The Complete Thief's Handbook is a rules supplement for the 2nd edition Player's Handbook which details the thief class. The book includes rules for locks and traps, poisons, animal assistance, new proficiencies (skills), and special equipment; also covered are 18 "thief kits" (subclasses) such as the assassin, burglar, spy, and investigator. This book includes guidelines for role-playing thieves of different races and backgrounds; how a thieves' guild works and how to design one; handling con jobs; and running a campaign for groups of thief characters.
Also included is a section on creating a "Lone Wolf;" essentially a one-character class designed using the class creation rules in the Dungeon Master's Guide. A sample Lone Wolf character is included as a demonstration of the process.