Rules reference

Advancement in Call of Cthulhu 7th Edition

How progression works and how to track it. 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

Call of Cthulhu advancement is a loop: use skills → mark them → roll to improve after sessions.

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
Advancement workflow
  • During play: mark skills you used.
  • After session: roll to improve marked skills.
  • Track Sanity impact as part of progression pressure.
Examples
Example: Improve what you used

After the session, roll to improve the skills you actually used. Your investigator gets better where the story pushed them.

Example: Sanity as progression pressure

Progress isn’t only skills: track Sanity consequences and long-term effects as part of the campaign’s arc.

Common mistakes (smallest fix)
  • Mistake: XP drift (nobody remembers what changed). Fix: Record gains/spends right after sessions and keep a short history.
  • Mistake: Buying upgrades that don’t show up in play. Fix: Spend toward your concept and the scenes you actually get.

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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