From the Designer's Website:
Les héros de l'ombre font face aux démons...
User Translation from French:
The heroes of the shadow face up against the demons...
Characters have 20 points to distribute between three attributes: vice (vice, used for social actions), crime (crime, used for physical actions), folie (folly, used for mental actions). Each attribute can have a maximum value of 10. They also select two of these attributes either to be at a supernatural level or to become pure (vice becomes vertu (virtue), crime becomes loi (law), folie becomes sagesse (wisdom)). An attribute may be both supernatural and pure.
Task resolution is performed by rolling a ten-sided die, adding the appropriate attribute value, and comparing against a difficulty level or opposed roll. If the die roll is 10 then the attribute value is effectively doubled for this action. Each supernatural attribute grants a character one extraordinary powers (more may be purchased with experience). Pure attributes always resist supernatural powers.