Celebrim
Legend
I think this can be accurate, but within limits.
The limitations of the English language and my necessary position within the debate make it difficult to introduce the full level of nuance I have on the topic into the debate. There is I think some give back and forth between culture and law. A particular culture is more likely to flourish under a set of particular laws, or may be more accurately, a set of laws tend to push toward certain cultures and away from others. But its not as hard of a shove as we usually think it is, and so to make that point stick as well as I can, I'm tending to ignore the in my opinion quite small effect law has on culture. So yes, there is a limit, and when you get closer to where I think it is then I'll be happy to admit it.
For example, a few years ago we played a 3.5 Eberron campaign where the PCs were all goblins. And it was a VERY different experience playing a character from that perspective--undersized, ugly, socially misunderstood, fighting for respect tooth and nail. Not that you can't play a character like that being an ugly gnome, or whatever, but the shared perspective of ALL OF US being goblins made for a much different type of experience.
One of the first complaints you hear when you break out of the culture will be some variation of 'that's against the rules'. I can just imagine someone going, "Well of course you have a different experience, because you added a new mechanical restriction to the game - 'Everyone has to play a goblin.' - and thats why the game was different." But I think you'd agree with me that it wasn't the mechanical difference of being a goblin (compared to some other race) that created most of what was different about the game.
If Savage Worlds feels different from D&D, or GURPS feels different from Cthulhu, it's partially player expectation and culture, but it's also because the mechanics interpret player's physical interactions (and their results) differently.
But the thing you have to consider is that there is a culture to game creation that determines alot of that as well. If I ran my house rules for D&D and I also bumped up the CR of all opponents by 4 or so, with no mechanical changes I could run a pretty straight up Call of Cthullu game with all the attendent changes to how players approached or felt they had to approach the game. All the sudden those 'Deep Ones' encountered at level 1 would go from fearsome foes greatly to be respected, to virtually unstoppable killing machines greatly to be avoided and quite capable of inspiring fear and horror. Now granted, this is facillitated partly by the fact that the Ravenloft Fear/Horror/Madness rules are incorporated in a standard way to my house rules, but the culture of the game created by simply changing the expected difficulty of a fight with a monster is huge.
And likewise GURPS can run Call of Cthullu pretty well as well just by changing the games culture and tropes to 'Call of Cthullu'. I don't know 'Savage Worlds', but I'd be willing to bet...
One of the things I like about new players is that they don't bring these preconceptions to the table, so that if I run D&D as a strict horror game no one feels like I'm doing badwrongfun because the game they have isn't the game they believe D&D is. Experienced players of course have played D&D (and probably one or more other systems) as a horror game, a high fantasy game, a low fantasy game, a gritty realism game, a superhero game, a melodramatic nar game, and a bit of everything else under the sun and so they are mainly just curious to find out what sort of game they are in before they relax and get into it.
Does that interpretive mechanism work the same way for every player, identically? Of course not, because everyone brings something different to the table, but I'm not totally comfortable assigning all experience to just a shared "group think." Rules systems are built to create a different experience.
This is certainly true, but you can't draw the inference that if a rules system is failing to provide a particular experience that the failure can be ammended by changing the rules. Nor can you be assured that if you are having a particular experience with a game that it is a result of the rules.
And to really make matters complex, I'm the sort of person who tends to treat portions of the text that I feel are related to creating a particular culture as mere guidelines for novices to be discarded or replaced as needed to create the particular game I want, and I don't feel like I'm changing 'the rules' (as for example in deciding that average EL should be EL+4, or your groups decision to all be goblins), where as some people reading the text will tend to treat that sort of thing as having every bit of importance as the mechanical resolution and will treat me (or whoever) as someone who is 'breaking the rules'.