Mizal asked me to create a thread back on Tuesday, so I of course obeyed immediately. Fortunately, she didn't specify it had to have a good title, else I'd fail at that too. Beware, lots of scary text ahead.
MUDs, or multi-user dungeons/dimensions/domains/dialogs (yup, there's a fuckload of definitions) are similar to interactive fiction. You progress by using text commands, like east, give soul to EndMaster, backstab noob and so on. But unlike interactive fiction, they're online, real-time, have a bunch of RPG elements like quests, battles ... I guess they're not so similar to IF after all.
The most popular genre is of course fantasy, but you can also find MUDs that are set in a science fiction modern, historical, steampunk, or other setting. They also differ quite a lot in what the main focus is; hack and slash, exploration, crafting, room creation, player interaction, roll play, so on.
My favorite MUD is Alter Aeon. It's set in a fantasy setting, so of course during character creation you get to pick from the standard classes: warrior, thief, mage, cleric, necromancer, druid. No races unfortunately, you can only be a boring human. What's interesting about its class system is that you don't just pick one class and stick with it. Every 5 levels you get to pick another class, so eventually you'll have levels in all of them. It might seem confusing at first, but when you understand the game enough, you'll be able to make some pretty powerful combos.
It's a pretty active MUD, with a friendly playerbase and almost daily updates. The focus is primarily on solving quests by killing mobs and finding items, but it tries to be welcoming for everyone. The world is large, and rooms have decently detailed descriptions, so it's fun to explore. A lot of crafting skills have been added recently, and while many aren't worth the effort, some can produce very strong equipment if you're patient enough. And if you hate playing solo, you could participate in the arena, or join a group to make getting exp easier; some high level areas are even specifically beatable only in groups.
If you want to learn more, check out their website. There's a guide or help file for everything you ever needed to know, and many things you didn't. But if that's not enough and you're still confused, just ask! :)
How about you? Does anyone here play a MUD anymore? I have a feeling this won't be a very active thread ...