Licensing
The C22 System is released under the Creative Commons Attribution 4.0 International license (CC BY 4.0).
To license the system, you just need to include either of the following excerpts near the copyright for your game.
This work is based on the C22 System (found at https//www.c22system.com), a product made by Pagoda Games, designed and written by Brandon Gutowski, and licensed for our use under the Creative Commons Attribution 4.0 International License.
If you are keeping a major portion of the rules and your work primarily adds a setting to the rule set, the following excerpt would be a better representation along with the wording following your title βis a C22 System.
This work is a C22 System (found at https//www.c22system.com), a product made by Pagoda Games, designed and written by Brandon Gutowski, and licensed for our use under the Creative Commons Attribution 4.0 International License.
Logo
To use the either of the C22 logos legally, you must include the following
C22 System is property of Pagoda Games. The C22 logo is used with permission.