Definitely Solasta-esque prompt reaction system. Although maybe make the pop ups less windows 95 spreadshead and make it a bit more visually appealing than aforementioned title (granted budget limitations are a thing). You need some control over your reactions as to decide if to let something pass or not. I mean, I wouldn't waste my spell shield on sacred flame every time. But on higher damage spells it is definitely a thing. Pop up reaction should work fine in BG 3 as it is after all, a turnbased game. And having the option to have your party respond with a readied attack, cantrip or ranged attack would be welcome as well. Makes it possible to lay in wait and such.
A little off topic, but also allow wall of flame (not sure if you can) to be cast in either wall, outer ring or inner ring mode, that way defensive turtling is possible in melee heavy encounters and such. As for the abundance of concentration spells, that is a 5e thing unfortunately. They wanted to do away with doomstacking your mage with stuff like globe of invulnerability, protection from energy, protection from evil, blur, mirror image, mage armour etc before each fight I expect. And no I am currently unaware which ofthese is supposed to be concentration or not. I know blur and mirror image are duration based but I am not sure if that is how they work in 5e or not. Solasta has blur as a concentration spell, but I do not know how much is homebrew in this case. Could be that Solasta homebrewed it, or BG3 can anyone elaborate?
