The game is called Dungeons and Dragons, right?
The reality is that I’ve run lots of dungeons, and I include very few dragons...
Maybe it’s because I refuse to run dragons as anything but intelligent beings of immense power. Sure, there are rules for little dragons, and on a rare occasion I’ll toss one towards my players, but for the most part, a dragon in my games tends to be a force of nature, not a combat encounter. As such, I tend to hold them back.
I’m thinking that’s a mistake.
In reading other DM’s play reports where the players regularly encounter dragons out in the wilderness (often just a flyby, rather than a combat encounter) it seems that the players don’t just come to think of them as big goblins - aka bags of XP. They still inspire awe and worry, tinged by greed.
In my 4e game, my players have finally encountered a dragon, and they kicked it’s ass! They were psyched! Had it not been a part of the adventure, if I had written the adventure they’re running through, there wouldn’t have been that encounter.
In the back of the 4e DMG there is a kobold lair adventure that wraps up with a white dragon - an adventure for 1st level characters! It’s an adventure that gives exactly what the game says it gives - Dungeons and Dragons. Maybe that’s the right approach?
Now, I don’t want to go crazy and have dragons every other encounter. I still want them rare enough that players don’t just charge right in every time. I want them to pause before even thinking about picking up their dice. However... I think I do want to see more dragons in my game. And more importantly, I think my players want to see more dragons in the game.
How this will work in the megadungeon, I have no idea, and it’s something I need to think about, but the giant chasm certainly allows for at least one dragon, maybe more...