Forbidden Tomes and Knowledge

Character Sanity Scores

Sanity, Insanity and Disorders

Loss of Sanity

Types of Insanity

Indefinite Insanity and Disorders

Gaining or Recovering Sanity

House Rules

Reading Forbidden Tomes

Obscure tomes add ranks to a character’s Knowledge (forbidden lore) skill (see below), and allow them to learn certain forbidden arcane spells and rituals. Studying and comprehending these books causes all that we know to become like shadows. The burning power of a greater reality seizes the soul. Whether we try to retreat from the experience or hunger greedily for more, it destroys our confidence in what we once believed, opening us up to the all-encompassing truths of dark deities.

For each such book encountered, the GM must set the examination period, the Knowledge (arcana) DC to understand it, the number of spells contained in it, the Sanity loss that occurs upon beginning the examination, the Sanity loss that occurs upon completion of the examination, and the ranks of Knowledge (forbidden lore) gained from studying the book. While the GM is free to set these parameters at any values that he feels are appropriate for the campaign or adventure, Table: Example Forbidden Tomes provides some suggested combinations of each of these parameters.

Table: Example Forbidden Tomes

Examination Period Knowledge (arcana) DC to Understand Tome Number of Spells/Rituals Contained in Tome Initial Sanity Loss Sanity Loss upon Completion Knowledge {forbidden lore) ranks gained
1 week 20 0 1 1d4 1
1 week 20 1 1d4 1d4 1
1 week 25 2 1d4 2d6 1
2 weeks 25 1d4 1d6 2d6 2
2 weeks 25 1d6 1d10 2d6 2
2 weeks 25 3 1d6 2d6 2
2 weeks 30 1d6+1 1d6 2d6 3
3 weeks 20 1d4+1 1d10 2d6 2
3 weeks 25 1d6 1d6 2d10 2
3 weeks 30 1d4+5 1d10 3d6 3

Forbidden Knowledge

The Sanity rules assume that some knowledge is so alien to human understanding that simply learning of its existence can shatter the psyche. While magic and nonhuman races form an everyday part of a character’s life, even a seasoned adventurer cannot conquer or understand some things. Knowledge of these secrets and creatures is represented by a new skill that goes hand in hand with a character’s Sanity score: Knowledge (forbidden lore).

This type of knowledge permanently erodes a character’s ability to maintain a stable and sane outlook, and a character’s current Sanity can never be higher than 99 minus the modifier the character has in the Knowledge (forbidden lore) skill. This number (99 minus Knowledge [forbidden lore] ranks) is the character’s maximum Sanity.

Knowledge (Forbidden Lore) (None)
You know That Which Should Not Be Known. You have had horrible supernatural experiences and read forbidden tomes, learning truly dark secrets that have challenged everything you thought you knew. Since these revelations defy logic or commonly accepted fact, it does not matter how intelligent or wise you are when using this skill—only how much exposure to these dark secrets themselves you have experienced.
Answering a question about the horrible deities and secrets that lurk at the edges of reality has a DC of 10 (for really easy questions), 15 (for elementary questions), or 20 to 30 (for difficult or really tough questions). Unlike in other fields of study, there are almost no really easy questions associated with this dark knowledge.
You can use this skill to identify monsters and their special powers or vulnerabilities. In general, the DC of such a check equals 10 + the monster’s HD. A successful check allows you to remember a bit of useful information about that monster. For every 5 points by which your check result exceeds the DC, the GM can give another piece of useful information.
The GM can decide which monsters are subject to the Knowledge (forbidden lore) skill and which monsters are subject to one of the standard Knowledge skills. For example, the GM may rule that Knowledge (the planes) is still the relevant skill for learning or knowing about outsiders, rather than allowing them to be iedntified by Knowledge (forbidden lore). However, in most campaigns that use the Sanity variant, aberrations and oozes should be able to be identified by Knowledge (forbidden lore) rather than by Knowledge (arcana) and Knowledge (dungeoneering) respectively.
Usually none. In most cases, making a Knowledge check doesn’t take an action—you simply know the answer or you don’t.
Try Again
No. The check represents what you know, and thinking about a topic a second time doesn’t let you know something that you never learned in the first place.
You cannot gain ranks in this skill by spending skill points. You can only gain ranks by reading forbidden tomes or having experiences with horrible creatures. Each rank you gain in this skill permanently reduces your maximum Sanity by 1 point: The more you know about the horrible truths underlying reality, the less capable you are of leading a normal life.

A character’s first episode of insanity (that is, an occurrence of temporary or indefinite insanity) bestows 2 ranks in the Knowledge (forbidden lore) skill, thereby lowering his maximum Sanity by 2 points. Each time a character fails a Sanity check and endures another episode of insanity, he gains an additional rank in Knowledge (forbidden lore).

For example, Caldark has 1 rank of Knowledge (forbidden lore) after reading a strange manuscript. She then steps outside, sees a chaos beast, and goes indefinitely insane, her raving mind failing to understand the strange creature she has encountered. Since she has never gone insane before, her player adds 2 ranks of Knowledge (forbidden lore) to Caldark’s character sheet. Now Caldark’s Maximum Sanity is 96 (99 minus 3 ranks of Knowledge [forbidden lore]).

You cannot take the Knowledge (forbidden lore) skill during character creation. However, the skill has no maximum rank; your level does not limit the number of ranks in Knowledge (forbidden lore) that you can acquire.

Forbidden Tomes and Knowledge

Crimson Skies PhoenixMark