In the First and Third Editions of (
Advanced)
Dungeons and Dragons, the Monk is a class reliant almost entirely on
martial arts for combat purposes. As they progress in
experience, they gain mystical powers, eventually becoming able to run like the wind, resist blows, and leap tallish buildings at a single bound.
In the first edition, this class made its first appearance in the
Player's Handbook, but was revised in
Oriental Adventures, and was considered by some to be
broken. In second edition, it was entirely absent, although
the Complete Cleric's Handbook had a
fighting monk character
kit. In the new Third Edition, the Monk is a core class, and appears in the
Player's Handbook, although
Sword and Fist and the new
Oriental Adventures open up more options for them.
Basic D&D's
Rules Cyclopedia featured a suspiciously similar
Mystic class. Presumably 'monk', along with 'priest', 'god', and 'evil', was a Word Not To Be Said in the old game. I am informed (by
sabby) that the mystic originally appeared in the Master Rules Boxed Set.