[MENTION=22779]Hussar[/MENTION] has made it clear that the point of summoning the huge centipede was to circumvent the desert trek. That is, he as a player was hoping to reframe the current ingame situation, from one of "How do we cross the desert?" to "Now that we've crossed the desert, how do we achieve our goal?".
I would argue that reframing a game situation is a meta-power, and not something that is usually on a D&D character sheet. His ability to summon a huge centipede is ability to alter the in game environment. It is not the same as having the ability to alter the game, and when you conflate the two then there is going to be problems.
D&D traditionally has many mechanics which have more-or-less this function: flight (at least in some modes), teleportation, ultra-high Perception bonuses (reframe scenes from "How do we find?" to "What do we find?"), ultra-high Diplomacy bonuses in 3E (reframe scene from "How do we deal with this troublesome NPC?" to "What does this NPC do to help us?"), etc.
No, you are confusing function with outcome. Teleportation has the function of transporting you within the in game world in a reasonably reliable instantaneous method. This has the expected outcome of causing a new scene to be framed - the destination you arrived at. But the function of teleportation isn't scene framing, nor does it give the player the right to set the scene. The right to change your in game space, whether it be by walking across a room or teleporting, doesn't give you meta authority. You have narrative control in as much as you have certain reasonable expectations with regards to proposition outcomes and within the world teleporting is probably a reasonable rare and powerful ability. But you still can't set the scene.
There is a serious design question about whether it is good to hide scene-reframing capabilities inside what are generally action-resolution mechanics. For instance, it produces the sort of confusion/conflict we are seeing in this very thread - a player like Hussar tries to reframe the scene to avoid having to engage in action resolution with a scene s/he doesn't like, and the GM responds by treating the reframe as a move within the previously framed scene rather than an attempt to move to a new scene.
That's because it isn't actually a scene-reframing capability. It's merely action-resolution mechanics. There isn't an attempt to hide it; it just isn't there. And beyond that, Hussar's attempt to reframe the scene with a summon centipede involves not merely mistaking action resolution for scene framing, but involves a blatant attempt to circumvent action-resolution itself.
I think you are trying to draw a sharp distinction between scene framing and proposition resolution that from the perspective of the DM doesn't necessarily exist. In a traditional RPG approach, there aren't necessarily big jumps between scenes. Instead, each scenes flows into the next one like frames in a movie, with the assumption of very little time passing between them. For example, the DM responds to, "I summon a huge centipede", would lead to a scene like, "Ok, there are sparks and a smell of brimstone and an undulating 40 foot long hundred legged terror appears.", which might lead to, "I mount the centipede and head north into the desert.", which quickly leads to the next scene of, "Ok, you begin riding the giant centipede across the desert. You find it rather difficult to hold on to its smooth chitinous back. Ahead you see the terrain becoming more rugged, and a steep wadi cuts across your immediate path to the north." In each case the DM is acknowleding the PC's proposition, validating it, describes the outcome and awaits the next proposition. Each new outcome is itself the scene that the PC is expected to respond to.
The DM is continually setting the scene, and the PC is continually directing the action with in it which leads to the next scene according to the logic of the setting. These big jumps between scenes where we stay stationary and do intraplayer RP until that pitters out and then we do a bang and big jump to a new scene aren't really a part of traditional D&D.
But the real issue is - who gets to control scene framing? If the game's answer is "The GM" then there is a huge onus on the GM to frame decent scenes. And if the players are using their resources to try to reframe towards scenes that they find more interesting, I personally don't blame them for that!
If you look at my description of play above, you'll see that the responcibility for scene framing always lies with the DM, but the DM hasn't really asserted full control over the scene. The series of scenes is actually to a large extent being determined by the player, with the DM filling in the details. And yes, there is always a huge onus on the GM to frame entertaining scenes. And yes, players are always trying to direct the action within a scene using thier resources to make the situation more interesting for themselves, however they define that. And I don't blame them for that either. But again, this is such a vague description of the how a player does that that it is meaningless.
And he is under no general obligation to "trust the GM". In the labyrinth example, he's talking about 20 hours of play. GMs earn trust by framing scenes that their players want to engage. And by recognising signals to the contrary - such as the summoning of giant centipeds to avoid having to actually play out the trek across the desert.
Well sure, DMs can show that they aren't fully trustworthy. You are under no obligation to trust a DM that show ineptness or demonstrates that he lacks the emotional framework to DM fairly.
I guess that would be one way of doing it. Another well-known technique is that of "say yes or roll the dice" - that is, crossing the desert or passing through the labyrinth is handled by fairly speedy free narration, and the action is recommenced in a situation that is engaging to the players.
I'm aware of the techniques, and though I'm not completely in agreement with your description of 'say yes or roll the dice', I'll let it slide as off topic. I'm telling you that they aren't applicable here. You can't handwave events of potential substance. I agree you should handwave events without substance. Even if we are playing a nar game, the story teller is perfect in his rights to counter with a bang of his own. You say, "We drive to St. Louis"; I say, "But you run out of gas in Kansas." But nar games are marked by their lack of detail. The world is created as you go. The desert doesn't exist until you decide to enter it. It has no story meaning until you vest it with meaning. But that isn't the situation here. I've previously created the desert. I know the things that are in it. The counter bang is therefore inevitable, because I know there is an event in the desert and probably lots of them. And I don't know how the player would react to them. It is not possible to hold within my head, 'They crossed the desert' and 'No events occurred'. What you are proposing to create is therefore a non-linear story line. At a later point it is entirely possible that the knowledge the character gained crossing the desert would be referenced. There was a crossing of the desert and things happened in it, but we kept them out of the current story with the possibility of coming back to them. That's just a headache. That might be acceptable within the structure of a nar game, but one of the reasons I have little interest in nar games is that they don't ever seem structured to the sort of 200 plus hours stories that I'm used building up within a campaign. Those quick bangs are possible because the story is emphemeral anyway.
Like I said, if this is the movie of the story, you should handwave any passage of time that is event free. But, for example, you wouldn't tell the story of Indiana Jones and the Raiders of the Lost arc handwaving from the arrival in Egypt to the point say where they descend into the snake pit. Lots of important story points occur during that part of the journey. Nor would you handwave the journey from the time when Indiana escapes the snake pit, until he recovers the Arc again. Lots of excitement occur along that part of the journey. When you tell me you want to handwave the crossing of the desert, that's fine, if the crossing of the desert corresponds to part of the story in which nothing exciting happens. But if the crossing of the desert involves a battle up and down dunes and through wadi's between a giant centipede and a monstrous scorpion, while the PC's leap back and forth from the backs of two beasts, or the discovery of the lotus eaters and thier fields of valuable magical flowers, or of the black pyramid where is entombed the body of the dead god, or whatever then that's not a part of the story you reasonably handwave least of all in an RPG where the DM doesn't know what is going to happen in the desert and what choices the players would make.
Obviously this is not a point on which there is universal agreement, as far as RPG preferences and techniques are concerned. For instance, when I am GMing I rely all the time on signals sent by the players as to what is or is not interesting to them.
Well, I do too, but my usual responce is to make sure that the powergamer has loot to find in the desert, the thespian has reasonably RP oppurtunities to find in the desert, the problem solver has riddles to solve and traps to uncover, and so forth. It's not usually resolved by granting scene setting authority to a player who frankly has no clear idea what the setting actually is.
As for things being in the desert - if the players summon a huge centipede, and there is (say) a hidden temple in the desert that I think would be interesting for them to encounter, it's pretty easy to narrate "After X days of hard riding on your summoned centipede, you see some worked stone sticking out of the desert sands in front of you."
Well, sure, and if the desert is really only a shrodinger's map, and this is a railroad where the players always do what I want them to do, and if there is nothing else but the abandoned temple in the desert, and there is nothing set by the prior scene that makes the remainder of the day important, then a handwave like that is what I'm likely to do. But that is a lot of big ifs and it's is not at all clear to me that I'm really offering the players more freedom and control running the game that way.