Most fantasy books fall right into the mold. One in particular is a little known series called The Runelords. In that series, people can take the attributes of other people into themselves to become more powerful (strength, wit, grace, metabolism [which adds to your speed and slows down the world from your perspective], beauty, voice [one character can bring down entire castles just by finding the right pitch with his voice], etc.). You gain the attributes, they lose them (this is usually done to strengthen a warrior to fight for a cause in exchange for safety or money). If the people you take the attributes from die, you lose the attribute. Think of how those mechanics could be handled in a video game! --- I stand in the place bathed in heavenly light, thou art where the gate to the Underworld opens, come forth, divine lightning! This is the end! Indignation!