Pathfinder : core rulebook

Summary: The Pathfinder Roleplaying Game is a fantasy role-playing game (RPG) that was first published in 2009 by Paizo Publishing, extending and modifying the System Reference Document (SRD) based on the revised 3rd edition Dungeons & Dragons (D&D) published by Wizards of the Coast under the Open Game License (OGL) and is intended to be backward-compatible with that edition. A new version of the game, Pathfinder 2nd Edition released in August 2019 continued to use the OGL and SRD, but significant revisions to the core rules made the new edition incompatible with content from either Pathfinder 1st Edition or any edition of D&D. Starting in 2023, the game instead uses the Open RPG Creative (ORC) license, though it remains backwards-compatible with the existing OGL-licensed Second Edition rules. Pathfinder is supported by the official Pathfinder periodicals and various third-party content created to be compatible with the game.--Wikipedia. <https://en.wikipedia.org/wiki/Pathfinder_Roleplaying_Game>