I guess my megadungeon 'scale' is much larger tha yours... the MEGA connotes to me a truly expansive dungeon system that would take literal days, if not weeks/months, to traverse... it would be somewhat akin to saying: you go into Neverwinter or Sigil with what you got... Make it count... This comment isnt intended to be mean just merely a query concerning what kind of scale you (or 'we') have in mind when we use the word "megadungeon?"
Nope, not mean at all. I understand the question.
I'm running Stonehell dungeon. 15 levels, about 100+ rooms per level. I also add on my own sub-levels and additional mini-dungeons... I'm constantly expanding it.
I think our concept of megadungeon is consistent, but I failed to properly communicate how I approach running one.
A typical session goes like this:
1. Party forms up in town... players buy any equipment they need, hire henchmen or followers. I have about 9 players in my group, but not all of them show every week (although now they can).
2. Party picks a goal or location they intend to focus on. It can be as simple as lets try to find stairs to level 4, or lets investigate that weird statue. The point is that I try to encourage a clear objective.
3. Party delves into the dungeon and explores. I use an explicit procedure for dungeon exploration. X amount of movement or X amount of time spent searching is tracked. This time triggers periodic random encounters.
4. Party explores as far as they are able and I tell the players when there is about 45 minutes remaining in the session.
5. Party uses the remaining time to push out further or exit the dungeon. Once they exit the dungeon, the session is over.
Once back at town, the party gets xp, sells any loot and takes any notes on things discovered for next session.
The point is that the exploration of the dungeon is handled in multiple delves. Each session is about 3 maybe 5 hours of real time and each delve usually is about 4-6 hours of game time. During that delve, short rests are permitted, but long rests are impossible.
Sometimes the session ends while they are still in the dungeon. In this case we stop for the night and pick up from where we left off, next session. I try to discourage that, however. I track time spent in the dungeon. At beyond 8 hours of dungeon exploration, I start requesting Constitution checks for forced march every hour. So, if session 1 they spent 5 game hours in the dungeon, then next session they have 3 more hours of free activity before they start pushing themselves and start taking Exhaustion.
Its like a work day. They delve for a time and then clock out. You don't go to work and then take an 8 hour nap at lunch time. Ha.