Great responses thus far, so thank you for them.
I'm quite curious as to how this kind of thing will be tracked in BG3. BG1/2 had the reputation system, which served its purpose well enough, but wasn't quite good enough. I mean my approach when playing an evil character (generally) is not psychotic but a more intelligent, calculating evil. So I would complete many quests in the "good" vein to increase reputation, so NPCs like me and trust me, at which point I can abuse that trust and make use of it when the time comes (which in BG1/2 basically translates to Evil Points...how much reputation I can burn in order to choose an evil option without the world turning hostile). There's one evil option I very much enjoy in BG2....and that's giving the silver dragon eggs to the demon yourself. So, you go through the Ust Natha bits using the "good" path, until such time as you have the real eggs and the drow have the fakes....let them get blasted, then treat with the demon yourself and give it the eggs.
The big draw back is the evil party members will leave if your reputation gets too high...as there is no option to explain your motives. To reassure them or explain to them that, "Hey, I'm as evil as they come...patience. We earn that trust. We lull them into security...then, they're ours! We will use that when needed and do what we want to do. We can frame whomever we want! Cast the blame elsewhere! Have them help us conceal/destroy the evidence...then, if they show signs they will be unable to live with the deeds asked of them and expose us...well, we help end their doubt and guilt, by ending them. No loose ends."
Anyhoo lol...I do hope the evil options in BG3 go beyond Stupid Evil.
