When BG1 and BG2 came out. They were limited by the number of levels they had at first. They were increased by expansions.
The BG1 EE and BG2 EE are combining the game with all expansions into one. Thus you don't see the split in levels of the games.
There doesn't need to be a BG4...Just an expansion.
BG1 Level 8 cap
BG1 Expansion Level 10 cap
BG2 Level 20 cap
BG2 Expansion Level 40 cap.
And nonhuman races were limited on how high in a class they could reach.
