Played a bit longer, and yeah the surface effects are driving me crazy. This absolutely doesn't feel like playing Baldur's Gate/D&D at all. Everything about the combat feels like I'm playing a mod that one guy made for DOS2.
I used Acid Splash on a group of enemies and then sent a melee character to fight. They got tagged with an "Acid" debuff that lowered their AC by 2. I actually exclaimed at my screen because that's.not.how.acid.splash.works. Furthermore, there is no Acid debuff in 5e that lowers your armor class by 2. I'm literally waffling between playing more or hitting the refund button on steam. I wanted Baldur's Gate/5e. If I wanted to play DOS2, I'd load that back up.
This is staggering. I get that one would implement rules in a simpler way by cutting off unnecessary stuff but... I don't get why Larian leaves off some of the 5e key features for the sake of gameplay & simplification (backgrounds being just brushed off, starter kits for classes, uncanny dodge / cunning action for rogue...), and yet manage to INVENT new rules out of nowhere. Like they're starting from scratch instead of using the years of D&D5 playtesting to use the core rules as a whole.
D&D5e was already simplified to prevent the use of modifiers AFTER the die is rolled. Compared to 3e and 3.5e, where you had tons of post-roll modifiers like that acid splash reducing AC or whatever, the main goal of 5e was to bring a nice flow by squishing all modifiers into either advantages or disadvantages.
The spells and abilities now work taking this into account and usually, when a spell or ability (take Fairy Fire for example) grants you an advantage, it means it already deals with this spell's environmental effects to grant you a boon (in this spell case, the advantage coming from the bright light surrounding the creatures inside the area of effect). You don't have to add other bonus/minus on top of this, it's already materialized as an advantage on your throw ! No need to add further surface damage and combos like in Divinity : it's already been taken into consideration by your abilities or spells in D&D5 !
Instead of merging key features from DOS2 and D&D5, Larian should leave them to their respective games : BG3 with little to no surfaces whatsoever and the D&D rules (action economy etc), and DOS3 (whenever this comes out) with action points and surfaces all over.