The HERO System 6th Edition contains all the rules you need to create any sort of character, power, gadget, spell, vehicle, monster, or weapon you can think of.
But sometimes a few more rules can make your job easier, or open up possibilities for your character that you hadn't considered. If you're interested in ways to expand the HERO System, or to change it to suit particular campaigns or play styles, The HERO System Advanced Player's Guide is the book for you. It's filled with advanced, expanded, optional, and variant rules for nearly every aspect of the HERO System. It features new powers, skills, Combat Maneuvers, and other game elements; alternate ways to use specific game elements or build specific abilities; and more details to help players and GMs use the hero rules.