From Terrasphere
Preface
On Terrasphere, Dungeon Masters, or DM for short are the site's storytellers. DM's often runs in-character events that tie into the main storyline or taking players through a personal story or dungeon they came up with. DM's essentially plays as the world the player inhabits, determining the effects and consequences the player's actions have on their surroundings and NPCs.
Each Dungeon Master have their own page on the wiki that gives a more detailed look at their style. Not all DM's fit the style of their players, so make sure you learn which DM you are most compatible with in case you decide to try your hand at a DM'ed / Challenge thread.