I've been playing Realms of Despair for about seven years now, having attempted to quit once or twice without success.
This MUD really does have something for everyone, whatever their taste. Numerous global channels, and hundreds of players, mean that there's always lots of people to socialise with, and an extensive Guild, Order, Clan, Nation and Council system (each with their own chat channels and Headquarters) can add both intrigue and depth to the social structure.
The number of players also means that while the MUD can be an intimidating place for a new player, there are always lots of people on hand to help out and guide newbies. While it can take a while to get to grips with the game, it soon becomes very absorbing.
The MUD has countless of originally (and extremely well designed) areas. Many of these aren't restricted to avatar (Level 50) characters and can be explored by lower-level characters. The depth of some of these areas (in particular newer ones, such as Nevermore, The Mountain of Lost Souls and the Haven of Everlasting Light is astounding, with numerous within-area quests that require intelligence, skill, and lateral-thinking to complete. This makes the MUD perfect for players who love to explore and solve puzzles.
The numerous areas also mean that mobkill on the Realms of Despair is incredibly varied and challenging. As players work their way up towards the more difficult mobs, more and more teamwork is required, and subtle technque a must. The premiere mobs of the MUD such as Lord Seth, Merlin, Satan and Divine Retribution can require days of planning, up to seven or eight experienced players and great skill to defeat successfuly.
Player-kill is also very active on the MUD, though it's something I rarely indulge in. 'Deadly' players are devoted to pkill, and are always a target whichever area they happen to be in, and may loot equipment from the corpses of their enemies, while 'Peaceful' characters cannot pkill unless they enter the arena.
RoD is the home of the SMAUG codebase, and as such contains numerous and widespread advances over any other SMAUG muds you may have played. New classes, numerous new areas, lots of different spells and skills to name but a few. SMAUG 2.1 was installed at 'The Shattering' a few years ago, and there are still secrets since then that have not been uncovered...