I agree, more or less. I don't like the remedy of the DM veto, the declaration "You can't do that." I prefer the remedy of another player asking "Wait, do our characters know - at this point - that thunder damage will be extra effective?" If the barbarian's player responds "No, my character doesn't know, he's making a lucky guess", then I still want the DM to decide what happens *in the fiction* on the basis of whether anyone in town has such scrolls and is willing to sell them (and at what price).
Sure. But, on the other hand, I don't expect the DM to decide that no scrolls are available purely on the grounds that a PC wants one. Fortunately, for me this sort of thing isn't usually a problem, as I have no magic shops to speak of and certainly not ones were arbitrary desirable items are available.
If this is metagaming, then it's the kind of metagaming which I consider useful, appropriate and part of a good story. It is functionally equivalent to playing a PC who is cautious and resourceful... which is one of the many possible forms of heroism.
Agreed. But I've heard of DMs that get upset at this kind of thing because they don't feel that the PC is intelligent or wise enough to be cautious and resourceful, and as such try to put a gate on those decisions because they claim that they don't think the decision is in character for the PC. Such is the perils of deciding that you have a veto on the player's play of their character - they might as well get up from the table and let you play both sides of the screen.
Another example of Riley-approved metagaming: the PCs meet someone in a tavern who wants to join their party, and the PCs find plausible reasons to welcome that person to their party, even though the PCs don't know that this stranger is the PC of a new player joining the group. If the PCs go through the motions of reasonably wary precautions (membership in a faction such as Order of the Gauntlet, or perhaps asking the newcomer to consent to Detect Thoughts or Zone of Truth), then they're establishing a higher level of IC plausibility, but they're still moving towards the answer of yes. (Depending on the table's convention about PCs with ulterior motives, that is.)
Yes, this is the iconic example of positive metagaming. Basically, any time playing your character in a straightforward method might derail everyone's fun, the mature player invents a plausible scene that stays mostly true to the character while maintaining everyone's fun. This burden falls equally on all the players, so if the Paladin's player is trying to reach a compromise, then the Thief's player should be as well.
As for the second, the IC welcoming of a new PC to the party, on the first session of a new player to the table, isn't the GM's fault, because no error has happened and thus no one is at fault.
While I agree to some extent, the GM has a responsibility prior to play for making sure that the players have a plausible motivation to work together, and for establishing a suitably compelling hook in the first session. A GM that leaves all the burden on the player's for coming up with why this group will get together and stay together, and leaves it up to the players to hook themselves isn't doing his job as well as he could. Still, many groups just deal with the weakness of the hook by handwaving right past the problem, but for the more thespian minded this can be unsatisfying. Also, I tend to judge a new group by how well they can handle this sort of RP - the group I have the most fond memories of playing with handled the problem of integrating characters with extraordinary gracefulness.
Tangent: could you perhaps recommend to me an article or essay which explains the Author stance and Actor stance, as you are using those terms?
I could point you to one, but I couldn't recommend it. Besides, the concepts are pretty easy. Briefly, as I use them:
Pawn Stance: The player chooses his propositions entirely according to his goals with no consideration of the character's goals.
Author Stance: The player chooses his propositions according to his own goals, but tries to invent a plausible color for why the character's goals concur with his goals.
Actor Stance: The player chooses his propositions according to what he perceives to be the character's goals based on his understanding of the character's knowledge and personality, even when or especially when those goals might conflict with or sacrifice some of the player's goals.
As I see things, "Pawn Stance" represents immature but not wrong play. It's a starting point and for some tables a sufficient stance for fun, and in cases where there is no meaningful difference between player and character goals - surviving a combat for example - there is really no difference between Pawn and Actor stances. Actor stance represents an obvious and intuitive mature form of play, but is not in and of itself a better form of play than Pawn Stance. The trick and what really separates highly skilled RPers from run of the mill ones, is there ability to recognize when Actor Stance if followed blindly will reduce the fun of the group collectively, and to therefore temporarily switch in a collaborative way to Author Stance to promote everyone's collective fun while still staying in character. Thus, the player that says, "But I'm just playing my character" regardless of how dysfunctional what he is proposing is, is really no more mature of a player than the player in Pawn Stance and arguably is probably less fun to play with. Nor is Author Stance inherently superior either, as in my experience a player that stays in Author Stance all the time is just annoying. What is clever and mature for negotiating a tricky table issue becomes saccharine and groan-worthy if employed in continuous or heavy handed manner. You'd be better off just using Pawn Stance and not dragging things out and slowing the pace of play down.
There is also "Director Stance" where the player attempts to achieve goals by playing the metagame rather than the game, such as by altering the fiction rather than making a proposition within the fiction. In most traditional RPGs, "Director Stance" is limited to the GM, but as you may have noted from the thread some participants are advocating for "Director Stance" as a valid stance for the player as well. In some Indy RPG's, the players have limited resources that they can use to gain temporary rights to "Director Stance" in order to further their interests as a player. Indy designers have frequently made the claim implicitly or explicitly that games which allow shared access to the director's chair are inherently more mature and sophisticated than those that don't, so the participants in the thread advocating for "Director Stance" in 5e D&D are basically trying to show how in doing so they are playing a more sophisticated game than those of us that don't. For my part, I've held the position that "Director Stance" isn't inherently more mature than the other stances and that a perquisite for allowing it into a game is in fact having mechanisms for fairly sharing it and limiting access to it. Beyond that, in my own experience with "Director Stance" in the hands of the players, I tend to find as a player that it doesn't live up to the claims made on the packaging. Specifically, my goals as a player tend to be that I want to have the experience of being a character in a great story, and "Director Stance" inherently interferes with that experience in a variety of ways. Games that advocate for "Director Stance" as a tool for the players tend to mistake the production of a transcript for the experience of participating in a story, and at least for me, I find production of a transcript not the same as participating in a story. Instead, I find that a game that focuses on the production of transcript as the primary artifact of play tend to create the experience of collaborative screenplay writing for the players, and not the experience of being in a story. There is an inherent loss of emersion that goes with "Director Stance" because you are being taken out of character, and certain aesthetics of play like Challenge are harmed by the ability to employ deus ex machina on your own behalf. Heck, I'm not even that big of a fan of "Director Stance" in a GM. Every GM needs a little bit of illusionism and stage craft, but if it becomes obvious you are employing it, then it harms the enjoyment of the players.
