Subscribe to Amazon Prime? Well you can get a free copy of Neverwinter Nights: Enhanced Edition thanks to their partnership with GOG.
A good time to pick it up too considering Beamdog are many years later still upgrading the game. Just recently it had an update adding in a new cartoon shader and lots of optimizations. It's still going strong! It has a Native Linux version available, that Beamdog have supported well too.
How to claim it? Go to Prime Gaming, login with your Amazon account and you'll see it in the list. You'll also need a GOG account as well of course. You have until July 19th to claim it. Since you'll be getting a copy on GOG, you don't need to keep your Prime subscription active - it's yours to keep.