I'm thinking of creating a multi-level dungeon, or rather, multi instanced I suppose it would be. Would it be better to create a new worldspace and have all of the dungeons levels in that, or put them in an existing worldspace.

Also, would it be considered bad practice to make multiple levels in one cell? In other words: separate from each other visually and just making the door port the player to a different section of the cell.

A Worldspace is an exterior cell that is technically separated from Skyrim's main wilderness either for performance reasons (e.g. cities) or because it actually is a different world (e.g. Blackreach, Azura's Star, Sanguine's domain)

Most dungeons would be made from tiles in interior cells. For a large dungeon there are a few things to consider:

1. Performance hits: if your dungeon is well filled, it may become very slow sooner or later, but there are optimization methods that allow you to fade out everything the player currently can't see. http://www.creationkit.com/Bethesda_Tutorial_Optimization

2. Loosing track: A large dungeon with multiple overlapping tunnels can become very confusing for the builder, so it might be better to split it into several cells.

3. Different atmosphere. While there may be a bit of daylight shining trough near the entrance, the deepest halls of your dungeon may be pitch black or everything may have an eerie demonic glow, you also may want to have water on different levels of the dungeon, or even play a different music when you get close to the ancient evil that dwells deep beneath. For all those cases you need different interior cells, because there can be only one such setting in each cell.


As for bad practice, it really depends. If you want to make an old-school teleporter/spinning-floor maze, then I'd say it is a good idea to have everything in the same cell (no loading screen). And of course it's fine to avoid the loading screen when the player falls into a bottomless pit, that can be only exited using a teleporer. Like everything it shouldn't be overdone, though. And there may be alternatives to consider, a well-done custom loading screen may add to the suspense, especially when you give a hint of what awaits the player down below.

When keeping track of your dungeon layout is the main reason for separating your dungeon, then you can just as well make separate cells and claim it was for performance reasons.

Performance isn't really a concern as I've read through and understand the optimization details. I am familiar with vizual blockers from creating maps for Counter Strike, this is the same basic concept only we're telling the game where to look in certain cases instead of worrying about it only drawing to the nearest wall.

Complexity I'm not worried about. By the time my classmates were figuring out how to make cubes and pyramids out of construction paper, I was trying to figure out the most complex shape I could get out of one sheet of paper. As I grew older, I used CAD programs to design some buildings for school projects. I enjoy making things fit together the way i see them in my mind, I just need to know if the CK can handle it.

I was already aware of the design portion of it. I already had different areas planned out, but for each area there will be multiple sub sections, say, 2 or 3 for each area. I plan on each area having it's own cell, but would I need to have each subsection in a new cell, or could I just port a player around a cell and have all the subsection for one section in the same cell. As you stated, some dungeons have their own worldspace. I just want to know where the cutoff is that I should start thinking "Hey, this this is really big. Maybe I should put it under something else."

Deciding whether to use a worldspace (= exterior cells) or an interior cell for a dungeon is rather simple:

If you want to make a wide open underground cave then use a worldspace.

If you want to make narrow tunnels you need to use tiles and *should* use an interior cell.

You *can* use interior tiles in a worldspace of course to seamlessly transist between a tunnel and a huge cave, but it's really a pain to cover the gaps at the junction and even more so to cover the interior tiles so that the player can't see them in third person mode.

Ok that answers it. I may have to go back and forth depending on what i'm trying to acomplish for some projects but for a pretty basic dungeon crawl interior cells will do. Thanks for the answer.