I've not found anything in BG3 harder than Kangaxx, the Beholder lair or the Irenicus fights. Kangaxx I simply could not beat until I read up some hints and tricks.
Sure, you're going to get party-wiped, or at least have a lot of resources depleted, the first time you come across some of these foes. But a little preparation - getting the best possible equipment/AC, taking on allies (familiars, sac spiders, Andrick & Brynna, Sazza, Flind/Rugan, Glut), positioning, potions, spell buffs - makes most of them much smoother. And as another poster mentioned, some encounters are just best left until level 4 (spiders, Gith, Minotaurs, Bulette, Kuo-Tua).
The spiders are a good example. If you wander in blind at level 2 with no prep and without having found the Spiderstep boots, yes, you're probably going to struggle. But go in at level 3 or 4 with all your characters having 18+ AC, the Boots, access to Misty Step, the ring of poison resistance and 2/3 potions of same, then sneak around and kill all the eggs, plop down some candles to light your bows on and a barrel to cast Light on, give Lae'zel a potion of hill giant strength/haste and THEN start the fight, it almost feels too easy.
Last night I was trying to do same and got spotted after killing only one batch of eggs, but still managed to take down the matriarch, the other 2 phase spiders and the spiderlings while total party casualties were 10 damage to Shadowheart and 7 to Wyll.
BG3 plays very differently from 1 and 2. If you want some tips on improving your tactics, try watching a couple of vids by, say, Retcon Raider or WolfheartFPS.
Last edited by Adiktus; 07/03/2102:19 PM. Reason: Added video tip