I guess I am not at all sure what it is exactly that 'rule 0' is good for. I mean, at any given table the participants in the game can decide to defer to the GM (or even someone else) as they see fit. Furthermore, the GM, regardless of what is written, can only exercise authority over the table which the other participants are willing to give them. Thus, IME, the concept of rule 0 is really kind of empty. It is more simply a fairly aggressive statement of an expected idea of how the designer imagines things working. Likewise the non-existence of a rule 0 in no way precludes the participants from deferring to the GM (or whomever) as they wish. Again, its non-existence is, perhaps, evidence of a certain orientation in the designer's mind (but maybe not, negative evidence being hard to interpret and all).
The upshot being I'm pretty much drastically skeptical of any statement that there even ARE any meaningful categorizations of games into 'rule 0' and 'non-rule 0' categories to start with (while admitting you can certainly sort them textually this way). I might be more amenable to the notion that there are 2 categories of games, ones where it would be POSSIBLE to state a rule 0 without fundamentally undermining the concept of how the game works, and those where it is not possible.
But maybe even more to the point, I reject the notion that there is some 'range of experience' which rule 0 somehow enables! Now, your scenario above might in fact 'break the rules of' games like Dungeon World, etc. However, I don't think that's really a problem. I mean, setting aside whether this would be a good thing to have happen in such a game, if the GM is a fan of the characters, etc. then what's the problem? Why does rule 0 somehow make this work, but it won't in DW? I would do something more interesting in DW, but handing over my character to the GM so they can tell a story about him for 5 minutes, not a biggy!
This is a bit mind boggling to me. The basis for all my statements regarding rule zero is based on the background that I have read a lot of criticisms of it as a sign of bad design, and that that was a very heavy deal in the advertisement of the early forge games. The argument was that the designer claiming full responsibility for the entire ruleset and conduction of the game made for a stronger design than ones clearly deferring rules control to one of the participants.
As such your questioning if rule zero is meaningful or not seem to be in direct contradiction to the cultural context in which my statements are made. It feels a bit like me making an argument christmas trees has benefits, and you reply with - is there even meaningful to talk about such a thing as Christmas?
But I can spend a bit of time indulging this higher meta questioning. It is completely true that any group performing an game can by consensus override any rules of that game. Hence if you allow for that indeed no game can be more flexible than another. It is theoretically possible to invite people over to a game of trivial pursuit, and end up playing something identical to D&D while your group still call the activity Trivial Pursuit (with some house rules).
For any discussions of the level of flexibility of games to be meaningfull one hence have to be more clear as to what level of strictness one assumes the group to be bound by the game. The standard minimum criteria for discussing properties of games is that the group indeed follow all the rules of the game, and consider it a new game if any changes to the rules are made. For most games this sets unproblematic boundaries that allow meaningful communication. However for games with a ruleset that explicitely (or implicitely) calls for one of the participants to introduce or override rules, this become a bit more problematic. What are the boundaries for communicating about that game? Some possibilities:
1: All changes to the game is acceptable and under examination. When discussing D&D, we should consider the possibility of the DM turning it into a trivial pursuit clone trough their authority.
2: All changes not actually overriding something stated as if a rule in a resource not nominally meant for only one participant is accepted, and under examination.
3: Only additions of rules covering situations where there are no suggestions in any of the core material is accepted. If there are a presented set of suggested options for handling a situation, one of those must be chosen.
4. We are disregarding the statement about GM rules control, as something fully external to the game we examine. We assume game will restrict itself to situations where there are clearly defined rules.
My impression is that most of those posting in this thread has been sonewhere close to 2 or 3. My arguments for D&D being flexible has been from a 2 standpoint, but I can recognize that this might not have been as obvious as I would have liked as I only tried to clarify that in some of my, now drowned out posts. If I were to use an understanding closer to 3 as basis, I would fully agree that D&D do not appear very flexible indeed.
I think also I have seen some arguments that appear to be close to basis 4 as well. This is the kind of basis where questions regarding if D&D is indeed a game at all, due to it's incompleteness very easily can manifest. However for the purposes of this thread, using this basis seem a bit weird, as in this case the premise of the thread - D&D dm having large control is not as obviously valid as with understanding 2 and 3.
As such I would have expected any potential argument for rule 0 not being relevant/meaningbearing to come from a 4 perspective. That you appear to raise the argument from a more extreme standpoint than 1 (arguing all changes to any game is under examination) is a bit baffeling. I am not saying it is invalid or wrong. I am just a bit concerned with how such a basis for comunication would be likely to provide any meaningful insight into the virtues of different degrees of GM control?
