Changes the player's current dungeon difficulty.
- 1 → 5 Player
- 2 → 5 Player (Heroic)
- 8 → Challenge Mode
When the change occurs, a message will be displayed in the default chat frame.
The above arguments are also returned from GetDungeonDifficultyID().
Patch 5.0.4 (2012-08-28): Renamed from SetDungeonDifficulty(difficultyIndex). Challenge Mode added to index.
Patch 3.2.0 (2009-08-04): "3 → Epic" removed from index. Related function added: SetRaidDifficulty(difficultyIndex).