In Basic Dungeons and Dragons, and in the first and second editions of Advanced Dungeons and Dragons, a character class dedicated to the art of stealth. Their larcenous abilities were (in all these editions of the game) characterised as a set of percentile scores, much like character skills in Call of Cthulhu. Initially, these scores were fixed by a big, scary table, but by the time of Second Edition it was allowable to vary them by alloting points from a pool. Thieves also traditionally required the least XP to advance levels.

In Basic, where the names of the classes and alignments were a semantic minefield, there were no alignment restrictions on thieves, but it was left unclear as to whether a thief had to, er, thieve. In later editions, thieves have had to avoid certain alignments - notably Lawful Good. In First Edition there was also a thief-acrobat class, introduced in Unearthed Arcana and of doubtful value. In Second Edition, Thieves were part of the Rogue class group. In the new Third Edition, the Thief class has been renamed Rogue.