But, for me, the point of the conversation is to determine what differentiates simulation from just playing the game. Every RPG has situation resolution mechanics. Every RPG has some sort of mechanic for determining success or failure of an action taken within the game. Whether it's FKR's judge, or a Jenga tower, a magic 8-ball, D-Wayne, or a thousand other ways, they all essentially do the same thing - the player declares they are trying to do something and the mechanics tell us whether or not they succeed.
Fair enough. No problem. But, if sim is just illusionism (defined by the pretense that the DM is doing anything other than just making stuff up) then isn't simulation meaningless? If all I have to do to maintain simulationism in a game is have players who buy my line of justifications, that means that every single game out there is a simulation. After all, presumably
@pemerton's players aren't disbelieving him when he declares that the runes are what the player suggested they were. His players are content, so, it's a simulation? Why is anyone contradicting him?
For the record, I have both played and run GURPS 3e and 4e.
OK, problem number one here is that you are misunderstanding what I mean by illusionism. In reality, if the game tells you you failed to climb the cliff because of XYZ, then that's basically the same as if the
GM tells you you failed to climb the cliff because of XYZ--the only actual difference is that one reason was made up by the GM and the other was made up by the writer. The illusion here is the belief that having it in the book is somehow a better sim than coming up with the reason yourself. They're both similating and/or narrating the results, but the authorship is different.
Now, the reason made up by the writers may be more in tune with the game's theme, goals, general mechanics, whatever, than what you come up with, but that doesn't necessarily mean it does a better job at providing a good game. As I've pointed out, there's Gygax's "diseases you pick up because you're basically living in the germ-filled wilderness" tables in the 1e DMG. In tune with Gygax's vision of how to play AD&D? Yes. Does it simulate the reality of living in the germ-filled wilderness?" Also yes. Does it make for a better, more fun game? I for one would say
no, since even if I were to run the grittiest, most down-to-earth game possible using AD&D1e, I still wouldn't find it interesting or fun to have a PC die of dysentery. We're playing AD&D, not Oregon Trail. (It's also not particularly realistic once you consider the fantasy elements and nonhuman biology.)
If the idea of simulation is to give the reason for why something does what it does, then yes, we--players and GM alike--want some level of verisimilitude. We don't want lolrandom. But we don't need or want a game to give us every single answer either, because that would, quite frankly, take up way too much room in the book and require too much detail and time to sort out--and it would be highly limiting. So we want a middle ground. We want a game that does the job well enough to give us the info we need to narrate this particular instance.
Do I
need to know
exactly why you failed to climb a cliff? Probably not. I can look at the situation and make something up. I can ask the player why they think their climb failed--assuming they didn't immediately volunteer a reason (as is common at my table--a player rolls badly and will often narrate the reason for it).
I've talked about doing the math to figure out why a particular roll failed, but that's honestly not that important. If you have disad because of the darkness and the rain, and you failed, but the fail was because your low roll was a 12 +2 for stat +0 for skill and that didn't beat DC of 15, meaning failed because your skill wasn't high enough, the game isn't magically more interesting or realistic if you say
that versus saying that you failed because of the darkness and the rain. Nor would it be more interesting or realistic if there was a "d6 reasons your cliff climb failed" table, or if the skill said "fail by 5 or less: choose one the following: breaking rope, high winds, dangerous cliff face; fail by 5-10: choose one of the following: bad planning, weak arms, mischievous cliff pixies."
These are all perfectly decent ways to play an RPG, but the latter two aren't "better" because the reason for the fall is given within the text. And a sim game
can't take everything into consideration, because that would limit you to what the writer thought about, and
that would inherently limit what the GM can do. If the GM
wants there to be mischievous cliff pixies, but there's nothing in the text that can be interpreted to include such a thing, they're either out of luck
or they have to make something up--which means that the sim game isn't simulating.
--
To me, pemerton's runes aren't a sim problem as a problem with the concept behind it. He said he put down those runes to be "fun and interesting" but otherwise gave them no meaning. Thus, the players effectively have a blank check to do
anything with those runes
. I've said before that the players shouldn't be playing on god mode, but by "hoping" that those runes pointed the way to the exit, and "finding out" that they actually
do mean that, they've shaped the entire dungeon
and its history
and the way its creators thought and built
and the lives of everything that lives in that part of the dungeon, all of which will be different now that there's always been an exit there--meaning the players
were playing on god mode. In other words, the problems with pemerton's runes is that they're
seriously OP.
And as he has thus far refused to say whether or not people can do the same with a sign written in a language in which they are literate, we can't figure out exactly how far this goes. Does the system
encourage this sort of thing? Did pemerton misread the rules, or take them too far? Does the game consider how this ability changes the world? Was this just pemerton? Does
he take these things into consideration when running his games? Or does he simply put no thought into them, in the same way that Gygax never considered that his dwarfs and elves could have different immune systems or different internal organs?
Same with the Lock and the Cook. The players don't have a problem with it, so, it's simulation? But, if the players have a problem, then it stops being simulation?

That can't be right.
If simulation is to have any actual meaning, it has to be differentiated from just playing the game. If there's no difference based on system, no difference based on mechanics, but, the only difference is, "Well, it's simulationist because I say it is" then the term is pointless. It's just tribalism. "I like this game. I don't like that narrative stuff, so, what i like must be simulationist." is not a productive definition.
But a productive definition is not a
useful definition, because games can't be neatly, or even messily, pigeonholed like that. All games have simulationist and narrativist elements. All games have gamest elements to them. I just got the new Discworld: Adventures in Ankh-Morpork game. There are literally
no numbers in your stats. There are only traits. The size of the die you roll depends entirely on how well you can convince the GM that your traits will let you do what you want to do (literally; the game uses the words "plead," "coerce," and "bribe") and you roll against a random number the GM rolls on a d8. This is
the most narrative non-indie game* I know of, with no numerical mechanics beyond a maximum of four Luck Points you can spend on certain things, and you can
still game the system by creating "perfect" traits, if you really wanted to (and didn't understand Discworld).
--
*I've seen Indie games where the "rules" are basically "you're
X; here's the situation," and that's it. And some of them don't even tell you what the situation is. I'm not sure these should actually be classified as games so much as prompts for improv acting, but they were categorized as RPGs on Itch when I got them, so...