From the introduction: This Source Reference Document (SRD) is an expansion for the SE:20 Core Rules SRD. You need to be familiar with those rules before you can use this book. Publisher's blurb: This free-form magic system allows you to create new spells, powers, etc. as needed in the game. User summary: Despite being designated as a "System Source Reference Document", The Magic & Powers SRD provides the game options without any re-use option or license option. Additionally, "SRD" use is restricted by copyright which exclusively prohibits anything except "personal use".