[Molly]

I obviously prefer a Mud type where zones and descriptions are important, as well as depth in the zones, since that is where Builder skills are required. This probably rules out pure PK and pure hack'n'slash. Roleplay Muds usually look for depth and quality, but my favourite Mud would be focused on exploring and questing, like the one that one I build for presently. Designing quests is one of the more fun tasks you can do as a Builder.

I like change, so I do all kinds of zones, anything else would soon bore me to death. I prefer working on pretty dense surroundings with lots of extra descs and secrets embedded in the rooms, but the building style obviously needs to adapt to the type of area you work on. For instance the room descs in travel areas would be much shorter than the ones inside a house or a castle, where you would put a lot of depth and extra descs. I am not saying that extra descs would not bee good in a forest or grassland too, only that somewhere you have to make a choice between quality and quantity. If every room in the Mud would have lots of extra descs, you'd probably end up with a very small world.

I think 4-8 lines are ideal, too short looks puny, too long gets spammy and just makes players turn on brief mode. It's better to put everything above 8 lines into extra descs. (Although I must confess I sometimes break my own rules here. I often get carried away while writing, and my descs become too long). Pure travel areas can have shorter descs, but not less than 2 lines.

Race, alignment and such details don't matter to me. What does matter is if I can make the mob interesting in some way, give it some sort of background history, or make it an integrated part of a quest or the overall plot of the zone.

One thing that is essential to me is that the Mud has DG_scripts, or the equivalent, and that the scripting code is kept updated. Scripts is what makes a zone come to life.
Generally I'd say the more tools us builders can get, the better. We don't HAVE to use them all, but they should be available when we do.
And I want access to ALL the tools. I hate the system some muds have, where you first only get access to room edit, then possibly to mobs, and finally objects and scripts. Some muds even only let a small set of trusted builders work with the mobs and objects, while the main part are supposed to just fork out room descs. To me that is slave labour, and I'd never build in a place like that. All parts of a zone need to work together, rooms, mobs, objects and scripts, and you have to work with them as a whole to get good results.
Whether you like to work in OLC, with an off-line building program or directly in the files, like I do myself is a matter of personal preference, but it's nice if the Mud can offer alternatives.

Personally I wouldn't like building for a Mud that is based on a book or a series of books, it would put way too much restraint on my creativity. I am also growing increasingly tired of medieval fantasy, even though that was my first preference when I started building many years ago. I like to have SOME sort of consistent theme though, since having a sort of platform to start out from makes building easier. Nowadays I love to indulge in Ancient Greece and Egypt - the combination of historical facts and myths give enough foundation for my fantasy to spin off.

I think the Mud must have some building rules, as long as they are sensible ones. Consistency is important; ideally the player should not even notice when they pass from one zone to another. If every Builder gets to follow their own taste, you'll end up with a total patchwork. You also need to have rules about the balancing of mobs and objects, or you'll end up with a steadily escalating set of addaffects and other stats on objects, since that is the easiest way for Builders to attract players to their zone. And finally there needs to be rules about the use of colour, unless you want the Mud to end up looking like a badly decorated christmas tree. (see below)

Personally I like colour in a mud, when used tastefully, consequently and not to the excess. I think colours in general should not be left to the builders to choose however, with the exception of small highlights here and there. The colour scheme should be part of the Mud design and built into the code. Rightly used colours help with the readability, and consequently with the playability of the Mud. For instance different colour on room names, room descs, exits, mobs and objects all make it easier to get a quick grasp of the room you enter, and different colours on channel makes it easier to single out important messages from the rest. Above that, colour should be used sparsely.

I can see how it would be more fun to build for a new and upcoming mud, where you have a real chance to put your mark on the game. However, for me stability and consistency is everything. I would absolutely hate to put months of my work into a mud, only to see it fold before it even opened. So if I ever went on the lookout for a new Mud to build on - (which seems unlikely) - I'd probably go for an established Mud, unless the new Mud was run by people I knew well enough to trust that they'd carry out their project.

Most important of all to me is an environment where Builders' rights and skills are acknowledged and respected.
Also it is important that the coders in the mud really listen to the builders and provide them with all the tools they need to do a good job.