There are kind of two say yes-s: there's "say yes when the players establish something about the world" and "say yes or roll the dice when the players attempt to do something."
The neat process that Sage encapsulates is that until something is narrated into the game, its just a 'possibility'. Sure, your prep may include impending dooms that carry on regardless and dungeons that you have created as locations, but intentionally the details
and the action
emerge through play.
I think tangentially, the whole idea of saying yes being hard baked into the principles and moves paradigm illustrates the design philosophy of 'fiction first'. The conversation is what matters. There is no 'tactical mini-game', 'take 10/20', 'skill challenge', 'Duel of Wits'. There is just talk between the players and some dice rolling when the moves kick in.
In my play, the players (that includes the GM) are establishing something about the world when they engage the fiction with such 'cue-specific' moves such as Hack 'n Slash
or Defy Danger
. What moves you use in reply as GM simply reflect on your chosen play-style and how much player agency you are comfortable with. Make no-mistake, the whole game is about playing to see what happens.
I think its worth mentioning Dan, that its not so much a conscious 'say Yes' moment in the example you describe with the thief and Detect Traps
, but as Sage wonderfully illustrates, its a genuine means of player authorship, of validating the flags they wave at you, of engaging with hooks that are created - by the group - in the conversation as it happens (not part of some long convoluted prep process covering every possible fictional eventuality).
This process is what begins the 'move snowball'. Its a trigger
, not just of that specific move, but a whole undetermined thread of potential player and GM moves to follow. You have to be willing to let the players engage. Seeing it as a means to introduce 'impressions' and musing on the possibility that they'll run with it. Just saying 'nope, no danger here, no need to detect traps
', circumnavigates the whole mechanical interface of moves/intent/situation of playing to see what happens.
Now this choice to say 'no need to roll' may be entirely appropriate considering the shared situational space, but its not about saying Yes or rolling. Its about whether you want to let this move open the rabbit hole and see just how deep it is. I love
taking the red pill and staying in wonderland almost every time. Its what I love about this game :)