Reputation may also affect a characters ability to participate in dungeon raids. Where the concept of “attunments” (the act of earning access to dungeons) has long been a part of the game, some attunments are tied to reputation. The Burning Crusade introduced “heroic difficulty” mode for some 5-man dungeons, with an attunment requirement of Revered. Upon reaching Revered, players may purchase a key to “unlock” heroic dungeons. [6] Naxx was introduced with a varying attunment requirement; the higher the players reputation, the less it cost for attunement.