While I obviously can’t fully reproduce things from the book here, I can give a general idea of the Forbidden Lore system from “Mirrors”, as well as give the basic chart of the various levels.
Basically, in Volatilis, there are dark secrets hiding in every corner, and while some have the abilities of a thaumaturge or a psychic, they’re only a small portion of the true power some of the creatures of the night wield. This leads some to go digging for more, to make deals with foreign entities or to read a tome said to kill off anyone that looks at it. Or perhaps they just put themselves in positions where they may stumble into something they shouldn’t, and their world view is shattered as new capabilities overwhelm them.
Whatever the case, once the game gets started, characters may start to accumulate powers from ANY game line, so long as they’re still mortals, at the cost of their “Reason”. In short, “Reason” starts at 10, and for each power learned through various circumstances, they lower this by one point, giving them a disconnect from mundane society, but power formerly unknown to them, and eventually even a better occult understanding because of it.
Using these powers builds “Insanity”, at 1 point per each power used, and is lost at 1 point per night’s sleep, 3 points per willpower spent, or 5 points per visit to a psychiatrist or similar. If Insanity gets up to 10, it resets, but Reason is lowered by another point.
All characters start off with Reason 10 and no Forbidden Lore at creation.
|9||–1 to all Social Skill rolls|
|8||–1 to resist the effects of a derangement|
|7||–1 to avoid gaining a derangement||+1 to all Occult Skill rolls|
|6||Increase the above penalties to –2, reduce any bonus gained by spending a point of Willpower by one (+3 dice to a roll becomes +2, the +2 bonus to Resistance becomes +1, etc.)|
|5||Reduce one Social or Mental Merit to the lowest possible rating or lose access to a single Social or Mental Merit**, the character may not eliminate derangements by increasing Morality||Gain a free Occult Specialty|
|4||The penalties for Social Skill rolls* and to resist gaining a derangement are increased to –3, derangements may only be suppressed by spending a point of Willpower.||+2 to all Occult Skill rolls|
|3||Reduce the bonuses gained by spending a point of Willpower by two (minimum of one), the character automatically gains a derangement after degeneration||A single Attribute selected by the player may now exceed human maximums (no upper limit)|
|2||Reduce a second Social or Mental Merit to the lowest possible by the rating or lose access to a second Social or Mental Merit**, rolls to avoid degeneration automatically fail||A second Attribute selected player may now exceed human maximums, +3 to all Occult Skill rolls|
|1||The penalty to Social Skill rolls is increased to –5*, eliminate all remaining Social and Mental Merits||A third Attribute selected by the player may now exceed human maximums|
|0||The character is so detached from reality he becomes unplayable and is removed from player control|
*Excluding Intimidate and Streetwise. These penalties don’t apply to Whisperers or Supernaturals.
**This only applies to Merits currently possessed by the character and excludes Language and Resources (as well as Supernatural-focused merits). Characters without either Social or Mental Merits may not purchase new ones without Storyteller approval (and a really good justification).