Anyone will tell you that it is the limitations that make creativity work. A novelists who decides to write a western for example will limit themselves certain accepted things. The same for detective stories and romances.
The problem with this aphorism is that it leaves out a word:
good limitations breed creativity. Many limitations are bad. For example, it is a limitation to force a person to paint a picture while blindfolded with both hands tied behind their back. Clearly, since this is a significant limitation, your creativity automatically must be through the roof if you do this, thus the final product will be absolutely amazing! ...or not. Y'know, because most people can't paint worth a damn when they can only hold the brushes with their mouths and they can't even
see the canvas.
Point being, limitations come in both good and bad too. Good limitations cut off dull, boring, obvious pathways, forcing people to show creativity in order to participate. I recently answered a question on ELI5 about "Rayo's number," which holds the current record for the largest construction concept for a number. It came from a "duel" between mathematicians who were tasked to describe bigger numbers than the opponent. It came with two absolutely necessary limitations: every number had to be actually finite, and you couldn't just trivially modify the opponent's previous number. Each new "move" had to be doing something truly, conceptually
new. Without those limitations, all of the moves could have been trivially boring, and the contest would have been a dud. Conversely, if the limitations had required that every number be one that the contestants could actually write in digits, the contest would also be trivial and boring, because compared to the infinite universe of integers, the numbers humans can actually write down personally are (almost literally)
nothing.
All that is being asked by default is that the players operate within an entire world. If the DM has decided there are seven intelligent races that are playable, then that is a limitation but hardly a big limitation. If it were only humans it wouldn't be a decisive limitation. There would still be massive amounts of creativity possible in that setting.
Maybe, maybe not. Note that in many cases this is not the only limitation in question. And, as I have explicitly said already, it can be useful.
This is an awkward example.
What if you can only choose spells from a spell list if you are a wizard. That is a limitation. You can't cast other things. To me that wouldn't be the death knell of a campaign. And I might allow spell creation by the PCs but if I didn't I wouldn't consider it a great limitation.
Is spell creation an official, default rule in the system in question? If it is, I should think a player playing any class officially permitted to use those rules would be rightfully annoyed to suddenly find out that that official, default rule had been taken away. To the best of my knowledge, most systems that have "spell lists" (may don't) this is already the official, default rule. It would be a change away from the rules as written to
receive the ability to acquire existing but off-list spells, e.g. a Wizard learning signature Cleric spells or a Psion learning signature Artificer spells. A player might really want that and might be very disappointed if they couldn't get it, but they would have no room to argue that it "should" be that way by default--the default rules explicitly don't support it.
I agree that if the DM does not provide a setting the players will have to help make it up. I wouldn't play in such a game. I want an interesting world to explore. I want interesting well thought out NPCs to engage with as a PC.
Do you think the only way for there to be a world to explore is if the DM has already nailed down all of it in advance? Because this is
very much not true in many games, both in terms of "game systems" and in terms of "game tables."
Dungeon World has a wonderful concept here: "Draw maps, leave blanks." What this means is, you absolutely should have a map of the Kingdom of Tabletopia and perhaps even for its neighbors like the Duchy of Axygg and the Freehold of Grognardia etc., but you
shouldn't nail down every single village and town, every single river and forest, every single dungeon, etc. You do enough work that people can understand the setting and the concept, so the group has something to sink their teeth into, but not so much that there's nothing for
you, the DM, to discover as play progresses. As part of this, it is valid (under particular circumstances, not just willy-nilly) for the players to sometimes be the agents of discovery, who tell the group that a particular location is somewhere. It isn't that they are "retconning" or "rewriting" the setting. They are filling in the blanks on the map--places that weren't important enough for the party to know about before, but which they have learned about because it now
is important to know what's there, just as you would if you were making your own map of a real place as you travelled through it (though, of course, with the addition of being a creative contributor, not merely an observer.)
I suppose it is theoretically possible a DM could make a world that is too restrictive but it would be an absurd premise.
It really isn't absurd at all. To assume so is to make the argument circular; you are
presuming that the DM can do no wrong on this front, which is simply not true.
Here is one example I considered once. Everyone has to be a dwarf and the campaign starts deep underground and no one knows about the surface. The entire known world is tunnels and underground caverns turned into dwarven cities. Now that is not going to appeal to everyone but it might be fun for some people. Just be upfront about it with potential players and let them play or not play.
Hmm. I could potentially be in for that, at least as a..."medium-run" game. I'm not really that interested in dwarves, but I could see being one of the dwarven visionary types who is dead certain there's something "stoneward" (as opposed to "magmaward", since I don't know if these peoples would view it as "up" vs "down" per se.) Once the surface is reached, though, I'd probably want to either retire the character (as their lifelong goal has been reached and they'd be more interested in cataloguing the surface rather than adventuring in it per se) in order to play a surface-dweller, or move on to a whole new campaign set on that surface where the whole point is the group discovering what's up there together.