Octas/fallen is the fantasy-themed genre-expansion for the Octas game. The mechanics files in the 'fallen' section (Menagerie, Equipment, Magic), the sample adventure "Beyond the Gates" and the Appendix "Behind the Curtain" are released under the Open RPG Creative License (ORC):
ORC AxE (Answers and Explanations)
You may freely use the above documents and their contents in the creation of your own Octas game materials.
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Any other 'Adventure Modules' present are licensed separately within their documents.