Rules reference

Combat in Call of Cthulhu 7th Edition

Turn flow, actions, and common combat rules. 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.

Key points

Combat rules matter most when they keep scenes moving. This page focuses on decision points and the system’s core resolution loop.

Copyable 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
Roll loop reminder

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.
Example: Spot Hidden 55%: a roll of 42 succeeds; a harder threshold would require a lower roll.
Examples
Example: Declare intent, not just an action

Instead of “I attack,” state the goal: “I push them back from the door” or “I buy time for the escape.” This makes outcomes clearer.

Example: End scenes early

Once the winner is clear, wrap it. Don’t grind out the last 10% if it doesn’t change the story.

Common mistakes (smallest fix)
  • Mistake: Unclear turns and slow decisions. Fix: State intent, pick one action, resolve fast, and move on.
  • Mistake: Grinding after the outcome is obvious. Fix: End scenes early and narrate the final advantage.
Character creation
Step-by-step checklist.
Cheat sheets
Quick lookup while you play.

Call of Cthulhu 7th Edition FAQ

How does the percentile system work in Call of Cthulhu?
How does the skill improvement system work?
What are the Characteristics in Call of Cthulhu 7e?
How does Sanity work in Call of Cthulhu?
What are Occupations in Call of Cthulhu?

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