Neverwinter Nights 2 and BG2 had 9th level spells in a real time with pause game and it worked fine. So it is totally doable, especially since BG3 is turn based.
just because you add spells doesnt mean you need to add ALL spells, not every spell is available levels 1-9 in BG3. We just dont need to add in things like Wish.
Just have it give you the ability to cast any spell. It's the basic ability of Wish and the only thing that won't make you roll percentiles to see if you lose access to the spell forever.
I'm fine with it being unbalanced like Throne of Bhaal was, where the only people who stood a chance against you were other children of Bhaal. That was a blast and a unique experience for a crpg with some really cool powers.
Imo it shouldn't be balanced. But there has to be buildup in the story and ToB had two full games of it.
No, they can, they just have to accept that it isn't supposed to be a balanced experience in the first place. It was an absolute blast in throne of Bhaal. They would need a story that actually justifies it though.
Also, is anyone actually "bitching" about it? people just want more bg3 with their character and who can blame them for that?
Just to be technical, here... Those past games, BG1 and BG2, utilized a very different ruleset (the ADND ruleset, if I recall correctly) to the ruleset BG3 utilized (5e). While they share a lineage, ADND and 5e are quite different.
It's a game. The fact that they use 5e for most things, doesn't mean they can't include other rules or explanations. A wish spell might not even exist in this universe, and it would be fine. Revivify scrolls don't exist and don't work this way in 5e. There are no "surfaces" in 5e like they exist in bg3. A lot of feats are changed (so far as to even break bounded accuracy). They could easily implement lvl20, but they decided to end the game around 12, which is fair. Let's not act as if they had no choice though
Easily implemented level 20? Most tabletop game masters can't implement a level 20 game without the limitations of a video game. They invariably wind up cartoonish, broken, and unbalanced. There is a reason there is only one official adventure that even ranges up to 20. Balance may not matter to you but It does matter for a game.