WISH 73: Player Driven Shifts

Ginger asks:
What�s the biggest PC-driven shift you�ve ever experienced in a campaign? If you were a player, what made you feel like you could successfully change the GM�s world? If you were a GM, was this planned or something the PCs surprised you with?

I’ll go with Jim Groves, and Jayson. I am sure I mentioned this before, on Wish 66.
Very early on, Jayson changed a significant feature of the plot of my game, at least as I had mapped it out in my mind. And added a whole new strain in the process.
On his way to Amber, from his mother (Sand)’s shadow, Jayson got an unexpected trump call, a desperate one, from Deirdre. Contact brief, mysterious, fraught with peril and the mystery.
Now instead of rehashing what did happen, since I’ve mentioned it before, I am going to tell you what I thought would happen.
Jayson goes to Amber, and parlays the information. In the meantime, Deirdre and Brand wind up in the void between universes, and, eventually, way down the line, they finally escape, but not without cost to either of them. (I was musing which one of them to kill off, or to have the PCs find both bodies…)
I didn’t intend Brand to be a subplot for years in the game, and Jayson shifted that. As a result, the whole Apollo subplot came into focus, and the foiled attempt by Brand to take the Fount (Bhangbadea and company staving off Brand in a dramatic battle!)
As a player, I could be wrong, but I don’t think I’ve really shifted a GM’s world that strongly. It also hurts that I’ve rarely had characters around long enough to really do that, over time. In fact, until GA, the only active characters I had, period, were Marcus and Cadmus.
It does explain why I don’t think I’m that good of a player. I simply don’t have the “chops” most of the people in my circle have.