From the back of the book:
STILL MORE RULES!
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. The HERO System Advanced Player’s Guide expands on those rules, offering more information and options for dedicated HERO System gamers.
But if even that’s not enough for you, The HERO System Advanced Player’s Guide II contains even more new rules, optional and variant rules, and rules expansions for your HERO System games! It includes:
rules for resolving Skill use like combat, and for changing combat to work like the Skill system
new Powers including Extradimensional Space, Object Creation, Probability Alteration, Replay, and Time Stop
Social Combat rules and guidelines, including three sample systems ready for use in any campaign
expanded Focus creation rules
With the Advanced Player’s Guide II, it’s even more fun to Be A Hero!