From the Back of the Book:
"What if everyone around you were a doppelganger... and only you didn't know?
The Complete Guide to Doppelgangers is a stand-alone, world-neutral sourcebook covering everything you ever wanted to know about doppelgangers. It includes:
- The true origin of these bizarre creatures.
- Background on doppelganger social structure, including their various life stages and their relationship to mimics.
- Details on how the doppelgangers have penetrated human society.
- New feats and skills for doppelgangers, plus the dreaded Protean Warrior class.
- Unique campaign ideas centered around doppelgangers.
- New monster stats for intriguing variations on the standard doppelganger.
- Supplemental material online."