Free content depends on licenses that do not restrict four freedoms. The Free RPG Community recommends the GNU General Public License (GPL) for your free content works, as it is the most established, legally sound and reliable.

The Free Software Foundation also maintains a list of other free software licenses. Some other free content licenses endorsed by the Free RPG Community include:

GNU Free Documentation License

The GNU Free Documentation License (GFDL) is a free content, GPL-incompatible license for "free documentation" published by the Free Software Foundation as an alternative to the GPL for technical documents.

Please note that documents which use Invariant Sections (unmodifiable, non-removable parts of a document) are not free content. For this reason we recommend you use the GFDL without Invariant Sections, or use the GPL instead.

Non-Free Content Licenses

The Free Software Foundation also maintains a list of non-free software licenses. There are some content licenses that claim to be free or 'open' but, in fact, impart few or none of the free content freedoms. These include:

Open Gaming License

The Open Gaming License (OGL) is a weak copyleft license published by Wizards of the Coast. It allows user's to define parts of a work to be copyleft, or "Open Gaming Content" (OGC). The OGL cannot be considered a free content license for the following reasons:

Firstly, Section 8 of the OGL restricts distribution of OGC as software, and possibly other forms of distribution. This directly contradicts the freedom to adapt the work, for example, by prohibiting the distribution of OGC as binary executables or software libraries.

Secondly Section 7 also restricts licensees from claiming compatibility with any trademarked work containing OGC, restricting the freedom to adapt the work by denying your right to claim compatibility with other systems.

Lastly, we note that excessive use of Product Identity and the practice of mixing OGC with "closed content" without clear identification can never be considered free as we define it.

For these reasons we ask you to avoid the OGL.

Creative Commons Public License

This is not one license, but a series of variant, GPL-incompatible licenses with different options. Only the BY (ByAttribution) and BY-SA (ByAttribution and ShareAlike) licenses can be considered free.

There may also be several issues with the 2.0 and 2.5 versions of these licenses that prevent them being free. Until these issues are resolved in the upcoming 3.0 versions of these licenses we ask you to avoid any Creative Commons license.