The d20 System The Official Website of the d20 Game Engine and the Open Gaming License

This site maintains the most current versions of the the Open Gaming License, d20 System Reference Document, the Modern System Reference Document, the Arcana System Reference Document, the d20 System Trademark License, the Open Gaming License, and the d20 System Trademark Guide. It also provides answers to frequently asked questions about them (FAQs).

The d20 System is the game engine used in Wizards of the Coast's hobby gaming roleplaying games. The d20 System was used as the root of the System Reference Document (SRD), an abstract version of the rules and nonrule content of the various d20 System roleplaying games from Wizards.

Message Boards

• d20 System
• Dungeons & Dragons
• Forgotten Realms
• Eberron
• d20 Modern
• Star Wars

Official Licenses

• Open Gaming License (12k RTF)
• d20 System License 6.0 (12k RTF)
• d20 System Guide 5.0 (788k RTF)
• Electronic SKU Download (ESD) Conversion Agreement (12k RTF)

System Reference Document

• SRD Main Page
• d20 Modern SRD Page

Official d20 System FAQs

• Concept FAQ
• Trademark FAQ
• SRD FAQ

Official Open Gaming License FAQs

• Open Game Definitions
• Open Gaming Foundation
• Open Gaming License
• Other Licenses
• Software FAQ

For Publishers

• License confirmation card (72k PDF/ZIP)