Oblivion is an action role-playing game (RPG) that incorporates open-ended gameplay. The main quest can be postponed or ignored for as long as the player wishes to explore the expansive game world, follow side-quests, interact with NPCs, slay monsters and develop their character. The player is free to go anywhere in the realm of Cyrodiil at any time while playing the game, even after completing the main quest. The game never ends, and the player may build up the character indefinitely until the level cap is reached. The fast-travel system used in Arena and Daggerfall makes a return in Oblivion. When the player visits a location, it appears as an icon on the game world map, though the player starts with all the main cities unlocked this way. From then on, the player can travel to this location instantly if they are outside and not in combat, though the in-game time is adjusted to reflect the length of the journey. The game regards the player to be in combat when a hostile creature or NPC is near the player, regardless of whether or not the player is aware of the creature or vice-versa