Magic is by its nature transgressive: it breaks the laws of nature or evokes power best left untouched. When a Sorcerer attempts magic beyond their ability or purposely seeks out that knowledge, the magic they wield corrupts their nature and attunes the Sorcerer more closely with whatever dark nature magic has.

The source of this magic can be alien or otherworldly, demonic, a touch of the fey or drake in one’s blood, the cold uncaring unknown, the chilling wind of the undeath, or the pureness of chaos. Once the power has been awakened within, once one has had a taste of power greater than their own, once demons have whispered into their ears or the limitless vistas of an ever-shifting reality of our own, one can tap into that power to enhance their own magic.

The GM should determine where the magic comes from and how this power can be corrupting.

Acquiring Corruption

The first time a Sorcerer casts a spell where they fail to invoke the spell but do gain a set beneath the Intensity of the spell, they have glimpsed or summoned power beyond their own and their spell falters. They gain their first Corruption Point. If they so choose, they can then immediately use that die and roll it if they so desire to see if they can make any sets.

Using Corruption

The Sorcerer now has avenue to a forbidden source of power which they can use to power their invocations. Whenever a Sorcerer casts a spell, they can choose to allocate any number of dice as a bonus to the roll before the dice are rolled. These bonus dice should be in a different color or rolled into a different pool. These dice can then be used to create sets. If a Sorcerer has at least three Corruption, they can replace three dice with an Expert die, although there are consequences as noted below.

Based upon the exact nature of Corruption that the player has acquired, Corruption might also be applicable as bonus dice to certain other actions, as determined by the GM. These could be used as bonus die/dice for certain skills. If the Corruption dice used for this fail to form a set, they do not increase Corruption but create a complication to the current scene or to a latter scene directly resulting from the character’s misuse of their power.

Increasing Corruption

Whenever a Sorcerer commits Corruption dice to a roll and none of the dice create a set that matches or exceeds the Intensity of that spell, Corruption increases by one. Typically, Corruption dice must be committed before the roll, but as soon as one’s corruption increases as a result of gaining Initial Corruption or Increased Corruption from Corruption dice failing to form any successful sets, the die resulting from the increase can then be rolled and added to the set. If this new additional die from the increase in Corruption does not form any sets, it does not trigger an increase in Corruption. An Expert Die used in a spell always triggers an increase in Corruption.

Alternative Means of Increasing Corruption

There may be other ways to increase Corruption besides failing at spells while evoking corrupting power. What may increase Corruption depends on what Corruption represents: a human sacrifice to demons may increase Corruption for one Sorcerer, while turning one’s firstborn over to the Fey may increase Corruption for another. How to increase Corruption is something decided upon by the GM and the player. Making a successful Forbidden Lore + Know test may give the PC insights into how to do this.

Generally, an act increasing power must involve some sort of cost or sacrifice, be it expressed mechanically through the game or socially through the relationships with others in the game world. Any given act should increase Corruption by +1. In nearly all cases, gaining Corruption through this means should almost always be a consequence of a player’s choices, not mandated by the GM as another form of “damage” for something beyond the player’s choice. An exception, such as being accidentally exposed to the insidious and uncontrollable influence of chaos might be acceptable if both players and GM have agreed to this beforehand. Even so, the gain of the last sixth point of Corruption should always be a consequence of a decision made by the player.

Consequences of Corruption

The exact nature of the consequences is determined by the nature of magic, but usually when Corruption reaches 6 the character is consumed by their power in a dramatic manner and their fate is determined in the current or next session as agreed upon by the player and the GM. Individual increases in Corruption at the lower levels may also involve some sort of consequence. The exact nature of these consequences is contingent upon the nature of the forbidden power. Examples below.

Possible Consequences:

Each point of Corruption provides insight into the dark and terrible. Each point of Corruption gives the PC the skill of Forbidden Lore and every time Corruption increases, this skill increases. This may allow access to new spells if suitable.

Alternately, rather than Corruption also creating a "Forbidden Lore" skill, it could instead create a new "Sorcery" skill with access to a new field of dark magic.

At each or every other stage, the PC may acquire an advantage or disadvantage.

The GM may tie the Corruption system to the Unnatural/Supernatural Madness Meter

A sample set of consequences tied to a particular magic is provided below:

Fey Blood:
The Nature of Fey’s Bood: There are some people whose blood conceals a secret: they have the blood an ancient, older people long retired from the world known as the Fey. It is this secret nature that has given them the natural predilection towards Sorcery.

Corruption Idiom: The Fading or "Twilight"

Other Uses for Corruption/The Fading: The Fading may be used for any Charm or Command skill used to entertain or deceive as well as for Counterspell and Eerie.

01: Access to Forbidden Lore: The Fey
02: Gain advantage “Beauty 1”
03: Lose a Passion, -1 to any sincere interactions with humans
04: Lose a Passion, Gain Advantage: “Lucky”
05: Lose a Passion, Gain Problem “Unwholesome”
06: PC fades into the Fey World