Sandy petersens cthulhu mythos (1) 163

Rolling a natural 20 on a research check acts like a

the potential insanity or not. Award an amount of

critical threat. If the researcher confirms the critical

experience as if the characters defeated a foe of a CR

hit by succeeding on a second research check with all

equal to one-fifth to one-third the book's complexity,

the same modifiers (this takes no additional time), two

depending on the level of risk and/or challenge.

further relevant facts are revealed. Conversely, rolling
a natural 1 on a research check automatically results in
failure, and the next check takes 16 hours instead of 8,
doubling the duration of any dread resulting from that
research check (if the researcher's save fails; see below).

The Risks of
Mythos
Research
Every

research

Due to the depth and complexity of its content, each of
these books grants a bonus on skill checks for skills used

for research checks for that book. A book's entry also
notes if it allows skill checks untrained. A successful
research

check

is

required

sometime in the month before
attempting the skill check to
which the bonus is to be applied.
made

The researcher must specify the

with one or more Mythos books

type of skill used but need not

exposes the reader (and anyone

know the exact circumstances

providing

aid)

ahead of time. For example, the

unhealthy

for

check

to

concepts
minds

researcher may choose to use

Regardless

the Knowledge (arcana) skill,

of whether a research check

resulting in identification of

succeeds, the reader must make

a spell or arcane topic, while

a saving throw against dread. The

use of the Craft (alchemy) skill

save DC of this dread is either

might apply to identifying the

to

mortal

contemplate.

equal to the book's shock rating or
as normal for a disturbing discovery (see Chapter
4) relevant to the topic being researched, whichever
is higher. Because disturbing material permeates each

156

Skill Bonus

ingredients and effects of a poison.

Spells, Rituals, and Item
Creation Instructions

text, no topic can be researched that avoids this risk,

Many Mythos books contain spells and rituals, but each

except in very unusual circumstances (entirely at the

requires a successful research check to recognize them

GM’s discretion). The dread from this research lasts

as such in addition to the normal difficulties of reading

for 1d3 days or the normal duration for the disturbing

spells and rituals. Some also include instructions for

discovery, whichever is longer.

creating magic items or alchemical items. A book's

If the dread risk or other non-combat challenge

skill bonus always applies to checks to learn a spell or

related to researching a book's contents is a significant

ritual from that book as well as to Craft or Spellcraft

one for player character researchers, the GM is

checks made to create an item from instructions in that

encouraged to award experience points upon a thorough

book. All spells in these books are found in Chapter

and significant discovery, whether the characters resist

5. The book's skill bonus doesn't apply to skill checks