When it comes to supplement books to the Dungeon & Dragons game, players and Dungeon Masters alike must learn to pick and choose their battles. I say this because while many D&D books can prove to be quite viable in introducing new material into the game (e.g., new spells, character feats and options, monsters, and adventures), others can be a tad redundant and perhaps even useless to a given campaign. Luckily, Magic of Incarnum--released back in the September of 2005--is of the former eventually and not of the latter, as the idea it introduces into the core D&D game is one that neither TSR, Inc., nor Wizards of the Coast had ever tried before until this past year.
See, Incarnum is the soul energy that manifests itself within living beings. Anyone and everyone who either lives in the present, has ever lived in the past, and will soon be born in the future has a touch of this substance within them, although certain beings are more blessed by and intuitive about it than others are. The human-born azurin, for instance--one of the four races introduced in Magic of Incarnum--are especially aware of that which composes their very essence and utilize it in their careers as adventurers, aiming to either right the wrongs of the material world or subjugate the masses to their will to fulfill more malignant objectives. Similarly, there are the wild, gray-skinned dusklings, whose ties to incarnum blesses them with an innate knowledge about it and the knack for manipulating the energy of their spirits in an effort to mimic the powers of mystic beasts via the Totemist Character Class. The final two races presented in this manual--namely, the rilkans and the skarns--are offshoots of an ancient reptilian race called the mishtai that, when they existed, aimed at attaining "perfection of form" via a philosophy that espouses both physical and mental discipline and development as well as the use of incarnum. Unfortunately, the mishtai failed in this well-meaning yet lofty goal of theirs and eventually became extinct, hence spawning these two peoples and the bitterness they have toward one another as the result of the polar opposition of their general personalities (the nimble rilkans being friendly, outgoing, and daring and the skarns being studious, strictly disciplined, and somewhat scornful of those races they think are beneath them).
More important than the new races, however, are the three Character Classes this book introduces, all of which allow participants to utilize incarnum to aid them in their adventures within their home realm. The aforementioned Totemist, for instance, uses incarnum to forge different artifacts of magical power called Soul Melds that enable her to mimic the properties of the many magical beasts that populate the typical D&D world, from unicorns and blink dogs to manticores and chimera. The Soulborn, in contrast, uses his inner soul energy to bolster his martial prowess and smite those who oppose his moral philosophy, which can be noble or wicked in nature. Finally, the incarnate--the book's focal Character Class--is the very embodiment of law, chaos, good, or evil for her people and is the most adept of the three Classes in using incarnum to form Soul Melds that bolster her fighting skill, rend her foes asunder, or aid her and her fellow adventurers in various other ways. There are also plenty of Prestige Classes for PCs to attain once they reach higher levels, such as the noble Incandescent Champion, the arcane Soulcaster, the mage-hunting Witchborn Binder, and the sinister Necrocarnate. Throw in fifteen keen new monsters, numerous spells and psionic powers for magic- and psionics-wielding PCs (including the Incarnum domain for clerics), a full list of Soul Melds for incarnum-wielding characters, numerous additional feats for PCs and NPCs alike, and three campaign adventures centered around the presence of incarnum, and you've got one impressive book.
To summarize, while there exists the occasional Dungeons & Dragon supplement that just doesn't live up to its potential, there also exists that one manual that proves its worth within every page. Such is what Magic of Incarnum is in its success to provide D&D players with a new take on their favorite pencil-and-paper role-playing game. Indeed, it's the one book by Wizards of the Coast that gets one thinking in more ways than one, which is precisely what an RPG supplement is supposed to do. If you can find this manual, grab it. It's worth every penny!