This supplement introduces a magical substance called incarnum into the D&D game. With this book, the players characters can meld incarnum the power of souls living, dead, and unborn into magical items and even their own bodies, granting them special attacks, defenses, and other abilities (much as magic items and spells do). Incarnum can be shaped and reshaped into new forms, giving characters tremendous versatility in the dungeon and on any battlefield.This book also features new classes, prestige classes, feats, and other options for characters wishing to explore the secrets of incarnum, as well as rules and advice for including incarnum in a D&D campaign.