Apologies for not responding to all of the points. (I tend to get bored/burnt-out on threads once they get into the dozens of pages.) I do think this thread has succeeded in getting a strong discussion going on the topic, so it's probably about coming to its conclusion.
I do want to address just a few points though.
All that being said, I understand your highlighted point. There is the potential that with this rule, when it comes time to solve a problem with a spell, all eyes might turn to the sorcerer. But I don't see how that is an identity problem for the sorcerer. They are about being magic. They live and breath magic that sings in the deepest parts of them. It is so innate to them that they require minimal effort to tap into that well of power. Nothing about that story tells me they should be locked in place, unable to alter the raw magic of their soul into something else.
Again, I don't disagree with most of your points or practical examples. I do, however, have a different take on what you're addressing in this paragraph.
For me, wizards are the ones best able to procure any spell. Sorcerers need to be inherently limited in that. Do I feel they
need to be limited in the ability to change what spells they know? Not entirely. Do I feel they necessarily
need to be prevented from changing a spell known every day? Not entirely.
But they need to be limited in both of those someway that goes beyond the limitations that would remain with Spell Versatility.
And, the only issue for the wizard, is that if a problem needs a solution later they may not be the only one with that solution. But, does that change a wizard's gameplay decisions? Does the wizard look at their list and say "well, a sorcerer might be able to grab this, so I won't need it?"
I don't think it does. Many of the most common "we need a spell to solve this" scenarios are covered by the divine spell list as well. I would say there are very few uniquely Arcane spells that are designed specifically to overcome a challenge that can be delayed anywhere from 24 hours to a week. And that has not harmed them yet.
It's not that the wizard might not be the only one with that solution--it's that they might not be to have that solution at all (they need to find that spell somewhere). By contrast, the sorcerer with Spell Versatility is guaranteed to be able to have the solution, and to have it tomorrow. That is
huge for that particular issue.
I think there are quite a few non-divine spells that can solve problems that can be delayed until tomorrow.
Spell preparation is not a wizard thing. It's one of a choice of two broad mechanics wizards happen to use.
Wizard spell preparation is more limited than other prepared casters. Do you feel they would be balanced if they had access to every spell on their spell list rather than being limited to a subset of them in their spellbook? If that were the case, I'm not sure I'd have an issue with sorcerers having Spell Versatility, but I'd have to think about it more. It would solve the identity issue, because wizards would still be superior in the Tomorrow Spell Access and Extended Spell Access categories. I
might still have some issues with Spell Versatility for sorcerer class identity, but they wouldn't be related to
relative class identity compared to wizards.
Those spells on the sorcerer list are there because they are meant to be options for the sorcerer to use. There is currently no practical use in having placed those spells on that spell list because the limited spells known prevents sorcerers from using spells meant for sorcerers to use. Sorcerers are meant to be an alternative choice to wizards and in doing so there is some overlap, including the expectation that a sorcerer might teleport the party, open a planar gateway, or scry on enemies.
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See above. The limited spells know makes those spells that sorcerers have and are meant to be used by sorcerers available instead of a superfluous addition to a list that pragmatically cannot be taken.
I'm sympathetic to this argument.
You want to resolve that by adding to the spells known list. I think giving sorcerers more spells known impacts the wizard identity more than a sorcerer doing arcane things during downtime because adding to spells known impacts your point 1 above. Point 1 is the game play standard.
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All eyes should turn to the character filling the same role of the wizard in the arcane caster the party has. All eyes are never going to turn to the sorcerer unless we make forced assumptions that a single spell is required and only the sorcerer list has it and the wizard wouldn't have added it to the spell book already.
But as I mentioned, I'm as much concerned about what it says about the world as how it affects PC party gameplay. Wizards are the people you might visit because they can come up with the solution to any arcane spell access problem if you give them a day or a week. A sorcerer you'd only visit if you think their particular area of emphasis is relevant. With Spell Versatility, you'd go visit the sorcerer unless you knew the spell you needed wasn't on the sorcerer spell list, because the sorcerer is guaranteed to be able to have the spell tomorrow, while the wizard isn't.
In other words I find Point 1--Immediate Spell Access--to be the
least important for class identity of the three. I wouldn't find it a challenge to wizard class identity to limit the number of spells they could prepare per day to the same number as the sorcerer's spells known (assuming no Spell Versatility). I wouldn't favor that sort of wizard nerf, but if there were some sort of gain that went along with it, I might consider it.
Or those players have a different opinion on what is creating the class identity for both classes that simply does not match your own.
Accusing player of not caring simply because they have a different opinion is incorrect and insulting, and does not directly respond to any points made. Your posts are usually much better than that.
I'm sorry if it came off that way. I wasn't trying to be insulting. There are some D&D things that I don't care about myself. I was actually attempting to acknowledge assumptions under which my claims wouldn't be relevant.
The UA changes are addressing one of the important levels of spell access that you did not list. Swapping spells out on leveling up. That was a concern and the expectation was that classes that use the spells known mechanic were to be swapping out spells more frequently than some campaigns were allowing.
5e's entire spells known mechanic has always assumed that these classes would be swapping out spells that were less useful to the campaign as it progressed. This always included access to the entire spell list.
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This isn't about buffing classes. Spell versatility was about addressing a concern regarding the frequency of the current implementation. The current implementation is the ability to swap a single spell regardless of level, and that level exchange is still only something available on leveling up.
Yes, and I disagree that Mr. Crawford's solution to the stated problem is a good option. First--I'm not entirely sure he's correctly identifying the problem. He gave us his conclusions about what the problem is, and a suggestion that would address those conclusions. If he incorrectly identified the problem, then his solution might not fit. Second--He doesn't appear to recognize the significance of Tomorrow Spell Access or Extended Spell Access with regards to differences in sorcerer and wizard identity. That being the case, his solutions are unlikely to be informed by them, and we have vast disagreements about the value of said solutions ;-)
Here's an idea of how to make us of Spell Versatility without challenging those elements I ascribe to wizard spell identity. It's messy, I'm not sure I like it, and I'd have to fine tune it, but as a minimum change to highlight my position, here goes:
At level 1 a sorcerer selects six 1st-level spells on the sorcerer list that he does not know. These spell cease to be sorcerer spells for him, and cannot be learned through any feature of the sorcerer class. When he gains access to spell levels 2 through 5, he likewise selects spells of that level that he does not know on the sorcerer spell list (four for levels 2 through 5, and two for levels 6 through 9) which also cease to be sorcerer spells for him and cannot be learned through any feature of the sorcerer class.