A flat leather wallet or rolled cloth sleeve holding a dozen slender tools for defeating locks without their keys: hook picks in several profiles for single-pin manipulation, serrated rakes for quick work against cheaper wards, tension wrenches of assorted sizes, a fine hooked probe for extracting broken picks, and usually a sliver of polished tin for peering into a keyway. The kit is built for stealth — flat, small, and silent enough to ride inside a boot, a belt lining, or a false pouch bottom, and to be drawn one-handed in near darkness. It is the tool of burglars, spies, and cracksmen-for-hire; in most realms, possession alone is sufficient evidence for a magistrate to convict, and a thief caught with one can expect a flogging at best and a hanging at worst.
Using a lockpicking kit effectively requires training in Legerdemain. A novice armed with one will do little better than an ordinary person with a bent nail, and in the hands of the unskilled the picks are more likely to dull or snap than to find the pins. Even a master’s picks wear quickly against iron wards and can break under aggressive tension, so a careful thief carries spares of the most-used profiles and replaces them before they fail. The loss of even a single pick from the set leaves a gap that may cost a job at the wrong moment.