According to the ad in the back of my (pre-Palladium-intervention! 
I didn't know this made it more valuable) copy of TPO, there were to be four follow-ups: Pawns: The Opening Move, Knights: Strategies in Motion, Bishops: The Eternal Crusade, and Chessboards: Planes in Contention. Now, my copy of Chessboards is subtitled "Planes of Possibility" rather than "Planes in Contention," but Pawns didn't change title before release (or at least not before I got my copy). I don't recall ever seeing a copy of Bishops or Knights, though. Obviously Knights exists, since el-remmen has seen it, but has anybody ever seen Bishops?
As for the basic mechanical premise, it postulates that the difference between deities and mortals is that there is a mystery energy called "Primal" which is the essence of godhood. Deities have it, mortals don't- so to make your mortal character into a god, all you have to do (yeah, right![:]](http://www.enworld.org/forum/images/smilies/devious.png "Devious :]")
) is get him some Primal. The book then goes on to discuss what you can do with this stuff, such as blasting things (a "Wrath-of-God" type attack), shielding things (Rock beats Scissors and Scissors beats Paper, but Primal beats Everything), and various other effects. It explains how deities acquire it, what they do to get more of it (hint: religions are best), and how they tie themselves to planes and various aspects of reality (i.e. get portfolios/spheres of influence) with it.
In other words, it presents a complete system for role-playing gods, whether you want to have divine PCs or whether you just want to have a way to figure out what happens when your mortal PCs manage to teleport into Set's throne room (the example given in the book's introduction). And the system presented is in effect a meta-system that can be reinterpreted into game statistics for any game system- the appendix in the back of the book gives conversion notes for most or all of the major RP systems of the time.
I didn't know this made it more valuable) copy of TPO, there were to be four follow-ups: Pawns: The Opening Move, Knights: Strategies in Motion, Bishops: The Eternal Crusade, and Chessboards: Planes in Contention. Now, my copy of Chessboards is subtitled "Planes of Possibility" rather than "Planes in Contention," but Pawns didn't change title before release (or at least not before I got my copy). I don't recall ever seeing a copy of Bishops or Knights, though. Obviously Knights exists, since el-remmen has seen it, but has anybody ever seen Bishops?As for the basic mechanical premise, it postulates that the difference between deities and mortals is that there is a mystery energy called "Primal" which is the essence of godhood. Deities have it, mortals don't- so to make your mortal character into a god, all you have to do (yeah, right
) is get him some Primal. The book then goes on to discuss what you can do with this stuff, such as blasting things (a "Wrath-of-God" type attack), shielding things (Rock beats Scissors and Scissors beats Paper, but Primal beats Everything), and various other effects. It explains how deities acquire it, what they do to get more of it (hint: religions are best), and how they tie themselves to planes and various aspects of reality (i.e. get portfolios/spheres of influence) with it.In other words, it presents a complete system for role-playing gods, whether you want to have divine PCs or whether you just want to have a way to figure out what happens when your mortal PCs manage to teleport into Set's throne room (the example given in the book's introduction). And the system presented is in effect a meta-system that can be reinterpreted into game statistics for any game system- the appendix in the back of the book gives conversion notes for most or all of the major RP systems of the time.
