Reading Tomes


Rules taken from the “Mythos Tomes in Play” section of the Miskatonic University sourcebook.

Mythos Tomes as Reference Works

A researcher seeking a specific fact about the Cthulhu mythos (the name of one of Nyarlathotep’s forms, the home star of the lloigor, weaknesses of nightgaunts, etc.) may use a mythos tome as a reference. The keeper must decide, based on the work’s described content, if the data sought can be found within the tome—the researcher will not know unless he has skimmed or read the book. The Necronomicon is the one exception: it always contains the information sought.

The researcher spends 1D4 hours poring through the tome. To learn the fact even from the Necronomicon, the player still must make a D100 roll less than or equal to the work’s Cthulhu Mythos bonus x5.

EXAMPLE: Wolfe, intrigued by a strange symbol on a dagger, tries to find a reference to it in Ye Booke of Eibon. The symbol happens to be the Sign of Koth, which is indeed described in Eibon’s tome. After two hours of research, Franklin’s player must roll a 55 (+11 Cthulhu Mythos x5) or less on D100 for the character to find the information. The researcher also might look in Dee’s Necronomicon, where he or she would have a 75% chance of success.

Quaint and Curious Volumes: Progressive Sanity Loss

The secrets held within mythos tomes are not in and of themselves destructive, and most readers will dismiss the arcane ramblings and hideous stories as fiction, or the ravings of the insane. The damage to the reader’s psyche comes from realizing that the contents of a mythos tome might be true, and that, by extension, the investigator’s world view is inherently wrong. The more the reader knows about mythology or ancient history, the greater the danger. While the Call of Cthulhu rules provide a simple, efficient system for handling Sanity loss from mythos tomes, some keepers and players may desire a more realistic approach. In that case, refer to the following rules.

Each mythos tome retains the Sanity cost listed for it in the Call of Cthulhu rules. When an investigator finishes reading the tome, the keeper should secretly roll the amount lost and keep a note of it. Experts in obscure lore will realize that many of the details are too convincing to be ignored, and will suffer a milder shock immediately. More sheltered readers, on the other hand, might read the tome without any loss of Sanity at all.

Each Cthulhu mythos tome has a Base Sanity Cost equal to its Cthulhu Mythos gain divided by ten, rounded to the nearest whole number. Thus, the most potent tomes are so vile and so internally consistent that they will shock their reader regardless of their experiences, but most will not. The base sanity cost is suffered immediately, and should be subtracted from the total Sanity loss for the book. There is no Sanity check to guard against this loss—it is unavoidable.

EXAMPLE: After much research, Dr. Anthony Howell reads the German edition of von Junzt’s Unaussprechlichen Kulten. The book has a listed Sanity loss of 2D8. The keeper rolls and gets a result of 12. Dr. Howell suffers an immediate loss of two Sanity points (the tome’s 15 percentile Cthulhu mythos gain divided by 10 gives 1.5, rounded to 2). The keeper notes that Dr. Howell has 10 points left to lose. Incidentally, Dr. Howell would not immediately lose any Sanity points from reading Thaumaturgical Prodigies in the New England Canaan—Mythos gain of +4 divided by 10 equals .4, rounded to zero.

At this point, the keeper should write down the tome’s residual Sanity loss. One additional Sanity point is lost immediately once any of the following conditions are met.

  • The investigator’s Cthulhu Mythos score is raised above the Cthulhu Mythos bonus for the tome, or is higher to start with. The correlations in disparate works and experiences quickly lead the researcher to frightful conclusions.
  • The investigator makes a successful Know roll. At the keeper’s option, if this roll is failed additional rolls can be made whenever the investigator’s EDU score increases.
  • The investigator’s player makes a successful roll against a skill granted as another benefit for that tome. If those rules are not being used, the keeper should choose an appropriate skill, usually History, Anthropology, or Archaeology, depending on the text (the Ponape Scripture would use Anthropology, while the Zanthu Tablets would use Archaeology. The Necronomicon could use either). Attempt the skill roll immediately upon completion of the tome. Again, cruel Keepers might require another roll each time the investigator’s pertinent score rises above the next multiple of 10; a boost from 48 to 51 would prompt a check, but an increase from 51 to 57 would not.
  • The investigator encounters second-hand evidence that the horrors described in the book actually exist. Photographs, footprints, slime, or fluid samples, and second-hand accounts from a credible source all apply. Just what constitutes a credible source depends on the investigator’s judgement, while Persuade rolls can be used to determine whether or not the account is convincing.

EXAMPLE: Returning to Dr. Howell, the keeper notes the residual 10 point Sanity loss for Unaussprechlichen Kulten. Howell gains 15 points of Cthulhu Mythos, but had none to begin with, and so takes no loss from the first condition. Upon finishing von Junzt, the keeper calls for immediate Knowledge and Anthropology rolls. Howell’s EDU is 16 and he has an Anthropology skill of 35%. Howell’s player rolls a 65, making the Knowledge roll easily. He fails the Anthropology roll with a 50. By making the Know roll, Howell realizes that some of the hideous cults von Junzt describes are plausible, and loses 1 additional point from the Know roll (for a total of 3).

If Howell’s Cthulhu Mythos score ever rises above 15, he will lose another point. Also, Howell might make another Anthropology skill roll when his Anthropology skill rises above 40 (then at 50, 60, etc.) or lose another 2 Sanity points. If Dr. Howell had had a beginning Cthulhu Mythos score of 10 and an Anthropology skill of 70, he would have lost a total of 5 points upon finishing the book (2 immediately, 1 for having his Cthulhu Mythos skill raised above 15 to 25, 1 for the Know roll, and 1 for what would be a successful Anthropology roll). He might go temporarily insane. If, at a later time, Dr. Howell encounters evidence of the existence of ghouls (plaster casts of footprints, police reports of grave robberies and tunnels, or the horrified tale of his friend Dr. Rollings, who visited Pickman’s cellar) he will lose another Sanity point.


One Final Condition

Whenever the investigator is directly confronted with something discussed or depicted in the tome, he or she loses any remaining Sanity loss, all at once. There is no Sanity check to guard against this loss, and the loss is added to any Sanity lost for whatever horror proved the book right. Under these conditions, the Sanity loss from an encountered creature or situation can be devastating. To determine if a particular experience will prompt this final lump sum loss, refer to the listed content of the tome (spell lists can be helpful). Virtually any paranormal experience might validate the horrors of the Necronomicon, and pooled losses for multiple books covering the same topics are cumulative.

EXAMPLE: Dr. Howell has so far lost three of the 12 Sanity points cost by his study of Unaussprechlichen Kulten. Months later, Howell encounters a band of ghouls in the sewers of Boston. He loses 4 points for seeing the ghouls, but also remembers everything von Junzt wrote about the ghoul cults under Paris. Seeing the ghouls, he realizes that everything else von Junzt wrote is true! He loses all 9 points that remain from the tome, changing the Sanity loss for the ghouls from 4 to 13! What would have been a routine Sanity loss could now easily plunge Dr. Howell into temporary or indefinite insanity. For a darker twist of fate, imagine that Dr. Howell had also read the Cultes des Goules, and had 6 points of Sanity loss remaining from it. Those 6 points would also be lost from seeing the ghouls, raising the total loss to 19!

There is a caveat to this final condition. If the reader has already seen things that will prove the book is true (if Dr. Howell, above, had seen ghouls years before reading von Junzt, for example), the reader is subject to the full SAN loss immediately, as soon as the book is finished. The keeper is always the final judge of what an appropriate trigger is, and should be as fair as possible.

Toxic Texts

Some mythos texts fall outside of the above system. These books are so strange and insidious that their contents do strain the researcher’s sanity simply from reading them. The repellent King in Yellow is one of these, a book so strange that whoever reads it dies or is stricken with madness. Sanity loss for these books is handled normally—the full loss happens as soon as the text is finished. At the keeper’s discretion, other tomes might fall into this category: the Revelations of Glaaki, the Revelations of Hali, the Black Tome of Alsophocus, and Wilbur Whateley’s Journal are a few likely candidates.

In many Call of Cthulhu campaigns, investigators often treat mythos tomes like the literary equivalent of toxic waste—to be touched only if absolutely necessary and best secured in some fortified vault and then forgotten. Unfortunately, scenarios often require that the investigators read a tome to be able to overcome the opposing menace, and investigators who actually know a thing or two about the Cthulhu mythos are much more likely to survive an investigation. Using these rules, mythos tomes can be read with a minimum of worry, but are much more dangerous in the long run. Research-oriented investigators will have a high Cthulhu Mythos skill and hold useful stocks of information, but also are walking time bombs: the first extreme shock could be their last. As in Lovecraft’s tales, the more an investigator knows, the more dangerous that knowledge can be.

Reading Tomes

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