I disagree that there's no secret backstory. When that map hits the table, it resolves a number of things immediately that, prior to that, only the DM knew.
Prior to that,
no one knew them to be true of the shared fiction, because the fiction wasn't established.
For you, secret notes are good for encounter prep - and the secret is revealed when that encounter happens due to player declarations
This claim is just wrong. The next passage or two will elaborate.
If the player declares they open the door to see what's behind it, and you drop down that encounter map, that's secret backstory the DM is telling to the players because they prompted him to reveal it (to phrase it like you do).
It's not secret backstory used to adjudicate an action - exactly as you say, the players are looking for the GM to narrate some more fiction.
But if the player opens the door to find the secret exit, and the GM (with no reference to action resolution mechanics) drops down a map with no exit, then that
is secret backstory used to adjudicate an action.
They're different cases.
A third case, also different, is if the player fails the check - and so opens the door hoping to find (say) a study but instead finds a kitchen. Or a study infested by bookworms (so to check it out involves risking the papers I'm already carrying). Etc.
I'm absolutely certain that you're okay with an invisible enemy being in a fight as part of DM notes on the encounter, but you're not okay with a DM's notes discussing the existence of a map. I haven't yet seen you address this difference to any degree.
I set out three criteria: (i) knowability; (ii) salience; (iii) consequence/impact. The absence of the map from the study and its presence in the breadbin, in my view, tends to fail all three.
And if you misunderstood the player and the really did want there to be an invisible opponent (it's happened before in my games)?
Then the GM apologises and sets a DC.
Clarifying intention is an important part of establishing what is at issue in action declaration.
This is how the above cases I've distinguished are identified - eg if the player says "I look behind the door", you need to clarify what their intention is (what do they hope to find? are they just fishing for more narration?) You can ask. (Sometimes I do this.) Often, the play of the game has a momentum, and the situation is charged in such a way that the intention is evident. (And if the GM cocks it up and has to roll back a little bit, well, that can happen to - you do your best to recover the pacing that was lost.)
I also don't understand why you say I didn't answer your question about an invisible opponent from the 4e perspective: I posted an actual play report that deals with two such instances. So those show not just how I would, but how I did handle an action declaration that pertained to an as-yet unobserved (ie invisible) person/creature in the situation whose presence in the situation was not established by prior notes. And you even responded to what I posted, so I'm not sure what your complaint is?
In the second example, how is the duergar not secret DM knowledge in that situation?
Because it wasn't an established element in the shared fiction until introduced in response to the player's successful check.
This also illustrates the difference between prep (I came up with the idea to use duergar if extra NPC elements were needed) and authorship (that idea didn't actually generate any shared fiction until the player made a check that - because it succeeded - required me to introduce some element into the situation beneficial to his PC).
Your first example is... well, to be blunt, it rings all kinds of alarm bells for me.
Well, I wouldn't do it in a game with strangers, if that's what you mean. Among friends, it was a lot of fun and the player's response was well worth the price of admission!
It's also not strictly a detriment to the player. In 4e - played by the book as that campaign was - the extra creature generates extra XP, so the time and effort spent working out how to deal with it contributes to the progression of the game. The player hasn't lost anything in noticing the roper. (It would be different in some other systems. In those other systems I would therefore make a different GMing choice.)
And notice that it does not involve any secret backstory.
4e encounter math wasn't very forgiving
<snip>
This is one of the reasons games like D&D usually need encounter prep.
It's a tangent, but I've got no idea why you think this. I've GMed quite a bit of 4e across all three tiers. At paragon and epic (and really even upper heroic) the maths is extremely forgiving, in the sense that stepping up an encounter from (say) level +2 to level +3 will up the pressure a bit, but is in no way likely to entail a TPK.
In my experience you can chuck all sorts of stuff into a 4e encounter at those levels and the players just dig deeper into their pools of resources.
If the player asks for a map in the study and succeeds, that's a suggestion to the GM as to possible narrations -- either the DM says yes, that's exactly how it happens, or he narrates the success in a way that advances the scene.
<snip>
So, in all cases, as I understand it, all player action declarations are, at best, suggestions to the GM as to possible narrations of future states of the fiction.
Two things - in some systems it's not a suggestion to the GM as to the content of the fiction: rather, it's part of an action resolution process which, if it succceeds, bring it about that the desired state of affairs is part of the fiction.
The GM can circumvent the action resolution process by "saying 'yes'" - so either the GM accepts the player's view as to what the fiction should be, or the dice are rolled and they tell us if the player's view is to be accepted. The player is not making a mere suggestion which it is up to the GM to accept or not.
Second thing: in BW it is the player's narration that determines the character of success. The GM is permitted, at best, to embellish - and the player is entitled to veto those embellishments if the player regards them as contradicitng the successful intent.
If the player declares that their opening the door to the study (they're announcing they think it's a study, this isn't established yet) and that the door will open on the long axis of the room, but your map has the doors on the short axis... The reason this doesn't catch is because you have a blind spot
Again, what's the case? Are the players conjecturing but don't really care? Then it's simply easier to stick to one's prepared map.
Does the player declare the action because something is at stake (demons can only appear in rooms with the door opening onto the long axis, let's say) then I don't have a blind spot - its exactly the sort of thing I've been talking about (of secret backstory being used to adjudicate action resolution).
Part of running a game in what Eero Tuovinen (per blog lilnked to upthread) calls the "Standard Narrativistic Model" is having a good sense of what is at stake and what isn't. That's a big part of what will make the game work, or fizzle. In my own games, opening doors to see what's behind them is very rarely a part of play. Opening doors as part pf am action declaration to find something behind them is also quite rare.
Those details of geogranpy and architecture don't figure much as more than colour.
you've previously denied that you engaged in prep in your Marvel game, despite prepping quite a bit. Maybe that prep was fast, but it doesn't change the impact on the game -- essentially you built an encounter map of Washington, DC, and then just moved around that map.
There was no map, either actual or implicit. There was a hotel room - mentioned, but no action took place in it.
There was a bar - scene distinctions Dark Bar and Seedy Back Rooms. As it happens, these didn't come into play - the action fairly quickly moved out of the bar. War Machine left Diamondback Stuck on top of the Washington Monument - that didn't need a map. Everyone at the table knew that the Washington Monument is a tall, pointy thing. The player just declared his action ("I interrupt my romantic flight with Diamondback to check out the intruders at the Smithsonian - I'll hang her on the Washington Monument!") and we resolved it. When Bobby Drake's player wanted to freeze the pool at the base of the monument so he could go ice skating, no reference to backstory was necessary - everyone at the table knew that there is a pool there.
Likewise the use of other locations (the Capitol; the Smithsonian) in the game. At one stage, just to check that what I was narrating made sense, I checked with one of the players who has been to DC (I never have, nor looked at a map of it that I can recall).
Establishing the fictional situation by incorporating a real place that everyone knows, and which therefore gets incorproated into the GM's description of events ("You get a radio message - there are intruders in the Smithsonian") and into the players' action declarations ("I teleport to the top of the Capitol") essentially as colour, isn't anything like the GM unilaterally pre-authoring backstory and then secretly (as in, without revealing it) using it as part of the fictional positioning for adjudicating the success of declared actions.
you're okay with action declarations that involve the DM telling more story, so long as the DM didn't write any of that story down beforehand? What if the question is an augury about the study, and your encounter map and notes indicate a dangerous encounter awaits there -- how do you not refer to your notes then?
I generally won't have an encounter map and notes of that sort - ie a series of mapped out, linked locations with a key - so generally it can't come up quite in the way you describe.
But if a player uses an augury to try and get me, as GM, to tell them more stuff than in 4e I'll tell them more stuff. In BW I'll often tell them to better form their action declaration - what exactly are they hoping for? As I said, this sort of "GM narration triggering" is close to degenerate for BW. Not completely - if the scene really is incomplete in its framing, the player can trigger more - but to the extent that it's an attempt to squib, or to push the
GM into making the choice instead of the player (eg "Now I know there's something dangerous there, it's easy to turn down so-and-so's request to go there") then the GM is entitled to turn the pressure back onto the player (eg if the player wants an excuse to make it easy for his/her PC to turn down the request, then s/he has to own it).
I think there's a hugely important difference: the orc is established in the scene, the map's presence in the scene is being introduced by the player. The orc is manipulated, the map is created.
In my view this statement is false, and only gets a semblance of plausibility because the ficitonal is given (metaphorical) reality.
The orc doesn't exist. There are some words about the orc. Then some more words are authored -
the orc is dead, say.
The map doesn't exist; nor does the study. There are some words about the study. Then some more words are authored -
the study has a map in it. In the real world, we treat
the death of a thing as metaphysically different from
the presence of an object in a place for reasons to do with differences in causal processes, constitutive independence, etc (the death supervenes on the thing; the object's existence doesn't supervene on the place, so it might have been elsewhere).
But none of these reasons pertain to the authoring of fiction. Adding a sentence to the orc's description: it's dead; and adding a sentence to the study's description; it contains a map; are identical causal processes. And in RPGing terms, that means they are structurally equivalent game moves.