As mentioned on the landing page, OSR games (OSRIC, For Gold and Glory, etc.) are the focus of this jam. Submissions should be usable with one or more.
This said, all editions of Dungeons and Dragons (OD&D, B/X, BECMI, AD&D 1st Edition, AD&D 2nd Edition, 3rd, 4th and 5th Edition) are viable as well.
- Copyrights and Attribution -
https://www.copyright.gov/help/faq/faq-general.html
Also, when in doubt, make it free.
- OSR Logo Clipart -
Black - https://openclipart.org/detail/335996/osr-logo-black