There won't be a BG4 no matter how well BG3 does, because the BG story is as done as it can possibly be.
Story was done as it can possibly be after Throne of Bhaal and that didn't stop them
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True enough, but that's exactly why I'm pretty confident about no BG4, because BG3 (the name, not the game) was such a hard sell already such that BG4 (again, the name) would be too much of a stretch. Besides, I can't see either Larian or WotC even wanting to use the "BG" name for yet another game. They've got their name-recognition/nostalgia mileage out of BG3, and I'd guess pretty much exhausted it. It just makes sense for them both to agree on launching an entirely new franchise, and very possibly using a setting other than FR.
