and can take anywhere from mere minutes to several weeks to manifest entirely. It begins with hallucinations and changes in perception that cannot easily be explained. The experience is horrifying, akin to being trapped in a ceaseless dream where the familiar is made bizarre. Even if they could make sense of the visions, which for the most part they can’t, the burgeoning stigmatic is traumatized. As horrific as visions may be, however, the next stage is worse.
The stigmatic develops a brand, a physical tell that they have been touched by the God Machine. Brands vary. They leave frost on whatever they touch, develop glowing tattoos that move across their skin, their reflection vanishes entirely: these are but a small sample of possible phenomena. This process is often very painful, and if a stigmatic had any hope of returning to normal, that hope is now dashed. Even if those brands are minor and easily concealed, the change scars their psyche deeply.
With the manifestation of a brand, stigmatic visions recede and the world returns to focus, but it will never look the same again. Beings and Facilities that were previously hidden now stand obvious, and Infrastructure is laid bare. Worse, those elements now seek them out. The stigmatic will spend the rest of their life hiding from the God Machine.
More rare are those born as stigmatics, having been exposed to the Symphony prior to their birth, whether through angelic influence, parental demonic pacts, or ambient Infrastructure. Though some theorize that stigmatism can arise genetically, whether through mutation or inheritance, there's no concrete proof. Stigmatic lineages more than two or three generations are rare, and more often than not caused by an outside force.
In some sense, these stigmatics are lucky. They don't undergo the same change as those who come into their affliction later in life - or if they do, they simply don't remember it. Nor do they remember a time before their stigmatism, and in having no experience with a "mundane" world, there is often less grief by comparison.
Of course, growing up as a stigmatic is inherently traumatic, as children are even less equipped to handle the strain of a stigmatic life than adults. Worse than that, stigmatics born to mundane families suffer from a perpetual otherness, being able to see and sense things that others cannot.
In theory, any time a human encounters a part of the Symphony, they are at risk of becoming a stigmatic. This is not guaranteed - otherwise, there would be a lot more stigmatics running around, given the sheer prevalence of the God Machine's projects and the need for demons to leverage mortals using their supernatural abilities. And yet, stigmatics remain a minority in the human population, for more than just their high-mortality rate.
In fact, the majority of humans are able to resist stigmatism, instead writing off encounters with the God Machine as something more palatable to the human mind (perhaps with the aid of an angel, if the God Machine deems it necessary). Of course natural susceptibility varies, and a person only needs to be unlucky once for their life to be forever changed. Theories claim that particularly weak-of-mind humans are more likely to be changed by the Symphony, though conspiracy speaks of more subtle, less easily traced vulnerabilities. If it were as easy as simply repeatedly casting spells or transforming around humans, the Unchained would not invest in spells like Stigmatic Vision (and perhaps some would be far more cautious about their abilities... or far more reckless).
Some mechanics already exist for turning a human into a stigmatic, such as through Stigmatic Vision or human use of gadgets. Other times, a Storyteller may inflict stigmatism as they see fit for their narrative. But how should accidental stigmatism be played out mechanically in a general case? A Storyteller with a human NPC or players with a mortal PC may find it interesting to see how long they hold out until they become a stigmatic.
Consider using the following system: whenever a human witnesses a supernatural phenomenon caused by the Symphony, roll a Breaking Point (with any fitting modifiers by Integrity and the particulars of the situation). On a Dramatic Failure, they become a stigmatic. Think about applying additional penalties (or even bonuses) for repeated exposure to the Symphony, or what angelic or demonic influences that may chance how susceptible an individual is. As this system is optional, be sure to discuss with players of mortal PCs beforehand.
Though the factors that lead to the creation of a stigmatic are generally well understood, demons have also found that some humans simply resist becoming a stigmatic at all. By popular knowledge, no mundane is truly immune without some kind of other influence - the protection of an angel or demon, for example, can interfere with the transformation. Most commonly, an active wish pact grants the pactholder temporary immunity to stigmatism, lifted when their demon departs. A human might be particularly resistant, but enough force applied will always cause a breakage.
So why is it that some otherwise completely ordinary humans are unaffected by their encounters with the God Machine? Many demons argue that such mortals don't exist - their breaking points simply haven't been reached yet. Testing this, of course, is unethical at best, and bound to draw attention at worst. Others subscribe to conspiracy - that humans may one day develop some kind of persistent immunity to the eldritch effects of the Symphony. Some think that's a good thing - it means fewer traumatized casualties, in the end. Others fear that it may be a plot of the God Machine to reduce what tools the Unchained have at their disposal. Perhaps It has calculated that such a shift in humanity would ultimately benefit It in the long run, even if It deprives Itself of tools as well.
Of course, that's assuming there's any truth to such rumors at all.
Being stigmatic is a miserable experience. The visions a stigmatic endure drive home just how small and helpless they are. Some stigmatics are fortunate (or unfortunate) enough to develop other supernatural powers beyond their ability to see into the system, but even then these powers merely serve to draw the attention of angelic forces.
What's more, though stigmatics can now view the systems of reality, and the human mind is in no way designed to make sense of the enormous information overload. Visions which could be critical portents appear as little more than gibberish, more distracting than they are helpful. New stigmatics are rarely equipped with the occult experiences necessary to even begin interpreting their visions.
Stigmatics who aren’t completely overcome by their new perceptions are still lost in an alien world with little direction. They don't suddenly know what they are or the context of the truths they're now privy to. The veil has been pulled back, but without guidance, they many never even learn the term stigmatic. Many often become obsessed with the study or evasion of the event, being, or object that caused their transformation. A stigmatic may do their best to return to life as if nothing changed, but soon discovers that even if they want nothing to do with the God Machine, it takes a keen interest in them. The high mortality rate of stigmatics can be attributed to a mix of suicide, the dangers of seeking out the supernatural, and those who seek to use them for their own ends.
Angels seek out stigmatics as relentlessly as they do the Unchained, but not as malignantly. Just because a person has become stigmatic does not mean they are automatically on the God Machine’s hit list. Certainly, if they repeatedly oppose the God Machine and endangers Infrastructure, a stigmatic will find themself in an early grave, but if they keep their head low and don’t cause problems, the God Machine won't waste resources on removing them.
The God Machine won’t ignore them, however. Stigmatics are useful to the God Machine as cult members, test subjects, and bait for demons. There will always be a pale man watching from the corner table, ciphers in the mailbox, and late night visitations — if not from angels, then from demons looking for tools of their own.
How the Unchained approach stigmatics is very much dependent on their Agendas. Inquisitors see stigmatics as potential sources for information, being more closely tied to the God Machine’s machinations. Integrators look upon them as gateways to interaction with the system. Saboteurs see potential allies in their war or weak points to exploit. Tempters judge each stigmatic individually, examining her closely to determine how they can get the greatest benefit.
No matter how a demon approaches a stigmatic, they are always taking a risk. Not all stigmatics are on the run from the God Machine; some serve it, and those who don’t might still be working for a rival Agency. Those who have recently encountered the God Machine will have little knowledge of the Unchained or their cause and are unlikely to willingly ally themselves with "monsters".
Still, stigmatics allies often play a variety of critical roles for Rings and Agencies. They are valuable contacts and lookouts, provide cover stories when a demon's identity is in jeopardy, and act as the cavalry when a cover story fails. A stigmatic's ability to perceive Infrastructure makes him invaluable as a scout. Some are even powerful psychics, capable of obvious feats of power too risky for a demon’s Cover.
Of course, this doesn't mean demons view stigmatics as their equals. Stigmatics can earn the respect and even admiration of the Unchained, but even so, few would choose one of their "lesser cousins" as backup when walking into a Facility. A stigmatic may gain some notice in an Agency but still find themself barred from joining a ring simply because of their lesser paranormal capabilities, or because its members don't care to admit someone who is not Unchained. After all, a ring is an eminently practical, feet-on-the-ground organization. A mere human is unlikely to pull their weight.
For this reason, stigmatics who join a ring are decidedly above the norm. They have skills or resources that outweigh their potential liabilities. They know how to use their non-demonic nature to their advantage, walking into and out of a Facility without tripping the sensors a demon would. They use their understanding of humanity to gain the trust of an unwitting servant of a rival Agency where the Unchained would be hard-pressed to not raise some hackles. They use their stigmatic abilities to carve out advantages, pretending to be more than they are and making it work. Some of these stigmatics may have even joined a ring as an ordinary human and been transformed later - potentially against their will, and persuaded to see their new comrades' point of view.
Demons may talk a good game about accepting a stigmatic, but the truth is they are a breed apart from the Unchained. Just as stigmatics look at humanity with some envy and some contempt, the Unchained view stigmatics as dabblers. This contempt usually manifests in subtle ways, such as innocuous-seeming jokes about the human member’s lack of a demonic form, the other ringmembers talking about the ring as though it had only Unchained members, forgetting the stigmatic member when listing up those who belong to the ring, settling on a code language the non-demon doesn’t understand, and giving the human member their assignment as an afterthought. A stigmatic might come to resent their comrades-in-arms or fall into a pattern of desperately trying to prove their worth.
It’s also fairly easy to blame the ring for their new existence. For a stigmatic member, this sort of recrimination can grow very bitter with time. The occasional human ring member take pains to remind their fellows that they have no need to participate in the fight — the God Machine isn’t after them, so they can leave whenever they want. This, of course, is a misconception. Anyone who runs with the Unchained is an enemy of the Machine, and It is not a merciful god.
During their transformation, stigmatics gain an innate understanding of a few Etudes or Cadenzas, as the harrowing visions grant them a brief but nigh-incomprehensible insight into reality. The spells they gain come in two forms: those that directly reflect who they are as a person and how they interact with the world, and those that they pick up on from the metaphysical brushing-of-shoulders with their maker. They are rarely aware of their new powers until told, though many stumble into casting spells, especially those of the personal reflection variety - after all, with Etudes especially, a spell is merely a new approach to an old problem. Meanwhile, those who gain spells familiar to their maker are more likely to also develop hints of a demonic form - though this is still very, very rare.
Stigmatics can learn more spells as they settle into their new lives, and those who work under angels may even have them directly implanted. Unlike demons, they lack the memories of angelhood to reverse-engineer Etudes and Cadenzas from, meaning they are unable to learn spells on their own. However, now being a human warped by the Symphony, they find it easier to learn by observation. Stigmatics can quickly pick up a few new tricks of their own by watching someone else cast a spell... or by having spells cast on them.
Unlike pactholders, stigmatics do not risk Magic Overflow nor Compromise when using their spells. Having been fundamentally altered on an existential level, a stigmatic's supernatural abilities are innate to them. They can't overload their soul with the Symphony when it's built into them, and reality accepts their existence enough that they do not trigger a response from the God Machine in the same way pactholders and Unchained do. Of course, angels and other God Machine agents may investigate if they see a stigmatic acting unnaturally, and may choose to pursue them should the need arise. Additionally, stigmatics do not trigger aetheric resonance even when they spend Aether, but do trigger acoustic resonance.
Stigmatic pactholders follow mechanics for Magic Overflow, Compromise, and aetheric resonance like any other pactholder, due to their abilities now coming from an external source - a demon.
Stigmatics operate under the Exposure mechanics rather than Compromise. The idea of Compromise is directly linked to demons and their Cover (and pactholders, whether they like it or not, are a type of Cover). Stigmatics are thoroughly human, even though they've been touched by the God Machine, and thus straddle a line between reality and Symphony without the use of Cover.
A stigmatic should check for Exposure when:
using a spell would normally cause Compromise, such as any Cadenza or certain Etudes like Read Score
acting in a manner that reveals their supernatural senses, such as using Stigmatic Sense or visibly reacting to Infrastructure
When checking for Exposure, roll Wits + Manipulation. Apply modifiers based on the Symphonic density and danger of an area, such as a -3 if they're surrounded by Infrastructure, or a +2 if they're among potential allies.
Note that Exposure rolls do not benefit from Interference - Exposure is not so much checking if the stigmatic has 'pinged' the God Machine's sensors, as much as it is testing the probability of being noticed by someone in the area.
On failure, the Storyteller can enact complications. Perhaps a demon becomes curious, or an angel keeps watch. Storytellers can choose choose to play out complications at their discretion, such as requiring multiple failed Exposures, or having them escalate in severity with each successive failed Exposure.
Every stigmatic sees the God Machine and Its workings differently. A vision may come to one stigmatic and not another. Information may differ between two visions. Perhaps one focuses on bloodshed that will occur at a location, while another notes the exact phase and position of the moon overhead. Even if two stigmatics happened to learn of the same omen, their visions would come about differently.
Stigmatic visions always affect sight, though can extend to all senses, depending on circumstances and individual. A stigmatic's visions almost always reflects the aesthetics of the event - or individual - that caused their stigmatism. A vision might be heralded by winter chills and frost creeping up windows, or always feature the sound of church bells tolling overhead.
Unfortunately, not all visions are actually useful. In fact, most are ultimately meaningless. Perhaps the information contained within is too vague or watered down to be useful, or not of a relevant time period. Stigmatics find themselves haunted by the echoes of their traumatic transformation at unpredictable moments, with little benefit. Even worse, but the distracting visions only make it more difficult to tell when a vision is actually important.