The turn based combat system that I really fell in love with, but that is now quite antiquated was the Knights of the Old Republic series. I would put these in the list of my top 5 favorite games of all time. I have played them both through many times, and they remain at the top of my list for favorite world building / lore additions from any IP. If there is any similarity between BG3 systems, and KOTOR then I imagine I will feel right at home!