Call of Cthulhu 7th Edition
How to play Call of Cthulhu 7th Edition
A fast, practical overview. Call of Cthulhu 7th Edition is a horror investigation roleplaying game based on H.P. Lovecraft's Cthulhu Mythos. Players take on the roles of Investigators, ordinary people who uncover cosmic horrors beyond human comprehension. As you investigate mysteries, your character's Sanity slowly erodes, skills improve through use, and the line between reality and madness blurs.
Beginner checklist
Describe what you try to do (then pick the most relevant skill).
Roll d100 and try to roll under your skill.
Use difficulty bands (Regular/Hard/Extreme) to set stakes.
Track Sanity and consequences; failing forward is normal in investigation play.
How rolls work
Call of Cthulhu uses percentile skills: roll d100 and succeed if you roll at or under your skill. Difficulty often shifts the threshold (Regular/Hard/Extreme) and Sanity loss is a core pressure loop.
Pick the relevant skill (e.g., Spot Hidden, Library Use).
Roll d100 and compare to your skill rating (and difficulty threshold).
Apply consequences: information gained, complications, or Sanity loss when appropriate.
Spot Hidden 55%: a roll of 42 succeeds; a harder threshold would require a lower roll.
Key facts
Percentile skill system: Roll d100, succeed if equal to or below skill rating
8 Characteristics: STR, CON, POW, DEX, APP, SIZ, INT, EDU
Occupation system: Each occupation grants skill bonuses and Credit Rating range
Sanity mechanics: Starts at 99-POW, decreases with Mythos encounters
Skill improvement: Mark skills during play, improve after sessions
Derived stats: HP, Sanity, MP, Build, Damage Bonus calculated from Characteristics
Derived stats: HP, MP, Sanity, Build, MoveRate, DamageBonus
Play examples
Spot Hidden under pressure
You search a room fast before the cult returns. Roll Spot Hidden; a Regular success finds the clue, a failure still finds something but costs time or adds a complication.
Hard/Extreme as stakes
If the clue is tiny or conditions are bad, the Keeper can call for Hard/Extreme. You're not changing the scene, just raising the required quality of success.
Common mistakes
Treating failures as 'nothing happens'.
Fail forward: you still get info, but pay with time, noise, or Sanity pressure.
Forgetting difficulty bands (Regular/Hard/Extreme).
Use them to express stakes without changing the whole scene.
Character creation
Choose Occupation
Roll 3d6×5 for STR, CON, POW, DEX, APP (range 15-90). Roll (2d6+6)×5 for SIZ, INT, EDU (range 40-90).
Calculate Derived Stats: HP, MP, Sanity, Build, Magic Points
Distribute Skill Points based on Occupation
Choose Personal Details and Background
Select Equipment and Spells
What to track during play
What to open next
Prefer definitions? Browse terms in the Call of Cthulhu 7th Edition glossary.
FAQ
How does the percentile system work in Call of Cthulhu?
Call of Cthulhu uses a d100 (percentile) system. Each skill has a rating from 0-100. To attempt a skill, roll d100. If you roll equal to or below your skill rating, you succeed. Rolling 1-5 is an extreme success (hard difficulty), and rolling exactly your skill rating is a critical success.
How does the skill improvement system work?
During play, mark skills when you attempt them (whether you succeed or fail). After each session, you can try to improve marked skills. Roll d100. If the result is higher than your current skill rating, you gain 1d10 skill points. This represents learning through experience, a core mechanic of Call of Cthulhu.
What are the Characteristics in Call of Cthulhu 7e?
Call of Cthulhu uses eight Characteristics: Strength (STR), Constitution (CON), Power (POW), Dexterity (DEX), Appearance (APP), Size (SIZ), Intelligence (INT), and Education (EDU). Most are rolled with 3d6×5, while INT and EDU use (2d6+6)×5. These determine your derived stats like HP, MP, and Sanity.
How does Sanity work in Call of Cthulhu?
Sanity starts at 99 minus your POW characteristic. As you encounter Mythos horrors, you lose Sanity points. When Sanity drops to certain thresholds (like 50 or 20), you gain mental disorders. Temporary insanity occurs when you lose 5+ Sanity in one session. Sanity represents your grip on reality. Lose too much and you become permanently insane.
What are Occupations in Call of Cthulhu?
Occupations define your Investigator's profession and provide skill bonuses. Each occupation has a Credit Rating range (wealth level) and specific skills it improves. Examples include Antiquarian, Doctor, Journalist, Private Investigator, and Professor. Your Occupation Points (EDU×4) must be spent on occupation skills.