Where did the concept of a (fantasy-style) "dungeon" originate?

Question

Everyone knows what a dungeon is: it's a dank, bleak underground jail where medieval prisoners get locked up.

Unless you're in a fantasy story, of course! In that case it's an area, generally underground, that's full of monsters guarding treasure, a great place to go adventuring, and hardly ever has anyone locked up in it.

This use of the term obviously goes back at least as far as the original Dungeons & Dragons, (it's right there in the name,) but where did D&D get it from?

Where was the word "dungeon" originally used to denote an adventuring destination rather than a prison?

Answer 1

As per this RPG SE question, the first adventure was in a dungeon under a keep, and the name stuck.

According to Gary Gygax (in an interview with Dungeon #112), the first dungeon crawl was part of a wargame in which the invading force entered the enemy's castle through a former escape tunnel dug from the fortress's dungeon. The group had so much fun with this scenario that it was repeated over and over with increasingly complex dungeons until the wargame aspect of the game was dropped in favor of exploring the dungeon

Add to that that Dave Arneson's preferred setting were the dungeons under the castle of Blackmoor, and the fate of the term was pretty much sealed.

Answer 2

The word dungeon derives from the French donjon for a central tower (or keep) in a castle, and the latter word is still used in this sense in English. It is possibly derived from the Latin dominus "lord, master". Dungeon later came to be (mis)used as the name for a cell or oubliette, often situated in the lower floor or basement of a keep.

I believe that Dungeons & Dragons may be the first instance of the use of dungeon to mean larger caverns or catacombs, though it should be noted that most of the early adventures took place in the basements of towers of castles or in ancient tombs rather than actual caverns, making the use of the word less of a misnomer. I imagine that the way way the word alliterates with dragons is a factor; Crypts & Dragons just doesn't have the same ring to it.

As for the origin of "dungeons" as a venue for fantasy adventure, I believe that The Hobbit (1937) was the main inspiration for Gary Gygax, who adored the book, but didn't care much for The Lord of the Rings. In The Hobbit, Bilbo has a lengthy underground adventure in the Misty Mountains where he runs into Gollum, then beneath the castle of the wood elves, and again in The Lonely Mountain, where he runs into Smaug - we hence have both a dungeon and a dragon.

As Lucas Backmann wrote in a comment above, Edgar Rice Burroughs may also be an influence, and his heroes do tend to be trapped underground, but their main adventure seems to be to find a way to escape rather than fighting monsters or finding treasure. In fact, The Hobbit has all the main elements of Dungeons & Dragons, also including the four classic D&D races, orcs, a thief (of sorts), wizards, magic swords that glow in the presence of enemies, mithril armor and a Ring of Invisibility.

Another possible influence is Robert E. Howard's stories of Conan and King Kull, who also have their share of underground adventures.

Answer 3

While Gary Gygax's Chainmail wargame (the predecessor to D&D) seems to be the most direct origin of the term "dungeon crawl" in tabletop RPGs, the term "dungeon" does appear in earlier fantasy works, such as Tolkien's books, in contexts that may or may not refer to a prison or torture chamber as such.

The most famous is probably the refrain from the untitled song the dwarves sing in The Hobbit:

Far over the misty mountains cold

To dungeons deep and caverns old

We must away ere break of day

To seek the pale enchanted gold

(The last line varies with each repetition.)

But the term is also used occasionally in Lord of the Rings where it's not clearly referring to a prison:

"Ever up now we went until we came to the Endless Stair. [...] From the lowest dungeon to the highest peak it climbed..."

Another dreadful day of fear and toil had come to Mordor; and the night-guards were summoned to their dungeons and deep halls, and the day-guards, evil-eyed and fell, were marching to their posts.

Now those could mean literal dungeons, but arguably, by the 1950s, the term was already shifting in use to indicate merely the underground portions of a structure rather than a particular intended function.