Roll d100 equal to or under your skill percentage. Success tiers at half (Hard) and one-fifth (Extreme) of the skill value. Bonus and penalty dice adjust the tens digit. Failed rolls can be pushed for a second attempt at greater risk.
Best For
Investigation-driven horror where combat is deadly and sanity is fragile. Great for one-shots.
Highlights
Tracking Sanity as a depletable score ties mental erosion to the fiction, so confronting cosmic horror mechanically wears characters down. The percentile skills resolve on a d100 roll-under, with Hard and Extreme bands at half and one-fifth of the rating. Bouts of Madness convert failed Sanity checks into temporary phobias, manias, or loss of character control.
Considerations
The chase rules add a detailed positioning subsystem whose complexity outweighs how often it sees use. Character creation allocates points across a long list of skills, a slow first step for new players. In long campaigns the sanity spiral can strip a character of player control as madness accumulates.