All visual and audio assets are licensed under the Creative Commons BY-SA 4.0. The contributor always retains the full rights to their own work and can continue to use it however they wish.
Unless explicitly stated otherwise, all visual and audio assets that are posted to the Art forum are considered as potential contributions and are automatically placed under the CC BY-SA 4.0.
Visual and audio assets for which you do not own the rights cannot be accepted, nor can any derivative works, nor anything that falls under fair use.
Code contributed to Project CardBoard is licensed under the GNU GPLv3 or later. This includes all code, whether it be Java, Python, or any other language that is currently part of the project or is added in the future. This also includes data files, such as maps, as well as story content.
See the main project repository's COPYRIGHT file for more information. This repository is a subsidiary of that main project.