Pathfinder RPG: Occult Adventures - Rules of Play says:
There is an unseen world all around you. On the streets and in the halls of power, in your dreams and across the bizarre planes of the multiverse, there are those who walk among us like giants among ants, twisting reality to their wills in their search for ancient knowledge. Now pull back the curtain of the mundane world and learn the secrets of these occult masters—if you dare!
Pathfinder RPG Occult Adventures is an indispensable companion to the Pathfinder RPG Core Rulebook. This imaginative tabletop game builds upon over 15 years of system development and an Open Playtest featuring more than 50,000 gamers to create a cutting-edge RPG experience that brings the all-time best-selling set of fantasy rules into a new era.