Larian concept of act is narrative, the fact that is match maps is more of a coincidence (in DOS2, act 2 has two maps: Reaper's Cove and Nameless Isle, In the Dragon Knight Saga, act 1 is 2 maps too).
They always have 3 of them: beginning (setting the stage), middle (development) and ending (conclusion). Act 2 is always the largest map and content. The ending is the smallest one. Act 1 often feels like its own story, as you get hints about the larger story but the focus is on more mundane things. There is usually a "transformation" at the end of Act 1, in the sense that your character is called to "greater" purposes by the conclusion of the first act.
Currently, BG3 act 1 is about removing the tadpole, which we cannot complete because we have to go to another inaccessible map to have more information/answers/get it done. Regardless if we get to remove it (or disable it), that story thread will end with Act 1 and Act 2 will have a new story focus.
I expect Act 2 to be set in Baldur's Gate going by all the NPCs saying "see you soon in BG".
Last edited by azarhal; 17/10/20 12:20 PM.
