What is Pathfinder?
Pathfinder is a rich and complex fantasy RPG that uses the same d20 ruleset at the core of Dungeons & Dragons. Players take on the role of heroic adventurers who travel the world solving problems, unravelling mysteries and collecting treasure. Characters in Pathfinder are highly customizable and become more complex the longer you play, presenting players with escalating challenges as they must come up with the best ways to use their abilities to fight progressively more dangerous foes.
There are many facets in Pathfinder that separates itself from other systems but the biggest change is the three-action system, a new way of codifying what characters can do on their turns.
The modularity of the system makes it easy to customize characters to design them in practically any way you'd like them to play, allowing a great deal of roleplay and mechanical value to the gameplay experience.