Some successful lines were the result of improvisation.
Recently, Jennifer English, who voiced Shadowheart in Baldur's Gate 3, spoke with Radio Times and shared her memories of working on the character.
As it turned out, one of the lines was a joke by the actress, but Larian really liked it:
One of my favorite moments in Baldur's Gate 3 is when Shadowheart talks about Night Orchids [...] Then I decided to joke and added to the line during the recording: "Just kidding!", imitating gunshots with my fingers. I was sure that it wouldn't make it into the game, but in the end, this scene remained.