A full and complete RPG construction kit that can construct damn near any genre, any characters, any powers, any equipment, etc. you can build whole world's with what's in this PDF. it has rules to create vehicles, weapons, superpowers, magic, etc. you can run any genre with a little effort.
there's a really revolutionary new turn system that's unlike anything I've even heard of. it combines faster play with gritty, detailed combat in a truly ingenious new way.
this book does what gurps and hero system claim to at a fraction of the cost.
get the quickstart to explore the new combat system, and if you like it get the whole thing