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.
- 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
- During play: mark skills you used.
- After session: roll to improve marked skills.
- Track Sanity impact as part of progression pressure.
After the session, roll to improve the skills you actually used. Your investigator gets better where the story pushed them.
Progress isn’t only skills: track Sanity consequences and long-term effects as part of the campaign’s arc.
- 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.