If you went to the days before D&D and asked someone to name the “thievish” characters of fantasy literature, they would say Cugel the Clever (1965) and the Gray Mouser (1968). A particularly well read person might mention Lord Dunsany’s Mr. Nuth (1912). Some might have been tempted to mention Bilbo Baggins (1937), but they would be wrong; Bilbo only pretended to be a burglar.
Cudgel and the Mouser have something in common: they’re both magic-users. Whether or not Mr. Nuth used magic is up for interpretation. Lord Dunsany writes that “To those outside the magic circle of business, his name is scarcely known,” so it certainly seems plausible.
It seems odd to me, then, that D&D thieves are not magic users. So in my world, they are! This isn’t a hard leap to make. When you look at a thief’s core abilities, it becomes apparent most of these abilities already exist as spells.
Core abilities
The thief class is first introduced in 1975’s Greyhawk supplement. In that volume they’re given the following basic abilities: