Call of Cthulhu 7e Complete Skills List: Base Values and Fields of Study

Introduction

This is the complete Call of Cthulhu 7e skills list: every standard skill, its base value, what it covers, and where it overlaps with its neighbors. Base values below come from the individual skill entries in the Keeper Rulebook and match the Investigator's Handbook entries.

The second half covers fields of study: the Science, Art and Craft, Survival, language, and combat specializations that turn "an academic" into someone who reads a clue differently from everyone else.

Hot Take

A complete skills list is only useful if it makes players more imaginative. Treat it as a menu of investigative approaches, not an optimization spreadsheet. The skill with the highest number is rarely as useful as the skill that fits the person, the setting, and a plan the player can describe.

That goes double for specializations. "I have Science" is not a character idea, and the rules will not let you buy it anyway. "I study botany, so these roots should not be growing in this soil" creates a scene. Pick a field because it gives your investigator a question only they would think to ask.

How to Use This List

Each entry gives a short summary in our own words rather than the rulebook's full description. Use the entries to answer three questions:

1. What kind of action does this skill describe?
2. What other skill might cover a different approach to the same problem?
3. What in the investigator's life would justify this skill on the sheet?

The Keeper picks the skill that fits the declared action. A player can suggest one, but should lead with what the investigator actually does. The Skills Guide covers difficulty, when rolls matter, pushing, and bonus dice.

Skill names are not rigid verbs. Tracing a missing person might use Library Use for records, History for an old institution, Law for public filings, Fast Talk for an uncooperative clerk, or Spot Hidden for a detail in the office. Each route creates a different scene and risk.

How Base Values Work

The base value is what every investigator has before spending points. Most are fixed percentages. A few are not: Dodge starts at half DEX, Language (Own) starts equal to EDU, and Credit Rating and Cthulhu Mythos start at 0%. Specialized skills list a base for each specialization. The rulebook's scale for reading any value: 01% to 05% is a novice, 20% to 49% is hobby level, 50% to 74% is professional, 75% to 89% is expert, and 90% or more is among the world's best.

The Investigator's Handbook's quick-reference list gives a few Science and Art and Craft values that disagree with its own skill entries (Forensics, Forgery, and Mathematics). This page uses the full skill entries, which match the Keeper Rulebook.

Investigation and Knowledge Skills

These skills find information, interpret it, or recognize what the group has already found. They are the backbone of an investigation, but no single investigator needs all of them.

Library Use represents several hours of continuous searching and finds material only if it is there. Getting into a locked rare-book room may still need Persuade, Fast Talk, Charm, Intimidate, Credit Rating, or credentials. Law often gets harder in a foreign jurisdiction unless the investigator has studied that legal system.

The Research Chain

Good investigations often move through a chain: Library Use finds the newspaper archive, History identifies the old expedition, Anthropology explains why a community hides the event, and Occult recognizes that the symbol is not decoration. These skills overlap in theme, but they answer different questions.

That is why a failed knowledge roll should not end a lead. Let another investigator try a different method, or make the failure cost time, privacy, or certainty. A complete list is a reminder that a clue can be approached from more than one direction.

Cthulhu Mythos Is Not a Normal Knowledge Skill

Cthulhu Mythos is on the list because it matters mechanically, not because it is a career choice. It represents the mind opening to things humans should not know. No investigator may start with points in it unless the Keeper agrees, it never receives improvement ticks, and it caps maximum Sanity at 99 minus the skill. It is earned during play, at a cost. The Cthulhu Mythos skill guide covers how it grows.

Social and Status Skills

Social skills work best after the player states their angle, tone, and the outcome they want. "I use Persuade" is incomplete. "I explain that the curator's reputation is at risk unless she lets us see the donor files" gives the Keeper something to judge.

Social rolls need a clear boundary. The Keeper decides what a nonplayer character can reasonably be talked into, and a success achieves the stated goal, not unlimited control. A guard may let an investigator into a records room without becoming a lifelong friend.

Credit Rating deserves attention during character creation. Each occupation sets a range for it, it is bought with skill points, and it never gets improvement ticks. It can also stand in for APP when judging first impressions. Use it to frame access, clothing, introductions, and everyday resources, then play the person who carries that status.

Movement, Stealth, and Survival Skills

These skills turn travel and access into scenes. They matter whenever the group must get somewhere dangerous, unseen, quickly, or alive.

Drive Auto is named for the modern and 1920s eras; the rulebook suggests renaming it for other periods, such as Drive Carriage in Victorian London. Pilot needs a roll on every landing, even in good conditions.

Do Not Let Access Skills Become an All-Purpose Bypass

Stealth gets someone past a guard; it does not say what they do once inside. Disguise gets a person through the front door; it does not supply an explanation for every question. Drive Auto wins a chase; it does not find the destination.

That limit is useful. It creates handoffs between investigators and lets the Keeper make an infiltration about choices instead of a single roll.

Technical, Medical, and Trade Skills

Technical skills give an investigator a non-academic role in an occult case. They also produce concrete evidence: a cut wire, an altered prescription, a mismatched part, a forced lock, or a machine made to do something it should not.

Medicine and First Aid do different jobs. First Aid is urgent intervention; Medicine treatment takes at least an hour and becomes a Hard roll if it is not done the same day as the injury. A patient can receive only one First Aid and one Medicine treatment until they take more damage, except that a dying character may need First Aid more than once. In the 1920s, the rulebook uses Physics and Electrical Repair for the electronics of the day instead of Electronics.

Combat and Physical Skills

Violence is sometimes unavoidable in Call of Cthulhu, but it does not solve the central problem of cosmic horror. These skills help an investigator survive, protect someone, or escape. They do not make anyone invulnerable, and combat rolls cannot be pushed.

Fighting and Firearms specializations each have their own base value:

Fighting (Brawl) covers unarmed fighting plus the clubs, knives, bottles, and chair legs anyone can pick up. Rifle/Shotgun covers any rifle or scattergun, and an assault rifle firing single shots. A detective who carries a handgun and a veteran trained on a rifle have different training stories; write that into the investigator instead of buying a vague combat package. The firearms guide covers weapon choice.

Fields of Study and Specializations

Some skills cover a wide territory and split it into specializations. You buy the named specialization, never the umbrella: Science (Chemistry) or Science (Astronomy), but not "Science." The rule applies to Art and Craft, Fighting, Firearms, Language (Other), Pilot, Science, Survival, and the uncommon Lore skill.

A percentage describes capability in a field within its era, not a share of everything knowable. The rulebook's example is a modern physicist at 60% who knows far more than a 90% physicist from 1910. Location matters too: a Japanese investigator with Law 75% in Japan may face a higher difficulty on a question of Spanish law. A field needs both a subject and a context.

Specialized Skill Categories

Every Science specialization starts at 01% except Mathematics, which starts at 10%. Engineering sits under Science for convenience even though the rulebook notes it is not strictly a science. Neither list is closed: the Keeper can add specializations that fit the era and campaign, as long as the name is precise enough that the table knows what it covers.

Language (Other) has useful benchmarks in the rulebook. At 5% an investigator can identify the language without a roll, at 10% they can communicate simple ideas, at 30% they understand transactional requests, at 50% they are fluent, and at 75% they can pass as a native speaker. One successful roll usually lets a reader understand an entire book. Ancient or alien languages such as Aklo should not be chosen unless the Keeper agrees.

Choose a Specific Specialization

Use this four-part test when choosing a field:

1. Origin: Why does this investigator know it? A degree, trade, hobby, military service, family business, obsession, or prior case can all work.
2. Method: What does the investigator do with this knowledge? Analyze samples, reconstruct events, recognize patterns, translate documents, operate equipment, or make something.
3. Campaign hook: Where is it likely to come up in the campaign's locations, threats, or institutions?
4. Distinct contribution: What question can this investigator answer that nobody else in the group can?

Science (Geology) belongs naturally on a mining engineer, a surveyor, an expedition scholar, or a character whose family money comes from extraction. It dates rock strata, recognizes fossils and minerals, and assesses soils and drilling sites. It is a stronger pick when the campaign includes tunnels, mountains, mines, or suspicious stonework than when the whole campaign is a drawing-room mystery.

You do not need a doctorate for every specialty. The rulebook allows for well-read amateur scientists as well as trained ones. The background should still match the score: a hobbyist may know enough Astronomy to spot an impossible star pattern, while a university astronomer has the rating to work out what it means.

The Best Fields by Investigative Job

No field is best everywhere, but ranking by job helps turn a broad concept into a usable sheet.

These are not hard borders. Biology can help with forensic matter, and Mathematics can support code work. Choose the primary lens first, then ask whether a related skill covers the rest of the investigator's role. For the broader group roles, see the best skills rankings in the Skills Guide.

Science Specializations in Practice

Science specializations make strange evidence concrete. They should not reduce horror to a lab report. They establish what an ordinary explanation would predict, then show why this evidence refuses to cooperate.

Chemistry and Pharmacy

Chemistry covers substances, reactions, and analysis; with it an investigator might create or extract a compound. Pharmacy covers chemical compounds and their effect on living things, including medicines, toxins, and synthesis. Choose Chemistry for a laboratory or industrial background and residue analysis. Choose Pharmacy for a medical or apothecary background, poisoning cases, and drugs.

Both touch toxins. The Keeper may allow the other one at a higher difficulty when the overlap is close, but the distinction should still matter. A chemist may identify an unusual powder; a pharmacist better understands what it does to a patient.

Biology, Botany, and Zoology

Biology is the study of living organisms, including cells, ecology, genetics, microbiology, and physiology. Botany is plant life: classification, growth, disease, and chemical properties, including whether a plant is poisonous, edible, or psychotropic. Zoology covers animals: structure, classification, behavior, and distribution.

These fields shine in rural, expedition, medical, and body-horror games. They also work in a city when the clue is a strange parasite, a greenhouse specimen, an animal attack, or evidence that does not belong in the local ecology.

Forensics

Forensics is the crime-scene field: analyzing and identifying evidence such as fingerprints, hair, and body fluids to establish fact for legal disputes. It suits police, laboratory workers, coroners, technically minded lawyers, and private investigators.

It does not replace every medical or scientific question. A forensic specialist connects physical traces to an event; Medicine treats the person, Biology analyzes living matter, and Chemistry identifies the substance. Let those differences create collaboration.

Astronomy, Mathematics, and Physics

Astronomy tells which stars and planets are overhead at a given time and when eclipses and meteor showers occur. Mathematics handles numbers, logic, and formulae, and the rulebook says it can identify non-Euclidean geometry and help with complex codes. Physics covers pressure, materials, motion, magnetism, electricity, optics, and radioactivity, with some ability to build experimental devices.

This trio suits cosmic horror while staying grounded. The astronomer says a conjunction should not happen for centuries. The mathematician sees that a diagram uses impossible relationships. The physicist shows that an effect could not come from any available machine. None of that tells the group what to do next; it makes the impossible visible.

Cryptography and Engineering

Cryptography is a specialized branch of mathematics for making and breaking codes, which may hide in music, art, or modern computer code as well as writing. Engineering turns scientific findings into machines, structures, and materials. Together with Geology, Engineering makes a strong expedition or industrial pair: one explains why a structure is failing, the other why the land itself is wrong.

Art and Craft, Language, and Survival Specialties

Art and Craft is more than decoration. Photography takes clear pictures, develops them, and can bring out half-hidden detail. Forgery produces convincing fake documents given the right materials and an original to copy; spotting a fake on close inspection is an Appraise roll opposed by the forger's skill. A successful Art and Craft roll can also tell where or when an item was made, or who made it. Choose a craft with an actual practice and tools, and use the base value of 05% for any of them.

Languages matter when tied to places, communities, documents, and a believable biography. Each Language (Other) is its own skill, not a general "foreign languages" rating. Choose one because the campaign gives it a place to matter.

Survival specialties define environments: the rulebook's examples are desert, sea, and arctic. Someone competent in one is not automatically prepared for another, and the Keeper may apply a modifier when an investigator lacks the right specialization. These become central in travel-heavy campaigns.

Fighting and Firearms specializations describe actual practice as well. A capable brawler is not a trained swordsman, and a rifle user is not fluent with every firearm.

Overlap, Substitution, and Difficulty

Specialties overlap, but overlap is not permission to ignore what is on the sheet. When an investigator lacks the obvious discipline, the Keeper may allow an allied specialization if the connection is credible, usually at a higher difficulty. The rulebook names Mathematics and Cryptography, Botany and Biology, and Chemistry and Pharmacy as overlapping pairs.

Its worked example is a numerical code: Cryptography needs a Regular success, so Mathematics in its place needs a Hard one. Pilot works the same way; flying an unfamiliar type of aircraft is possible at increased difficulty. Before proposing a substitute, ask:

• What exact task is the investigator trying to accomplish?
• What knowledge does the chosen specialty share with the obvious one?
• What important part of the task remains outside the investigator's training?
• Would a higher difficulty preserve that difference?

The Keeper has the final call because the setting and evidence decide whether the overlap is real. Players should give a concrete reason rather than pointing out that two scientific words sound related.

Optional Transferable Specializations

The Keeper Rulebook includes an optional transferable skill benefit for Fighting, Firearms, Survival, and languages grouped by family. It is not the default, so ask whether your campaign uses it.

Under that option, the first time an investigator raises one specialization in a group to 50% or more, every other specialization in that group gains 10 points, but not above 50%. It can happen once more: the first time one reaches 90% or more, the others gain another 10 points, capped at 90%. During creation, a player can raise one specialization first and collect the bonus before spending on the others. The rulebook example: raising Fighting (Brawl) to 50% lifts Fighting (Sword) from 20% to 30%. For languages, the bonus applies within a family (Germanic, Slavic, and so on) and never involves Language (Own).

Art and Craft and Science do not use this rule. Their overlap is handled case by case through the Keeper's call on allied fields and difficulty, so do not give Science (Botany) 10 free points because Science (Biology) reached 50%.

Era, Place, and Credibility

Scientific knowledge is limited by the campaign's period, and the rulebook tags some skills as Modern only. A field may have tools, theories, and practical limits very different from today's. The Keeper should establish the setting and technology early. Players should say how their investigator learned the field and what equipment or access they need. When period limits make a task harder, the table should understand why before the roll.

Specialization also creates social credibility. A scholar of ancient languages has a plausible reason to be in a university archive. An engineer can ask focused questions at a factory. A botanist can earn a gardener's attention. A field's value is not only the roll; it is the scenes it makes believable.

Uncommon and Setting-Specific Skills

The Keeper Rulebook lists uncommon skills that are not on the standard investigator sheet. They are valid when the campaign, occupation, or setting supports them, so raise them before character creation.

The Keeper can also add or rename skills for the setting. A historical campaign may swap an anachronistic skill; a far-future game may need new ones. Keep the same principle: a new skill should describe a distinct approach and create decisions, not repackage five existing skills.

Choose Skills for a Real Investigator

Run this quick audit after spending occupation skill points and personal-interest points:

1. Can I explain why this investigator knows each specialty?
2. Do I have one way to find or interpret evidence?
3. Do I have one way to handle people or status?
4. Do I have a practical or physical contribution when the case leaves the study?
5. Does one choice connect to my backstory, a hobby, a relationship, or a prior life?
6. Does another investigator already cover this skill, and is my approach still different?

Overlap is useful. Two researchers can cross-check a lead, two drivers keep a chase alive, and two social investigators can play good cop and bad cop. The goal is not perfect coverage but a group with several ways to learn, enter, persuade, survive, and make mistakes.

Playing a Specialist

Pick one or two fields you can portray with confidence, then learn enough real-world texture to ask vivid questions. You do not need a chemistry degree to play a chemist, but you should know whether your investigator is looking for residue, a reaction, contamination, or a way to test a theory.

When you want to use an allied specialty, explain the link in the fiction. "My biology training includes microscopy; can I tell whether this tissue is plant or animal?" is a useful request. "I have a science, so I know it" is not. A good field of study opens the investigation for the group instead of monopolizing it.

Specialization Checklist

• The specialization has a precise name and a credible place in the investigator's background.
• You can describe the evidence, question, or method it brings to a scene.
• The campaign gives it at least one plausible way to matter.
• The group has other skills that can act on what the field finds.
• You know where an allied specialty might overlap and where it should not.
• You have asked whether the optional transferable skill rule is in use.

Keeper Reference

When a player reaches for a skill, ask before deciding the roll:

• What is the actual goal, and what does success change?
• Does this skill describe the method, or does another fit better?
• Is the task routine enough that no roll is needed?
• Could another investigator reach the same information through a different skill and scene?
• Does a specialization really overlap, and should that raise the difficulty?
• What concrete complication follows an ordinary failure?

For specialists, ask for the intended result before choosing the skill. Someone examining an unknown liquid may want to identify it, learn whether it is poison, connect it to a body, or reproduce it, and each goal points to a different field. Reward a specialist with a specific observation rather than a complete solution: the botanist's impossible growth cycle, the engineer's reason the elevator is unsafe, the cryptographer's method for continuing the work. Then let the group decide what to do.

Support reasonable overlap, but protect expertise. A higher difficulty is usually enough to let a clever allied skill help without erasing the reason another player bought the dedicated specialty. Decide on the optional transferable rule before it comes up, and apply it consistently.

The complete skills list works when it invites more approaches to the same mystery. Let skills show personality and method, let the dice settle tension, and keep the clue alive even when the first plan fails.

Related Guides

• Call of Cthulhu 7e Skills Guide
• Call of Cthulhu 7e Character Creation
• Call of Cthulhu 7e Occupations
• Call of Cthulhu 7e Backstory Guide