Universal ● Lightweight ● Free
From the introduction:
PIE is a universal, lightweight and free role playing game with a focus on enjoyment and storytelling. If wanted, it can also turn into a set of advanced rules, suitable for every need. PIE loves fully developed characters and uses pie charts as character sheet to display player characters. A pie chart is easily readable and looks awesome on paper.
The game mechanic is focused on the innovative and peculiar method of defining and understanding characters.