> n BG1 there is a simple way to deal with the basilisks: animate dead.
Animate dead is a tier 3 spell. Takes a long time until you get it on BG1.
> - Early in the game you have only a few spells, so it is hard to keep your party healed.
Don't play on hardest difficulties. On low difficulties, you can regain health and cure conditions by just resting. Also, potions are your friend on early game.
For spells, some wizard archetypes gives bombs. Some sorcerers gives a might animal companion, others give spell like abilities early on and Kineticist is a elemental 3.5e warlock which is a quite powerful class.
> it would have been useful to learn a different spell at the last level up some hours ago.
If you are a novice, play as a prepared caster, not as a spontaneous caster.
> you have to get over a giant mountain of frustration before you can start having fun.
Or lower the difficulty.
I tried to solo IWD without knowing anything about 2e.
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Anyway, BG3 will gonna be 5e and low level. 5e is far easier to learn and more streamlined. You will not have to face demigods on BG3.