A live-action fantasy role-playing system that's been around since 1981. Currently on its seventh edition.
from a duplicate entry
From back of rule book
The International Fantasy Gaming Society (IFGS)is a non profit organization created to design and run live scale outdoor fantasy games. Our system includes eight character classes and has mechanisms for fighting (with mock, padded weapons) and for casting spells.
From the web site
IFGS has a class-based Fantasy Rules system that has evolved over a 25 year period that will soon see the publication of its 7th edition. Our games generate experience points for the participants, who may spend those points to develop characters within the class system. Characters continue from game to game, sometimes traveling from world to world as their owners visit other IFGS Chapters. Chapter and National Registries keep track of these characters and their possessions and experiences.
IFGS games are played in a variety of settings with full-size foam weapons, mock armor, and costumes. In an IFGS game, you have the opportunity to become a different person. The creativity and imagination you pour into your characters is what helps to make the game so much fun for you!
Creating a character begins with your imagination.