The Elder Scrolls V: Skyrim is a fantasy action RPG set in Skyrim, a northern province of Tamriel. Gameplay focuses on exploration, combat, character progression, and interaction with other characters. Players take the role of an unknown prisoner who must learn his or her heritage and save the world of Tamriel from Alduin, the Nordic god of destruction. Character creation and progression use skill trees and abilities called 'perks' instead of character classes. The Elder Scrolls V: Skyrim features a character AI system called 'Radiant Story,' which gives non-player characters the ability to interact with the environment and give randomized, customized quests to players.