The term “thief” comes from the Lithuanian word “tupeti” which means to crouch down (Ayto 1990). As mentioned previously, the thief has strong connotations with both hobbits and dwarves. The thief class presents a manner of approach to adventuring “that is basically individualistic and unobserved (as differing from indirect).” (Gygax 1987).
Although there are always thugs, bandits, pirates, and assassins of all stripes, it is the thief who has been singled out as a hero (if not heroic) archetype (Aeon 2001). Part of the thief’s appeal is his everyman quality, and it is that same quality that manifests in hobbit thieves. If hobbits are the everyday farmer, the thief is a starving farmer who has to resort to desperate measures to survive. He is us, fallen on hard times.
The thief first appears in Dungeons & Dragons in the Greyhawk supplement. Their skills include opening locks, disabling traps, listening for noise behind closed doors, moving quietly, picking pockets, hiding in shadows, striking silently from behind, and climbing sheer surfaces. At 10th level they are able to read scrolls, with a 10 percent chance of 7th-level or higher spells backfiring on the thief. (Gygax 1976)
Beyond Tolkien, Gygax drew upon several sources for the Dungeons & Dragons-style thief. There is the adventurer in Fritz Leiber’s Gray Mouser, who debuted along with his barbarian ally Fafhrd in Two Sought Adventure (1957). The Gray Mouser shares the thief’s penchant for daggers and the ability to wield them against unwary adversaries. There is also Jack Vance’s “Cugel the Clever” (Wetzels) and Roger Zelazny’s “Shadowjack”. This varied heritage explains the thief ability to read scrolls in the early editions of Dungeons & Dragons. It’s evident that the thief archetype harkens from a more cynical, pulp-like fantasy setting, a setting that certainly inspired Gygax, who was a fan of Vance’s work (Gygax 2001).
The thief has a particularly important role in the creation of interactive fiction; two of the programmers who helped create Zork played thieves. They valued exploration and puzzle solving, challenges eminently suited to the thief role. When dungeon crawling was the preferred mode of adventure, dungeons often had traps that could only be surmounted through a thief using his ability to detect traps and disarm them.
This fascination with the thief class continued in Zork, with the creation of one of the first non-player characters controlled by a computer, the ever-present thief, described as “a seedy-looking individual with a large bag” and “a man of good breeding.” (Montfort 2003). The thief was an adept pickpocket who would wander in, steal an item from the player, and leave – all features common to Dungeons & Dragons thieves. These traits made the Zork thief a constant irritation to the player and a challenging obstacle to overcome.
This description is a rough draft from my upcoming book, The Evolution of Fantasy Role-Playing Games.