I think this sort of design will tend to have the consequence that Baker describes
here:
You need to have a system by which scenes start and stop. The rawest solution is to do it by group consensus: anybody moved to can suggest a scene or suggest that a scene be over, and it's up to the group to act on the suggestion or not. You don't need a final authority beyond the players' collective will.
You need to have a system whereby narration becomes in-game truth. That is, when somebody suggests something to happen or something to be so, does it or doesn't it? Is it or isn't it? Again the rawest solution is group consensus, with suggestions made by whoever's moved and then taken up or let fall according to the group's interest.
You need to have orchestrated conflict, and there's the tricky bit. GMs are very good at orchestrating conflict, and it's hard to see a rawer solution. My game Before the Flood handles the first two needs ably but makes no provision at all for this third. What you get is listless, aimless, dull play with no sustained conflict and no meaning.
Good RPGing needs conflict, which can't be resolved simply through "assertion" or via free cooperation/consensus.
Emphasis mine, but bottom line I agree with your (and Baker's) point here. "The right participant said it, at an appropriate moment" isn't enough. We can also want "things that no vigorous creative agreement would ever create". A traditional approach to conflict is the set piece - we've arrived at the place where there is conflict. There might be a veneer of explanation for such conflict, but it's not
driven by play... it's encountered. A hard job in game design is designing the preconditions and mechanisms for satisfying conflict to emerge in play.
It's one reason I think that both Baker and Crane chose to include a large dose of PvP in their sessions of How We Role: players are great at translating their competing objectives into conflict. But not everyone enjoys PvP. Another common mechanism is to give players a game asset that can only be protected and advanced through conflict. BitD externalises that from individual characters - "the crew is the central figure in the stories we’re going to tell about the underworld of Doskvol. Scoundrels will come and go—burned out due to trauma, or killed, or forever lost to their vices, or, if they’re very lucky, gone to some comfortable retirement—but the crew carries on." It's a neat piece of design, and you can see how once players buy into the faction game, player character pursuit of rep and turf yields conflicts.
@FrogReaver said
the kinds of games I want to see designed - ones where participant assertions are the norm and negotiation is minimized
I feel like in truth we shouldn't be thinking - I would like our playful conversation to be mostly assertion or mostly negotiation. Those are instrumental, they're not an ends in themselves. Think about this question
In your game, the game you're actually playing, a) in which stage does invention happen, and b) in which stage does meaning happen?
There's no objectively right or wrong answer, but it's worth thinking about the following observation
A game where the meaning happens mostly pre-play is one in which somebody or everybody has something to say and already knows what it is when the game starts. You can always tell these games: the GM expects his or her villains and their schemes to be absolutely gripping, but they aren't; the players keep wanting to play their characters as well as the characters deserve, but it's not happening. I make my character a former slave but when it comes up in play it's because I force it to, and my fellow players dodge eye contact and the GM wants to get on with the plot.
A game where the meaning happens mostly during play is also easy to spot: everybody gets it and is engaged. Other players than me are into my former-slave character, and when she gets passionate about something, the other players hold their breaths. The GM lets the players pick the villains through their PCs' judgements, then plays them aggressively and directed-ly and hard. Every session is hot. Nobody sacrifices the integrity of his or her character for the sake of staying together as a party or solving the GM's mystery - the action comes right out of the characters' passions.
These characterisations offer a biased picture, but do a good job of conveying what Baker sees as at stake. If I want a game where meaning mostly happens during play, that's likely a game with a decent amount of negotiation because a lot is going to have to be left unsettled until the play itself.
Returning to my point above, one might therefore design for negotiation, but not in order to have the conversation contain negotiation, but in order for meaning to emerge in the conversation rather than being fed into it. Similarly, we should have a
purpose for assertion, in order to want our playful conversation to contain a lot of assertion. To my reading,
@pemerton is thus questioning
that purpose. We can choose to leave it unexamined - we just happen to find it satisfying that way - but for design it's important to ask why it's satisfying? What about it satisfies?