Old-School Essentials Adaptation Guidelines

Over the last two decades, a large number of old-school adventure games have been published, many of which—like Old-School Essentials—are closely compatible with the 1981 Basic/Expert rules.

While each of these games has its own variations on rules, presentation, and terminology, many are high cross-compatible. This cross-compatibility between games means that a great wealth of adventures, campaign settings, and rules supplements written for other old-school systems can be used with Old-School Essentials. Material written for Old-School Essentials can likewise be used with many other old-school systems.

This document provides guidelines for using material written for some of these systems with Old-School Essentials, and vice versa.