Magic Pants vs. Power Squid! (2009)

An Amazing SuperHero RPG

From the introduction to the book:

It’s the Pants!
Did you ever wonder why superheroes wear their underwear on the outside? Are they in too much of a hurry to dress properly? Or maybe they’re confident enough to be flashy? The truth is that their underwear is the secret of their power. A mysterious individual, known only as Keeton, has discovered how to make what he calls Magic Pants. They give the wearer powers beyond what normal people could achieve otherwise. He has also learned how to make masks, capes, and shoes, but every super hero needs Magic Pants. He gives these items to a select few willing to take up the fight against evil and those who try to tear down society. In this game, you are one of those lucky few.