Pathfinder
A variant of the 3.5th edition of D&D¸ published under the Open Gaming License. It consolidated and simplified skills and changes certain rules features such as how favored class and class skills worked¸ but it is intended to be compatible with supplements and adventures designed for 3.5th edition. - A description from https://darkshire.net/jhkim/rpg/encyclopedia/ with kind permission of John H. Kim