Dungeons And Dragons Online: DDO News: Making Dungeons

When asked why it's hard or impossible for user submitted dungeons to make it in game, Keeper elaborates a bit in response, and includes a brief look at what goes into making dungeons:

I'm sure the next question will be, "Then why not tell us what art assets are available and how they work?" The answer to that is that it's difficult enough getting the artists and the designers here in the same room to coordinate that well. ;-) I would have a terrible time explaining the dos and don'ts of how to build a jungle or an m-room** to someone who had never seen the individual pieces.

*Dungeon sets are a bit like legos: lots of interlocking pieces that can be used to construct spaces ranging from rather small to quite large and complex.

**A single dungeon room, potentially quite complex, made of multiple floor, wall, and ceiling pieces.

While the post does have the above, it looks more at the complexities of converting a PnP creation to MMORPG, such as the creation of art and working with physics models.