A little algebra can help us to find the difference (X) between BG3 and BG2. First, let's switch to a more common notation:

X = BG3 - BG2 --> X = (3 * BG) - (2 * BG)

Then some simple factoring will give us our answer:

X = (3-2) * BG
X = (1) * BG
X = BG

So, the difference between Baldur's Gate 3 and Baldur's Gate 2 is Baldur's Gate.