Mind over Matter is a book written for old-school versions of the world's most popular role-playing game. It includes: - Two versions of psionics, one the traditional system of disciplines and devotions, but using activation rolls instead of psionic points, and the other based on the rules from Tome of Battle: Book of Nine Swords.. - Twelve psionic classes, including battlemaster, luck thief, psi-warrior, and more. - Rules on adapting existing magical items to psionic ones as well as creating new psionic items. - Rules on creating new psionic monsters and a dozen examples. While written for OSR-games, the contents in this book can be easily adaped to other games, as well.