Last week I sat down and watched all 3 Lord of the Rings movies over again. For the record I like them, but don't love them. Good movies, but not good interpretations of the books, though they are probably the best anyone could ever do. Nothing against Peter Jackson; his version of King Kong is one of my favorite movies ever.
The scenes in Moria reminded me how much I loved that chapter in the book. It struck me as funny that with so much of the OSR's attention focused on megadungeons and literary influences there hasn't been more discussion on Moria. From what I can gather, there have been a few RPG products focused on Moria, but the ones I have seen have done marginal jobs. I.C.E. did an ok job with their Moria sourcebook for MERP and Rolemaster (I'll do a full review on it later). I haven't seen decipher's sourcebook for their LotR RPG, but from what I have heard it has received mixed reviews. GW's Kazad-dum sourcebook for the LotR miniatures game has a nice side-view map, which is much different from I.C.E.'s, but other than that it doesn't offer much other than lovely pictures.
I never thought of Middle Earth as a good RPG setting, mostly because I feel that there is no good way to simulate the way magic works that world. I also felt that adventurers seemed out of place in Tolkien's world. But when I think of Moria as a megadundgeon, I think it serves as a great model for creating others. First it provides a real, sensible reason for the existence of the original structure. In this case, we have a valuable mine and an attached underground city, all created by Dwarves. Secondly, we a good reason why the structure was abandoned, namely the release of the Balrog. This also serves to explain why the goblins and other creatures have come to live in Moria. Third, there is built in treasure. The Mithril and other precious metals would be reason enough to venture into Moria, but there could also be many other valuable items left there by the Dwarves. Lastly Moria is Huge. Like the size of Manhattan huge. According to I.C.E.'s sourcebook, it is almost 28 miles from east to west, and in places the mines are several hundred if not several thousand feet deep. As far as any RPG campaign would be concerned, it's endless.
Beyond my reservations about the Middle-Earth setting, Moria has some other issues. First, it is extremely dangerous. The inhabitants are fairly well organized, and led by an extremely powerful demon that seems to like to make appearances at the front gate if someone so much as drops a pin in the foyer. This is not the sort of place where characters would start their adventuring careers. Also there does not seem to be good location nearby to establish a base camp. Setting the adventure in the 4th age after the Balrog has been defeat solves part of the first problem, but Moria would still remain an intimidating dungeon.
I'd like to see some other people's takes on Moria. For me it remains THE iconic fantasy dungeon, and one we can still learn from.