{Disclaimer, I'm using a PS2 emulator. There's a chance this bug won't work on console}

I'm still experimenting with this bug, and as of right now I haven't found anything useful to do while OOB, but I figured I'd post about it in case anyone else had some insight.

Where I was performing this bug: Just after the first of the three gates in Sewers 2

I would run into to wall beside the open gate (as if trying to run into the save point) and add a second character. The Character (I was using Elf) would appear on top of the map.

Then, if you jump and, at the peak of your jump, move Up (in the direction of the door) you can clip back onto the roof proper.(note: It's a very precise angle you have to hit. If you it it off you will either end up back in the room (on top of P1 basically) or near the save point.) Once there you can move around, but (at least, as far as I could tell) cannot get back in bounds.

If, once OOB, you use P1 to recall, then once back at the tavern, Go to character select and remove P1 (making the elf P1), and then attempt to Recall. The recall should fail, and then once you enter a load zone (Either Baldur's Gate or The Cellar) you will be OOB (and unable to see yourself)

When OOB movement is finicky, and there are many dead zones where if you touch them you will become unable to move. As of right now I cannot find a way to get back in bounds.

You should test this on dolphin since that emulator is very accurate if you don't have any actual copies of the game.

I do have an actual copy, but I need time to set it up. Haven't used my PS2 in years

I'll test on dolphin in the meantime though, planning on experimenting more tomorrow

On dolphin I have found the bug still works, and I've found that, using it, you can enter the Cellar without needing to get the key from Ethon. I don't think it's faster, because talking to Ethon doesn't take that long, but it shows that this bug could have applications.

If you create a second player while running into the wall behind Bartley, that player can run on top of the walls into the back room, and activate the transition into the basement.