Ideas for Running FATE Core Cthulhu


While aware that there is a WWII Cthulhu FATE Kickstarter called "Achtung! Cthulhu" in the works, I asked the folks on the FateRPG Yahoo!Group for ideas about how to run a Cthulhu game using FATE Core.

Some ideas I had off the top of my head for tweaks to the Core system for Cthulu included:

1. A skill pyramid with Great (+4) as the pinnacle skill (typical for FATE Core), since as everyman characters, Skills are our strong suit here.

2. Only two free Feats instead of 3 (Fate Core usually grants 3 free Feats) since the PCs are not heroic characters. (Additional Feats can be bought at the cost of Refresh, per usual.)

3. Less refresh. Maybe only 2 instead of 3 FPs to start...or even 1 instead of 3, since the PCs are squishy.

Specifically, I requested from the Yahoo!Group:

1. Monster stat blocks for Cthulhu horrors

2. Ideas for Stunts, Spells, Extras, etc. for a Cthulhu setting

3. Just a general design philosophy for creating a Cthulhu game

Some brilliant feedback included the following advice:

:5: A Corruption stress track: 4 boxes, each worth *one* shift, and nothing gets you more of them. Whenever you commit a corrupting act (in Freeport it's generally to do with magic used for cruel purposes, but of course that's subject to alteration for a Cthulhu setting), you check one (or, in rare cases, two) of those boxes. If you don't have boxes to check, you have to start using your Consequence slots for things like "Pus-filled boils", "Megalomania," "Aura of Disease," etc. The thing about Corruption is that you need to atone to get rid of *any* of it, including ticks on the stress track, and you can only remove corruption (whether stress or consequences) at milestones.

:5: Madness is handled with "triggers" (awful things happening -- finding a mutilated corpse, having a dead body start moving, a misshapen dog starts talking to you in a dark alley), which you must overcome with (in Freeport) a Wisdom roll. Different severity triggers require different levels of opposition, and as usual, you tick mental stress boxes (or take appropriate mental consequences) if you fail.

:5: keep the "god" level nasties off stage as much as possible. Give the characters and the players ample reason to fear them, but avoid direct confrontation when ever possible. The things are just too powerful and giving them game mechanics diminishes them. Cultists (or scientists who don't realize what they are dealing with) make great antagonists, the more so if the players can be made aware of just how un noticing if not inimical to humanity these things that the cultists choose to serve are.

:5: Set up human relationships for the characters. Make sure they are engaged with the world and have reason to care if the monsters win. Instead of threatening the character directly, threaten her husband or her children

:5: Some sort of mechanic for tracking the mind attempting to confront and deal with the un-reality of the Mythos is almost essential. Characters should feel their humanity slipping away. "He who fights monsters should take care lest he become a monster"

:5: Giving creatures strange immunities and vulnerabilities will help convey the alien nature of the Mythos.

:5: Have magic of some kind work, maybe based on folklore. Perhaps these traditions contain a grain of truth about the true nature of reality.

Elsewhere on the internet I found these bits:

New Skill: Mythos
Understanding Mythos books, inscriptions etc.
Create Advantage: Recognize monsters, spells, rituals, significant constellations etc.
Your Mythos skill is also the Weapon Rating of all mental attacks from Mythos creatures and knowledge (you'll typically defend with Will against this, incidentally). Damn your luck.
No character can start with the Mythos skill, unless the GM (AM for Asylum Master/Mistress?) rules otherwise
Only with the Ritualist stunt (FATE Core, p. 91) and an appropriate spell.
Design Notes:
Basically, understanding stuff is free (though it will take some milestones for characters to get a significant Mythos skill), but using spells costs a Stunt (making the cost for spellcasting 1 skill + 1 refresh; no need for a character aspect, the campaign aspects undoubtedly have that covered). As people learn more about the Mythos, however (as they increase their skill), they enter the rapid down-spiral of growing more insane. Yay!

New Stunts

Ritual Magic: Allows the character to perform ritual magic with his Mythos Lore skill. Spells are strictly limited to those found in Mythos books. There is no way for a human to perform magic effects on the fly.

Dreaming: The character is able to enter the Dreamlands voluntarily.

Creature Lore: The character gets +2 for identifying creatures.


Extra: Cult of Nyarlathotep
Permissions: None; assumed as part of the game’s premise.
Costs: A special pool of aspects, skill ranks, and stunts.
The Cult of Nyarlathotep is subtle among the cults of the world. As myriad and wayward as the Crawling Chaos himself, they take many forms, share much alike, and comprise a complicated web of alliances, enemies, and neutral cults. Each of Nyarlathotep’s cults is different, whether it be subtly or wildly. Regardless, they all hold a few skills in common...
Aspects: 1,000 Forms; Habitual Liars; Ever-Changing
Skills: Deceit (Great +4), Mysteries (Good +3), Stealth (Fair +2), Empathy (Average +1)
Stunts: Takes One to Know One: The Cult of Nyarlathotep may use Deceit instead of Empathy to find out if another cult is lying to them. See Pg. 137-138, Spirit of the Century core rulebook for more details.

Extra: The Cult of Azathoth
Permissions: None; assumed as part of the game’s premise.
Costs: A special pool of aspects, skill ranks, and stunts.
Worshipers of Azathoth are a curious lot. Known as being an insane and fanatic lot, even for a Cult of the Old Ones, they are known as raving madmen who drive others into their fold against all odds. Many other cults avoid them, for fear of their tremendous powers, and especially for fear of truth behind the rumors of how big the cult might really be...
Aspects: Vast Conspiracy; Completely Insane; Bringers of Madness
Skills: Mysteries (Great +4), Contacting (Good +3), Resources (Fair +2), Deceit (Average +1)
Stunts: Words of Madness: The Cult of Azathoth may use Mysteries to inflict Mental stress and consequences against other cults or characters.

Extra: The Cult of Shub-Niggurath
Permissions: None; assumed as part of the game’s premise.
Costs: A special pool of aspects, skill ranks, and stunts.
The Cult of Shub-Niggurath are what you’d call wild cards. Little is known of Shub-Niggurath, her powers, or her servants, but she receives great worship all the same. She is regarded as a fertility goddess, and it seems grand perversions and tremendous parties appease her. As such, her worshipers are debauched and carefree, with a reverence for nature and a disregard for their own and others’ safety.
Aspects: Perverted; Grand Resources; Secretive
Skills: Rapport (Great +4), Resources (Good +3), Gambling (Fair +2), Contacting (Average +1)
Stunts: Swift Corruption: For a fate point from an allied player, the Cult of Shub-Niggurath may make allies in a new area, given a chance to plant their cult’s roots.

Extra: The Cult of Yog-Sothoth
Permissions: None; assumed as part of the game’s premise.
Costs: A special pool of aspects, skill ranks, and stunts.
Sorcerers and geniuses all worship Yog-Sothoth, for he provides them with the greatest secrets of that which is. Those who worship Yog-Sothoth are steeled against some of the most horrific things the universe can offer, for they have already experienced them firsthand. They have limited control over the world at large, preferring to manipulate and scheme over the ones that do.
Aspects: Vastly Knowledgable; Insidious; Secret Rulers
Skills: Resolve (Great +4), Mysteries (Good +3), Deceit (Fair +2), Leadership (Average +1)
Stunts: Lies Run on Many Feet. When this cult uses a third party to deliver a lie to an enemy or other cult, they gain a +2 Deceit bonus. See Pg. 421 of Strange Tales of the Century for more details.

Extra: The Cult of Cthulhu
Permissions: None; assumed as part of the game’s premise.
Costs: A special pool of aspects, skill ranks, and stunts.
The Cult of Cthulhu is by far the most organized and tenable of the cults. With resources at their disposal not of this earth, bizarre creatures at their command, and even promises of immortality and wealth beckoning them ever on, nothing stops the never-ending march of the Cult of Cthulhu.
Aspects: Esoteric Orders; Resourceful; Disturbing
Skills: Intimidation (+4 Great), Resources (+3 Good), Survival (+2 Fair), Mysteries (Average +1)
Stunts: Terrifying Reputation: Members of the cult have a +3 bonus on the first Intimidation roll per scene against enemy cultists and civilians, as long as they are posing openly as a Cultist of Cthulhu.

Extra: The Cult of Hastur
Permissions: None; assumed as part of the game’s premise.
Costs: A special pool of aspects, skill ranks, and stunts.
The Cult of Hastur, artists and dilettantes and maniacs all. Madder even than the Cult of Azathoth, they treat their madness as a form of performance art. Everything is done for Hastur, to impress the King in Yellow, and to make them performers and characters in his next grand and magnificent play. They value intellect and creation over the subversion and destruction, making them hated enemies of the Cult of Nyarlathotep.
Aspects: Madmen and Artists; Creators of Destruction; Utterly Deranged
Skills: Arts (Great +4), Academics (Good +3), Science (Fair +2), Contacting (Average +1)
Stunts: The Weight of Reputation: This cult can use Arts instead of Intimidation to create advantages based on the fear generated by the sinister reputation they’ve cultivated for themselves and all the shady associates you have. You should have an appropriate aspect to pair with this stunt.

Monsters (My Own Design)

Appearance: flopping, hybrid, winged things that no sound eye could ever wholly grasp, or sound brain ever wholly remember; they are not altogether crows, nor moles, nor buzzards, nor ants, nor vampire bats, nor decomposed human beings, but something among all of these; they flop limply along, half with their webbed feet and half with their membranous wings.
Aspects: An Appearance that Defies Memory, Avian Servitor of Hastur the Unspeakable
Skills: Great (+4) Provoke, Good (+3) Physique, Fair (+2) Fight
Extra: Fly Through Space: A byakhee can fly through space and can carry a rider, though the rider needs protection from the vacuum and cold by suitable spells or potions. A Byakhee's natural habitat is interstellar space, but it may be summoned to Earth to perform tasks or to serve as a steed.

Aspects: Enormous, Covered in Viscous Goo, Avoids Daylight
Skills: Superb (+5) Provoke, Great (+4) Fight and Physique
Stunts: Heavy Hitter: When a Dhole succeeds with style on a Fight attack and chooses to reduce the result by one to gain a boost, it gains a full situation aspect with a free invocation instead.

Dimensional Shambler
Appearance: Short crouching creatures with tight grey mummy-like skin; its head is equal parts simian and canine, and has crooked stained fangs; its eyes are recessed in deep eye holes and appear as yellow slits; it has long arms with huge claws.
Aspects: Hunter from Beyond, Reeking of the Fumes of Hell
Skills: Good (+3) Provoke, Fair (+2) Will
Immaterial: While Dimensional Shamblers do have the appearance of being material and grabbing at their victims with their long arms, their origin in a different dimension makes them immaterial in our world, and therefore unable to touch or be touched. Hence, they have no Physical Stress track in this dimension, and can only be attacked magically on their Mental Stress track.

Dimension Suck: Because Dimensional Shamblers have no material form in this dimension, they actually use a form of hypnosis to suck a victim into their own dimension, where the victim is then consumed by throngs of Shamblers. When a Dimensional Shambler does this, it will seem as if the place around the Shambler disappears behind it and its own dimension will become visible. A Dimensional Shambler can use Provoke as an attack against a victim's Will. If the victim is Taken Out in this way, he or she is sucked into the Shambler's dimension and consumed.

Flame Creature of Cthugha
Appearance: a point of fiery light
Aspects: Aflame, Dangerous in Packs, Servitor of the Great Old One Cthugha
Skills: Good (+3) Provoke, Fair (+2) Will, Average (+1) Physique
Extra: Upon appearing, Cthugha's flame creatures ignite every flammable object they touch, giving it the aspect "On Fire"

Hound of Tindalos
Aspects: Lean and Athirst, Oozing Pus
Skills: Fair (+2) Fight and Provoke
Stunts: Draining Proboscis: Once per scene, when a Hound of Tindalos forces an opponent to take a
consequence, it can spend a fate point to increase the consequence’s severity (so mild becomes moderate, moderate becomes severe). If the target was already going to take a severe consequence, he must either take a severe consequence and a second consequence or be taken out.

Appearance: while technically fungi, Mi-go bear a great resemblance to crustaceans, namely shrimp or crayfish; roughly man-sized, elongated bodies with segmented bands of muscles and a mass of sensory cilia for a head; a pair of ribbed, vestigial wings
Aspects: Humaniform Fungus, When in Rome
Skills: Great (+4) Lore, Good (+3) Deceive, Fair (+2) Stealth and Rapport
Stunts: Biotechnology: Mi-go have mastered various fields of science, are especially adept at surgery, and can do things such as extensively modify their own bodies, or remove human brains while keeping both brain and body alive (this allows the Mi-go to transport Human allies off-world, as the brains can be allowed to see and communicate when hooked up to special machines). A Mi-go gains a +2 when using Lore to begin a healing process or to conduct any type of medical or surgical procedure.

Star Vampire (Very Large Monster)
Appearance: red and dripping; an immensity of pulsing, moving jelly; a scarlet blob with myriad waving tentacular trunks tipped with suckers opening and closing with a ghoulish lust; bloated and obscene; a headless, faceless, eyeless bulk with the ravenous maw and titanic talons of a star-born monster; human blood on which has fed reveals its hitherto invisible outlines
Aspects: Blood-covered But Otherwise Invisible,
Skills: Superb (+5) Provoke, Great (+4) Physique, Good (+3) Fight, Fair (+2) Will
:1: Mass Chaos: when creating advantages, such as "Panicked Crowds" or "Falling Buildings" and compelling the heroes using the free invokes created by the rolls, the Star Vampire gets two free compels instead of just one.
:1: Reach: a Star Vampire may make a Fight roll against targets in adjoining zones.
:1: Grappler: a Star Vampire gains +2 to Physique rolls made to create advantages on an enemy by wrestling or grappling with them.
:1: Crush and Suck: a Star Vampire treats any Fight roll against a Grappled target as if it is attacking with a +2 weapon.
Extra: as a Very Large Monster, the creature itself is treated as a map with several zones: its blubbery body and 5+4dF tentacles (i.e., 1-9 tentacles), each part having 3 Stress boxes and capable of sustaining Mild, Moderate and Severe Consequences. In order to defeat the monster, the characters need to defeat each zone independently, while navigating the obstacles between the zones, or may need to target one zone with a particular plan (like closing a portal or activating a device).

Yithian Host
Aspects: Non-linear Thinker, Fascist, We Never Speak of the Flying Polyps
Skills: Superb (+5) Lore; Great (+4) Crafts and Investigate; Good (+3) Deceive, Empathy, and Notice; Fair (+2) Physique, Resources and Provoke; Average (+1) Rapport, Stealth and Will
Stunts: Mind Projection: Instead of being Taken Out, the Yithian consciousness of a human host may jump to another host, assuming a suitable host is available in the same or adjoining zone, by succeeding in an Empathy attack roll against the new target's Will. Failure means the Yithian consciousness is prevented from possessing the new host, and if a suitable host cannot be found within one Exchange, the Yithian consciousness dies, and the original consciousness of the host returns to its body. Success, however, renders the original host a depleted shell, and the consciousness of that host -- which has been residing within the Yithian's original body, elsewhere -- dies instantly, and is replaced by the consciousness of the new host. The new host's body takes on the Moderate Consequence "Disoriented" even if it already has sustained a Moderate Consequence.

Miscellaneous Lovecraftian Horror (Average)
Aspects: Monstrous Visage
Skills: Average (+2) Provoke

Miscellaneous Lovecraftian Horror (Fair)
Aspects: Monstrous Visage, Avatar of Chaos
Skills: Fair (+2) Fight, Average (+1) Provoke and Physique

Miscellaneous Lovecraftian Horror (Good)
Avatar of Chaos, Incomprehensible Horror
Skills: Good (+3) Fight, Fair (+2) Provoke, Physique (+1) Will and Empathy

Miscellaneous Lovecraftian Horror (Fantastic)
Smashing Tentacles Galore, Agent of Cognitive Dissonance
Skills: Fantastic (+6) Fight, Superb (+5) Physique [Note: 4 physical stress boxes, 1 extra mild consequence for physical conflicts], Great (+4) Provoke
Stunts: Constrictor (Fight): +1 to Fight when using it to Grapple.

Other Adversaries (1950s Setting)

American or Soviet Spy (Average)
Aspects: Shadowy Champion of Capitalism/Communism
Skills: Average (+2) Burglary

Civil Defense Worker
Aspects: Prepared for Almost Anything
Skills: Average (+1) Notice

Government "Top Man" (Good)
Aspects: Leave Nothing to Chance, Devoted to Expanding the Boundaries of Science
Skills: Good (+3) Lore, Fair (+2) Deceive, Average (+1) Will and Empathy

National Park Ranger
Aspects: Trustee of America's Natural Resources
Skills: Average (+1) Lore and Notice
Stunts: Walker in the Wild: Gain +2 to Lore rolls regarding nature.

Psychic Human
Aspects: Hunted by the First World and Second World Alike
Skills: Superb (+5) Empathy, Great (+4) Notice, Good (+3) Investigate, Fair (+2) Will
Mind Shard: Once per session, you can use Will as a Weapon +2 instead of Fight.

Trained Enforcer (Fair)
Aspects: Big and Strong, Cunning
Skills: Fair (+2) Fight, Average (+1) Athletics and Physique

Roy Cohn, Anti-Communist Witch-hunter
Aspects: Legal Eagle, McCarthy's Right-hand Man, I've Got My Eye on You
Skills: Great (+4) Investigate, Good (+3) Provoke, Fair (+2) Will, Average (+1) Shoot
Stunts: Hold Court: Can use Provoke to create advantages in large-scale tactical situations.

Boris Kvasnikov, Head of Scientific & Technical Intelligence
Aspects: Red Army Training, No Barriers Can Stop Me
Skills: Superb (+5) Burglary, Great (+4) Stealth, Good (+3) Lore, Fair (+2) Fight, Average (+1) Physique [Note: 3 physical stress boxes]
Stunts: Inside Man: +2 to Stealth in an indoor urban environment.

Lona Wovshkin, Possible American Defector to the Soviet Union
Aspects: All-American Upbringing, College Degree in Engineering, I Married a Spy, Cipher Expert, Always Underestimated, I Do What Must Be Done, Smuggler Extraordinaire
Skills: Fantastic (+6) Deceive and Provoke, Superb (+5) Shoot and Burglary, Great (+4) Resources and Will, Good (+3) Contacts and Notice, Fair (+2) Crafts and Stealth Average (+1) Lore and Empathy
Stress: 3 Physical Boxes, 4 Mental Boxes
Stunts: Takes One to Know One: Use Deceive instead of Empathy to create an advantage in social situations.
Feint Master: +2 to use Deceive to create an advantage in a physical conflict.
Always a Way Out: +2 on Burglary rolls made to create an advantage whenever trying to escape from a location.

Adventure Seeds

What if a physicist at CERN tries to develop a way to tap into Azathoth as an energy source...

What about Nyarlathotep playing politics for his own amusement, how are the Great Powers being manipulated and to what end?

Genetic engineering certainly plays well with Lovecraft's concerns of racial purity. Could Deep Ones be created by engineering fish or frog DNA into people? Perhaps with the goal of using tissue regeneration to help reverse paralysis Or amputation?

What about the Fungi from Yuggoth? They are an advanced life form completely alien to terrestrial biology, they can't even be photographed with a standard camera. What advances could they offer in the field of neuroscience?

If anyone has anything they'd like to add with respect to ANY aspect of this game, please do so! All input is welcome!
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Fascinating....I will be watching and contributing as our work schedules allow our Fate Core game, inlfluenced by Cthulhu and Atlantis, and based on the US East Coast continues.


Found these suggestions on Black Dog of Doom's blog. Some stuff has been tweaked from Fudge to FATE Core:

Sanity and Going Mad

There is no Sanity statistic, but do not fear, characters will go mad!

Rather than tracking a figure for Sanity as the CoC system does, under FATE I suggest that you instead allow the characters to acquire negative aspects grouped under the heading of “Insanities”.

The Sanity test used under CoC system is paralleled under this modification to FATE. As already mentioned characters do not have a SAN statistic, but are under this system assumed to have a Sanity “skill” at the “Mediocre” level. If the characters come across a mutilated corpse or some such trivial horror they should make a die roll against a skill level of “Average”. if they successfully meet that challenge then the character does not suffer any ill effects. however if they fail...

If they meet a mythos beastie then the difficultly level level would be higher. Set the level as seems appropriate.

The CoC rules suggest that temporary insanity is often accompanied by a temporary phobia. Such a phobia can be tracked in this system as a negative Aspect, and rather than being temporary, they should be considered permanent. In CoC the rules suggest the phobia should be linked to the experience that created it and that should also apply under these rules.

As with standard Attributes phobias can be duplicated, so you could end up with something like the following :




Do not limit Insanities to just phobias however, any number of other behaviours can be added to the character sheet under Insanities, for example:


Obsessive hand washing


The player can ignore the aspect, considering the character to be overcoming any issues, until the aspect is invoked by the player or the GM.

This allows the player to continue playing with even the most insane PC, but the number of insane events that take place will increase. The compelling of such aspects means that the player will find that the restrictions imposed by the insanities, is balanced by the number of Fate points received. Remember, many people considered insane have achieved great things, so these additional Fate points will allow the character to shine!

Mythos Tomes and Spells

Reading Tomes

Mythos tomes often have spells within and the horrid truth about the nature of reality that can shake a persons sanity. Unlike in CoC, simply reading a Tome under these rules does not cause any Sanity loss or automatic spell gains.

The reading of such a Tome of uncommon lore requires effort and time. Depending on the books obscurity or value, set an appropriately difficult Static Challenge and limit the progress to perhaps one roll of the dice per game week.

Once a character has completed the challenge they gain one of the spells therein. They do not gain any Insanities at this point. Only when a spell is first successfully cast does it move from obscure theory to reality and its at this point the character should gain an appropriate Insanity. The GM on his own or in discussion with the player decide what the Insanity may be. Remember this only happens when the spell is first cast, not on each subsequent re casting.

Having read a Mythos Tome the character is eligible to select the “Cthulhu Mythos” skill during the next Advancement. Once gained this skill is treated as other skills and can only be advanced in the usual pyramid method. If the character has not read a Mythos Tome they may not select the skill during Advancement. The skill can only be improved if the character has read another Mythos Tome since the last Advancement.

Casting Spells

If a character has a spell it is listed on their character sheet in the same manner as an aspect (although not treated as an aspect).

Summon Mi Go


Summon Wind

To cast a spell the player spends a fate point, states they are casting the spell, has the character spend the appropriate time incanting/sacrificing, and rolls 4 fudge dice. A positive result indicates the spell is successful.

Once a spell is cast, tick it, as if it were an Aspect you had just used. That character may not cast that spell again until the next “refresh”, spells refresh at the same time as Aspects.


With respect to the suggestions about Corruption and Madness, in the first post, I asked the folks on the Yahoo!Group whether Provoke vs. Will to do Mental Stress Track damage was enough.

One poster answered, "Using Mental stress for Madness is one option, though it means that you can be taken out more easily if you were bullied at school that day. It all depends on what difficulty level you want it to be."

Another poster added:

"Just remember to afflict characters with it. I forgot that FATE has this system already. After all when you take too much mental stress you are out of action, take too much Sanity damage and you are out of action. I was never happy with the way mental illnesses are added to characters as a result of "madness" in Cthulhu gaming. Mental Stress may actually be a better model.

"It is even possible that after enough mental stress has been taken from Things ordinary causes of mental stress will no longer affect the character. After you have faced down a pack of Ghouls some guy talking smack in a bar just isn't going to get you riled."

Even developer Fred Hicks chimed in, "Don't be afraid to turn away from Sanity Damage as a meme in all of this, too. That's something that the original Call of Cthulhu trained us all to think of automatically for Mythos gaming, and as such folks don't think outside that particular box very much."

Some voices of dissent, noted, however:

"Trail of Cthulhu has both a Sanity rating and a [mental] Stability rating. Not all mental stress is going to affect your sanity, and you can be relatively stable even if you're suffering from a mental illness. If I was running a Lovecraftian Fate game, I'd definitely keep the Mental track and add a Sanity track."


"Madness really is just a use of the standard Mental Stress track and consequences, and would be cleared as in the Core rules. It's not so much a new set of rules as it is a set of suggestions for the kinds of things that would cause the stress, and what kinds of consequences would be appropriate.

"I like the Corruption stress track idea because it inflicts serious costs to willingly interacting with things man was not meant to interact with. You want to read that book? Sure, that will give you the ability to take a spell casting stunt at your next milestone -- and right now it will fill two Corruption boxes. I like that it lasts longer than Mental Stress would, and that you don't get any kind of roll to mediate it -- you take stress, period, and it stays with you until you take some real action to get rid of it."


First Post
I agree with keeping the normal skill pyramid (with the caveat below). CoC characters aren't adventurers, but they're generally skilled in their profession. I'd discourage anyone from taking a combat skill at Great, or probably even Good, because of that. Being a Great historian makes sense. Being a Great sniper does not.

I like the Mythos skill you have up there.

I would create a sanity stress track, myself. Stress tracks should be made based on the genre and setting needs. For example, in my Fallout game, there is a radiation stress track. Insanity would make great consequences from the new sanity stress. Remember to keep in mind the Fate Fractal. Situations are characters. So if the PCs end up seeing something that would normally make an attack against their sanity. ("Walls can't have eyes!" Attack +3 vs. Will) then hit them for sanity stress. Keep doing it, and they'll eventually take some consequences, in the form of psychiatric disorders. (They're Always Looking At Me). I wouldn't create a new subsystem for these aspects. I'd make the insanity consequences take up the same slots as the physical ones. That's just the dangers of investigation in the CoC world!

Mental stress would still exist, but it would be fore more mundanely stressful things that normal people would find difficult to deal with. This makes it a distinction between the crazy stuff and the really crazy stuff that happens in a CoC game. Being chased by a pack of wild dogs is going to cause you mental anguish. Being chased by a pack of wild dogs with three green glowing eyes, smell like garbage, and are covered in thumb sized insects is going to make you question your sanity.

I'd lump the corruption stress mentioned above (casting spells, using mythos artifacts, etc.) into mental stress. Its taxing on the mind.

Lore should be replaced by more exacting fields: History, Archaeology, Latin. Egyptian, Research, Medicine. This represents I'd probably increase the number of Average skills PCs have by one or two because of the increased number of skills.

Those are thoughts and ideas off the top of my head.

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