Arx Fatalis is free on Bethesda launcher:
Click on the join Arkane Outsiders
“Join Arkane Outsiders to receive “The Art of Arkane” digital art book free! PLUS, between May 28-May 31 (10am EST), email subscribers get Arx Fatalis (PC) as an additional bonus - Check the box below to subscribe! Be the first to be notified about potential beta access and receive sneak peeks at upcoming games. Sign up now as the Arx Fatalis offer expires on May 31.”