For old school players, the World of Greyhawk hardly needs description. This was the birthplace an origin of many monsters, heroes and places that are now as common as household words-- Mordenkainen, Bigby, Tenser, Rary, Iuz the Old, Vecna, Tharizdun, and more. Players will find themselves in the hotbed of the central Flanaess, and will find such places as The Free City of Greyhawk, The Wild Coast, The Abbor Alz and Bright Desert, The Shield Lands, The Gnarley Forest, Village of Hommlet, The Horned Lands, White Plume Mountain, Against the Giants, The Ghost Tower of Inverness, and possibly the most challenging dungeon in the NWN multiverse-- Undermountain, with more on the way. There are many quests, some of which place the world itself in jeopardy. It is low to mid-magic, with some minor environmental factors to consider.
The World of Greyhawk can be a hostile environment, and it is not for the novice player. There are traps, puzzles, obstacles, in addition to rare and dangerous creatures. The not so rare & not so dangerous critters are also pretty dangerous here. :-)
There are also multiple crafting options, character editors, and Bard Studios for bard characters to create their own lyrics or their songs. There are searchable libraries, intrigues, plots, villains, evil cults, and other things that go bump in the night. One can play from Level 1 to Level 40 on this server and then do it again with a different character and adventure in completely different areas unseen by the former character.