The concept of the ‘underworld’ permeates fantasy roleplaying games, and has since the earliest games as conceived by Dave Arneson. Greg Svenson, one of Arneson’s original players, describes going down into the dungeon under the castle, ‘apparently… abandoned for years by the normal denizens of the castle’. The first area of the castle, a ‘huge irregularly shaped room’, was ‘the only area… that was secure for us good guys.’ After which all logic and sense was abandoned for endless hallways, staircases, improbable creatures with no comprehensible reason for existence, and absurd magical devices and traps.
The adventure ended in failure; the players did not manage to foil the evil wizard, and ended up becoming lost and fleeing the dungeon as best they could. As the game continued into further sessions, Arneson expanded his original designs, and the dungeons grew deeper and more complex. Gygax followed the same pattern; his game featured an endlessly expansive underworld called ‘Castle Greyhawk’, and he suggests in the earliest rules for Dungeons and Dragons that his world had at least two new dungeon levels under construction in the bottom of Greyhawk at any given moment.
These dungeons don’t make sense, practically; both in the world’s setting, where there’s no plausible excuse for their existence, and as settings for a game, where the fiction being emulated had no such physical locale. Conan might go into a cave, but the notion of returning week after week to the same cave, going a little further each time, then retreating to safety: that was entirely alien to Conan, or any of his contemporary fantasy heroes. The ultimate such dungeon in fantasy fiction, Tolkein’s Moria, was still nothing more than a pathway, a temporary side-trek through a particular flavor of danger before returning to the surface world.
But there’s something compelling about them, isn’t there? If the world weren’t in desperate peril, we kind of wish the Fellowship could thoroughly explore Moria, don’t we? And when we hear the phrase ‘delved too greedily and too deep’, we want to know what’s down there, what they found, what the dwarves discovered, don’t we?