Monks in AD&D

 I don’t like them because they’re directly based on the main character of the movie “36th Chamber of Shaolin”, and don’t fit any fantasy milieu that aren’t in Henan Province, China.

But I have to begrudgingly admit that they occupy an important place mechanically by essentially being an upgrade class to the Thief. The four “base” classes of Fighter, Cleric, Magic-User and Thief are fairly bland, and the “advanced” classes like Ranger, Paladin, Assassin and Druid are much more attractive. The Fighter especially is like a consolation prize for characters that don’t meet the stat requirements of any other class, and the base Thief is very weak. The only exception is the Magic-User. 

The Assassin is basically a ninja before OA, and has a ninja’s list of weapon proficiencies. Monks and Assassins fill the “striker” role of inflicting massive damage with regular weapons and special skills, instead of magic, and this role is basically what the Rogue class became from 3rd edition on.

The Monk is the only way to play a Lawful class with Thief skills, without multiclassing. I think it’s a mistake to drop monks to a level 1 character if they break alignment, they should drop to a Thief of the same level, in the way Paladins and Rangers drop to Fighter.