RPG publishers publish game structures to provide game content so it can be used by referees to present to players.
This is not a very accurate description of most of the TSR-published material that I have. It is game content, but it is not game structures. For instance, I have material that talk about stone walls and floors, about peasants, about plants and flowers, about food and drink, about kings and rivers and borders and countries. Countless pages of such stuff, mostly published by TSR between the early 80s and the late 90s. This is game content, but the expectation is that the players will know how to interact with it based on their knowledge of the real world, and imaginatively projecting. There are often few or no game rules associated with this stuff, and certainly not enough to regulate even half of what players might try and do with it.
Just to give one instance - suppose a player says, during a bar-room situation "I spill my beer on such-and-such an NPC so we'll be able to identify him later by the smell of beer on his clothes". Nothing published by TSR that I'm aware of has any rules for resolving this game move. It depends entirely on imaginative projection of the properties of cups, of beer and of human noses as the participants know them to be in the real world.
"Shared fiction" is frankly is Forgite dogma that is irrelevant to all role playing games. It is part of the uniform design which identifies storygames. There has never been shared fiction in D&D. There are only the related game constructs behind the screen.
This is just nonsense.
Seeing as you love talking about role playing in the social sciences, I'll give you an example. I teach in a law school. I therefore have to write moot problems and exam questions. Many of these involve fictions. For instance, here is one from last semester's exam:
SEN Bakery Pty Ltd (‘SEN’) is a world-renowned producer of high-end cakes and pastries sold on the wholesale market. In 2010 SEN entered into a five-year contract with Perfect Patisseries Pty Ltd (‘Perfect’), a retailer of cakes and pastries, under which it agreed that it would not provide goods or services to any other commercial enterprise. However, SEN is now threatening to break its contract and to start supplying its wares to a rival patisserie.
Can Perfect receive an order of specific performance requiring SEN to perform the contract, and/or an injunction to prevent them supplying the rival patisserie?
Answering this question requires the students to entertain a fiction - to imagine the existence of these various made-up companies and their made-up contract - and then to reason from that imagined situation. Some of that reasoning is pretty mechanical. But not all of it - for instance, the students have to decide whether the company SEN is more like the singer in
Lumley v Wagner, with other options available which make an injunction permissible, or more like the steel company in
Atlas Steels with no other options open which hence would make the injunction impermissible. That decision requires thinking about the fictional properties of the fictional company and comparing them to the real properties of various real-world litigants in the decided cases.
Answering that question does not require any story-telling skill. It only requires lawyering skills. It nevertheless involves working with a fiction. It is quite different, in that respect, from playing Chess or Go which doesn't require entertaining an imaginary state of affairs.
Here is another example. We run client interview competitions. These require students to pretend to be lawyers interviewing clients. This is a roleplay in the literal sense, and it involves fictions. Imaginary fact situations, like mine above, have to be created. Client personalities and motivations have to be authored. Etc. Fiction, and imagination, is inherent to roleplay. It's how you do it.
And I can tell you, law students have been answering questions about made-up fact situations, and engaging in client interview exercise, long before Edwards ever set finger to keyboard.
there is no such thing as a shared fiction ever. Stories
Your insistence on equating "fictions" with "stories" is a huge impediment to talking about this issue with you. I have just given an example of a fiction that is not a story. Thought experiments in special relativity are another example.
And there most definitely are shared fictions. I shared the above fiction with over 100 students sitting last semester's exam.
In D&D the referee mediates their moves upon the hidden game board. They take measurements, roll dice, attempt to relay clearly and accurately what the positions player's pieces and have the game defined abilities to sense.
<snip>.
Players map in their imagination the reality the DM is relating.
Can you not see how tortured this is? You talk about moving the players' pieces, and then talk about the game-defined ability of those pieces to sense. Sense what? The "pieces" are inanimate objects. They can't sense anything. And all that the players can sense is the GM's screen and the table in front of them. All the "sensing" is imaginary - it is the imagined sensing of imagined things by imagined characters. The content of all that imagining is a fiction.
Likewise your reference to "the reality the DM is relating". When the DM says "You see an orc" what reality is the DM relating? There is no orc. A fortiori, then, no one sees an orc. It's all made up.
Here is another example that proves my point, from Gygax's DMG p 71, discussing the resolution of a player's action declaration of hurling oil at a monster:
Where is the oil? In a pouch, of course, so that will take at least 1, possibly 2 segments to locate and hurl.
What is Gygax talking about here, given that the oil, the pouch, and the indicated moments of time, all DO NOT EXIST? He is talking about imaginary oil, in an imaginary pouch, in which imagined time is passing. And the GM is resolving the action by reference to that imagined fiction. This is what is sometimes called "free form roleplaying" without the need to use mechanics.
And this is not a special case. It's inherent to RPGing. It's the difference between RPGing and chess. Chess does not require imagining a pretend situation. It does not require asserting any propositions that are false when evaluated against the real world. Whereas RPGing does. It requires asserting propositions about the existence and location of oil, and the passage of time, all of which would be false if evaluated against the real world. (But the participants know how they are to be evaluated, namely, relative to the shared fiction.)
This also has nothing to do with storygaming, or The Forge. Gygax is not discussing storytelling. He's discussing playing a game. But part of being good at that game is having the ability to think of clever things relative to a fiction. It's not just pattern recognition, anymore than playing Pictionary, or "I spy with my little eye", is just pattern recognition. (Nor is playing basketball just pattern recognition, for that matter, though for reasons different from RPGing - in the case of basketball it's because the game has a huge physical/athletic component.)
Your repeated assertions that all gameplay is pattern recognition is more dogmatic than anything that ever came out of The Forge.