I was listening to a recent episode of Push the Roll, where after a series of exceptionally bad dice rolls, the plucky post-apocalyptic racoon junkyard society was faced with an outbreak of fire. One player asked if the raccoons had any sort of fire sprinkler system. The story had gone so far from expectations that even in this highly improvisational gameplay, the GM hesitated for just a moment and that's when I had an idea.
I think in moments of indecision, the setting or theme or tone of a story could be called on to suggest a way forward. To return to the example, we had a complex story underway with multiple themes present. There was the overarching dread of the Call of Cthulhu system they were playing, there was the whimsy of the raccoon story their were telling, and there was the gritty post-apocalyptic setting (to name just a few). Imagine a Tone Table that the players had filled out at the onset of play, 1-40 = Dread, 41-60 = Whimsy, 61-80 = Gritty, etc. In moments of uncertainty, a simple die roll can show the story which way to go. Rather than a positive/negative valence, these results would provide a qualitative flavor.
Like PtR, my game strives to be improvisational. I really try to emphasize Contribute But Not Control, meaning no one can expect to have control over where the story is going. Ideally, my game is played GMless, so that also contributes to the usefulness of these Tone Tables.
I assume something like this already exists in some system that I've either not played or forgotten about. Where can I find more like this?