A Guide to Thieves' Guilds

From publisher blurb: This book provides an abstract system for running thieves' guilds in any OSR-style game. While written for Old School Essentials, the system contained is easily adapted to other rulesets. It provides guidelines for establishing and recruiting for a guild, generating revenue, and resolving conflicts with rival Guilds, with a focus on higher-level play for thief and assassin characters.