Rules reference
Conditions in Call of Cthulhu 7th Edition
Status effects and how they impact characters and play. 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
Conditions define mechanical states that alter what a character can do. Use this page to quickly understand the most common effects and how to resolve them.
- 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
When a condition is applied, note the source and duration. At the start of each turn (or scene), check which conditions expire or escalate.
Some systems let conditions stack; others replace. Check your system’s rules for which takes precedence when multiple effects overlap.
- Mistake: Forgetting to clear expired conditions. Fix: Check condition durations at the start of each turn or scene.
- Mistake: Treating conditions as flavor only. Fix: Apply the mechanical penalty or restriction every time it's relevant.