Originally posted on /r/FriendsOfBaldursGate.
I'll come out of the closet and admit it: I'm a rules lawyer. I'd like BG to adhere as strictly as possible to the AD&D rules found in the manuals. Why? Well, if it's an AD&D game I expect it to follow the rules. House rules are fine when they serve the story, or if you need unique monsters or characters, but they just get on my nerves when they are gratuitous.
Now, I know there is no time for Overhaul Games to re-work the entire engine in order to make it completely P&P and that's fine, so long as compatibility with mods that do is retained (aTWEAKS being the most notable example, together with Rogue Rebalancing and P&P Celestials; other mods like BG2 Fixpack and BG2 Tweakpack also have a few P&P components).
There is, however, one thing that necessarily requires .exe hacking to implement because it's hard-coded: full benefits for high INT and WIS scores.
I know this is not likely to have a huge impact for most characters, but CHARNAME is given the possibility to reach a WIS score of 23 without cheating and they should have more than just a few bonus divine spells to show it. Besides, creatures whose INT and WIS score was beyond 18 should also have the same benefits (namely, immunity to certain spells as per the Player's Handbook).
Either implement it or make it soft-coded so that modders could easily take care of it.