But if the game would go to level 20 the sorc would have enough different spells. At the beginning the spell of the sorc are very limeted but he can have more than 2 different spells per spell level. Have to mention the end of NWN2 where at the final dungeon resting was not possilble. Here the wizzard had serious problems and socerer was the bette choice because he could cast the good spells more often.
But if you compare Sorc / wizard to a freaking fighter multiclass it seems to me that the arcanic classes are weaker?
Well. here in lies the problem with crpg campaigns. They offer a limited setting with far less different situations to handle than a tt session can. So, in crpgs, the sorcerer comes on top. But, that can be fixed with Larian being an amazing DM, putting in an abundance of situations where those situational spells that a sorcerer would rarely choose, will come in handy.
And yes, the whole point of multiclassing is to make characters that are far superior and more interesting than the original classes. That's why they are so popular.
You seem to forget that it works both ways. A fighter can multiclass into a caster. A caster can just as easily multiclass into a fighter.
Also, I haven't actually seen any conformation from Larian that multiclassing will be incorporated in BG3. Or what our max clvl will be. Multiclassing means giving up progression in our current class and for casters that can be disastrous not having enough clvls to compensate for giving up spell progression.
Take for example the sorcerer. At clvl 9 she learns her first level 5 spell. At lvl 10, she gains her third metamagic feat. If max clvl is 10 then that means that for her to multiclass she has to give up a metamagic feat and possibly that 5th lvl spell to gain levels in another class.
Atleast that is how it works in 3.5. Niara, does multiclassing still work the same way in 5e?
