At what point should you consider an area too large, in terms of dimension? I know that adding clutter and actors will increase the size of the area and I don't want to overdo a single area with too many rooms and halls.

"Too big" is subjective. I plan on having a couple dungeons that will take 1+ hours--but it is "too big" when the dungeon no longer makes sense. If you defeat the boss 10 minutes in, and there is content for an hour behind that...but no real reward...that is too long.

I was asking more in a technical sense, as in the area eats up so much memory that it hinders performance.

I think it is a matter of personal taste. As a player, I don't worry about how many rooms a dungeon may have. But it does annoy me if a dungeon (or any other type of interior) has a bunch of rooms that exist for no other purpose than having yet another room.

I would suggest thinking about what goes on in the place you are designing. Build only the rooms that contribute to the purpose of the place. take a minimalist approach to your core design of the area. Once you have it all in place, then go back and build extra rooms, but make sure they sort of relate to what the rest of the place is about.

The Project I'm about to get into will have me designing some new interiors. If I am going to do something like put guards who are unique to a location, I must answer a couple of questions:

How many shifts will there be. If there are 3 shifts, I need to make sure that there is a barracks associated with the place, and there are enough cots for 1/3 of the total number of guards, enough tables for another 1/3 of the total number. the remaining 1/3 will either be patroling or standing guard. I'd give them schedules to make sure the shift rotates at the correct times. 1/3 of them will be sleeping. 1/3 will be off duty sitting around in the baracks or wandering around the general area. While this is not necessary for a functional mod, I like details that make things feel alive.

That's just how I roll.

I'd like to do a dungeon crawl sort of a thing. A lot of exploration and encounters. I'm new to modding..done a bit of messing around in the Oblivion and Morrowind CS, but nothing more heavy than a house or small temple settings.

I don't know squat about scripting, so making a DnD type "dungeon" with quests/dialogs/special encounters is probably a ways down the long road.

Ah...

Well, That is an easier question... Break your dungeon up into areas of functionality. Make each big enough for details that flesh out that functionality. Separate them with closed doors which are area transitions. A short load screen never really hurts anything.

If you are doing a multi-floored interior, keep each floor as separate interior cells. Unless your interior is pretty small, like a house or something. The more your interior sprawls out and is filled with detail objects the more your mod will require in terms of resources.

I'd say break your cells down into areas that you could logically see. A core area and some attached areas. But anything beyond that, put in different cells. Does that make sense?

You should be able to get a rough idea of scale by looking over existing multi-cell dungeons in the base game. As a rule of thumb, 5-10 "rooms" of a typical dungeon is usually a good number before beginning a new cell. Load doors can be a useful narrative and pacing device, so keep this in mind.

One technique some level designers here use is to build your dungeon layout - even a very large one - in a single cell, then cut it into smaller cells once the overall pacing and layout have been established. It's all a matter of preference.

When modding, it's important to remember that players with very high-end and very low-end PCs will both be playing your dungeon - so it's usually best to err on the conservative side.

My opinion here.
You can make it as big as you want. IF you use room bounds. What they do is only allow the area bounded by the room bounds to be loaded. What this does to my understanding is only load the section and 'render' the section that the player is currently in. This really improves performance, even on slower computers.

One thing though, if you go outside the 'usuable' X,Y area of a cell, it can cause all your object to be jerked to the 0.0 location into one big messy pile.

Thanks very much.

That's a pretty good idea, I'll do that.


What's the best indicator that the cell has too much stuff in it? I'd suspect low FPS on entering the cell?

low fps, long load times, possibly even crashes if you really overdo it.
When you cut and paste a chunk of a dungeon into a new cell, it should keep reference linking and script property references and all that juicy goodness, right? So the only cleanup you have to do is put the loaddoors in and maybe set up a new navmesh?