Beyond convention/tradition, if Wizards had the same durability (HP) and could wear effective armaments while casting spells, it would lead to serious questions about the "adequacy" of non-spellcasting classes. To compensate, magic would need to seriously be dialed down. This has generally been what has transpired for cRPG spellcasting for more than a decade. Spellcasters are less fragile (more HP) and can cast more frequently. In turn, there is little to distinguish their spells from any other class ability beyond the animation.
It's an elusive dilemma. Personally, I prefer the older methods. A spellcaster lives and dies by their spells. The spells are potent and costly, but the caster is next to nothing without them.
I very much agree with most of that. Or, I should say, I agree with all of it, to a degree. I think the "older methods" are mildly close to the opposite extreme (with stuff like "you just literally can't wear heavy armor or wield a sword at all," for example). And I don't believe the frequency of casting is as big of an issue. More limited than a Fighter's sword swings, sure. It seems excessive to me, however, to say "you can blow up like 8 things at once with a fireball -- things it would take a Fighter about 30 hits and that much time to take down -- but you can only cast that like twice per day." Or, to put it simply, a Wizard/caster should be able to perform less-potent actions more frequently, and more-potent actions less frequently. That kind of thing.
It definitely sucks when a game just makes them nondistinct, and your caster just becomes a fighter who technically uses magic. But, it's about extents. I don't think altering the frequency or restrictions of the old ways a bit jumps the design straight to the extreme.
While that would be alleviating, I still find myself being concerned. Even though I did not and do not find myself constantly leaning on spells like Protection from Magical Weapons or Absolute Immunity, this dynamic changes when you have to recasting your protections every battle. Rather than bathing the screen in fire, ice, mind-effects, etc. at the beginning of combat, I would have to be more reserved. There is a MASSIVE strategic difference between casting an offensive spell like Confusion in the first round, rather than the third. This is especially true when friendly fire exists, which we know is in.
It's true that the dynamic is changed, but, I can't help but look at how the rest of the design can support this. I mean, in a game with pre-combat buffing, that whole "doing this in the first turn versus doing this in the third turn" tradeoff gets completely circumvented by buffs. The only remaining tradeoff is between what you DO buff up with, and what you don't, and/or what you memorized/prepared and what you didn't. It doesn't matter when you buff, or what you cast first, or how the enemy is moving, or who they're targeting. The only significance to the effects is their rock-paper-scissors effect against the potential effects in your enemies' arsenal. That's not bad that those effects exist, but it's mildly bad when they're the
only function of those effects. Even if you're just really close to that being the only function (you still get the occasional shorter-term effects in D&D buffs that you can't just use as a pre-combat blanket o' bonus), it's still not really taking advantage of the tactical aspect of combat (which I realize wasn't as huge of a focus in D&D combat, but apparently will be in PoE combat, and I don't think this is a bad thing.)
With buffs only in-combat, prioritization and pertinence are significant factors in your buffing. You actually can still scout out the enemy, remaining undetected, see what you're up against, then prepare a buffing plan to start combat with. I would imagine that, since you can't cast buffs "before combat," that casting a buff constitutes the beginning of combat. And, while I'd like to know more specifics on that from Team Eternity, it would seem that, at the very
least, you get to write-off the cast-time on that first buff (with potentially multiple party members each casting something/using an ability, side-by-side in that same amount of time) before the enemy even gets to react. So, it's really kind of functioning as a "you only get one effect 'before combat'." If it works like that. I think it
could work like that, and hope it does, in the interest of not having to have enemies charging you just to cast a buff.
But, if you scout the enemy, and they're using magic weapons, and or are using ranged weapons, etc, and the first thing you do to start combat is cast "Protection from Magic Weapons" and/or "Protection from Missiles," then you've just given yourself a very strategic advantage. After that, depending on how things start to play out, you can either go for another buff, or take some other action (offensive spell, repositioning, save your spells and just use your wand Blast, etc.). That's the beauty of tactics. Yes, it's not as pleasant as just being able to prepare as many beneficial effects as you'd like beforehand, but I think it makes the buffs more meaningful. That's the main thing I like about this whole "no pre-combat buffing." I can look and see that my Fighter did, indeed, occupy the attention of three foes in melee combat, and that they're all trying to knock him down or something, and decide to cast (with my safe-for-the-time-being Wizard) some kind of immunity to knockdown spell or something, on my Fighter.
Personally, I find that more pleasing and rewarding than simply making sure my Fighter has immunity to knockdown (or resistance, at least... the point isn't that it's full immunity... it was just an example) on him for 8 hours of every day, just in case we come across things that would want to knock him down in any combat encounter.
Sure, you have to re-cast stuff every combat, but, I think if the same set of buffs is equally beneficial in 7 combats in a row, the encounter design's a bit lacking in variety, already, to be honest.
So, yeah, in conclusion, I totally get the desire to be able to stack buffs in preparation for combat, and have more ongoing beneficial effects in place for longer than just one fight. But, at the same time, I don't really think that's doing much other than detracting from the active tactics of combat.
Why is the Wizard/caster more fragile in the first place, if the game's just going to let you cast "Compensate for Fragility" on him and let it persist plenty long enough to simply all-but-negate the distinction of his being more fragile than the other classes, 90% of the time?
Having combat-only buffing doesn't automatically make everything perfect, but I think it definitely can bring a lot to the table, in place of what little it's taking away. I don't see it as removing preparation; rather, I see it as making preparation more active and significant than passive (stack the benefits you want, then roll with combat).