Open Game Development System Reference Document

Publisher's blurb:

I created the Open Game Design System Resource Document to help gamers and developers create games and worlds that are compatible and also to give them a simple platform off of which to build their own games and worlds. It is released under the Creative Commons share alike commercial and non-commercial license but has a special permission for copyrighted material like logos, artwork etc.,. This means you should be able to use the rules and others will be able to use your rules but won't be able to publish your logo, artwork or other copyrighted works. This is a version of an OGL. The system itself is based off of a game I designed in the 90s before there was an OGL.