A few RPGs have used opposing stat pairs before. Cthulhu with Sanity and Mythos, a gain for one is a loss for the other. Or the Shock version being something like Love / Hate in a pair.

And lots of games have shifting stats. WOD with its temporary and permanent Willpower, Glamour, Banality, etc which are mostly treated like resources, but sometimes also rolled. The recent Masks PBTA game has made shifting stats one of the center pieces of its design.

But I'm curious if any games, especially PBTA games have combined the two. Specifically an opposing pair of stats that shift based on play.

For example, if you were to do a PBTA back for Changeling the Dreaming, an obvious opposing pair would be Banality vs Glamour. Some moves would use Banality, other moves Glamour. But you can't have a high stat in both. Say a range of 3-0-3. Where a +3 to one would be a -3 to be other. During play and by making certain moves (or failing certain moves) you can shift that bonus one step at a time in either direction, but capped at +3. A score of zero would be balanced.

So...

Banality <-> Glamour
+3 +2 +1 0 +1 +2 +3

You start with a +2 in Glamour which is functionally equivalent to a -2 in Banality. So Glamour moves are easier, but Banality moves are harder. You roll a 6- on a Glamour move and your stat could shift down (Banality goes up), conversely when you succeed on a Glamour move your Glamour could shift up (Banality goes down). The reverse is also true. Banality makes you resistant to magic, Glamour helps you use magic. So their both desirable, though possibly not the greatest example.

My initial thought was 3-4 of these pairs as the stats for a hack. Possibly a Changeling game, but not necessarily. I think it could generally work in a lot of ways.

Is this something that's been done before? If so, by whom? If not, does that sound like it would be an interesting mechanic at the table?

I think the whole document would read better without the GM Moves part.

Okay, so you're suggesting I remove the GM moves section entirely, got it.

You don't really go into detail enough about what Soft Moves and Hard Moves are for that part to be worth anything, and most of what you want to say there is already covered in your description under "Actions".  That's really where you want attention focused. 

The GM Moves section offers decent advice for someone who already knows what those two things are, but doesn't explain them very well.  (I think a couple examples would help.)  It's probably better just to omit that whole section rather than confuse people.

Okay, so you're also suggesting I expand the GM moves section and include examples... er, got it.

Other than that, it seems clear, concise, and playable.  The only ambiguity I see is that story points change a 6- roll to a 7-9 roll before the dice are rolled which 1) is a temporal paradox, and 2) doesn't describe what happens to the story point if you do not roll a 6-.  So even though its not hard to understand, that section could use a little bit of editing.

Thanks for the feedback.