Classing Up The Joint (d20)
Classing Up the Joint is written for Necrotic Gnome's Old School Essentials but can be easily adapted to any OSR-style game. It provides a basic framework for determining the XP requirements of custom classes.
This document has been revised and compiled as part of Into the Wild¸ a book containing five of the free or lower cost document I have put out: Classing up the Joint¸ Domain Building¸ Hexcrawl Basics¸ Random Weather Generation¸ and Wealth by NPC Level. /p>