Beginner quickstart
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.
Quick answer
You describe actions, the table uses the system's core resolution mechanic when the outcome is uncertain, and the GM applies outcomes to keep the story moving.
- 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.
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.
- 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 in this system: HP, Sanity, MP, Build, DamageBonus, MoveRate
Examples (success, failure, edge cases)
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.
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 (and the smallest fix)
- Mistake: Treating failures as 'nothing happens'. Fix: Fail forward: you still get info, but pay with time, noise, or Sanity pressure.
- Mistake: Forgetting difficulty bands (Regular/Hard/Extreme). Fix: Use them to express stakes without changing the whole scene.
Character creation (what to decide)
- Choose name, concept, nationality, residence, background.
- Generate Characteristics (random or point allocation).
- Compute Derived stats (HP, Sanity, MP, Build, Damage Bonus, Move).
- Select Occupation, note Credit Rating range.
- Calculate Skill Points: Occupation Points = EDU×4; Personal Interest Points = INT×2.
- Spend Skill Points (respect base chances and caps).
- Pick backstory details (Traits, Ideology/Beliefs, Significant People, Meaningful Locations, Treasured Possessions, Injuries/Scars, Phobias/Manias, Arcane Tomes/Spells/Artifacts).
- Buy equipment/cash within Credit Rating and starting cash rules.
- Keeper reviews; adjust for Age effects if used.
What to track during play
- Sanity
- Hit points
- Luck (if your table uses it)
- Key skills used (for improvement checks)
What to open next
FAQ
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.
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.
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.
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.
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.