House Rules for 0e Games From the introduction: This booklet is full of house rules – modern versions of the house rules I first used in my 0e campaigns in the 1970s and still use today. While each GM may certainly pick and choose which rules will be used in their campaigns, many of the rules sections assume that other rules in this tome are being used. User summary: While the rules formatting and presentation formally follows the Swords & Wizardry "old school" game, the item is compatible with any of the various "retro clone" products available. Most of the house rules are modular and fairly simple to implement; some have much greater scope.