Duelyst

A hybrid online turn based-strategy/Collectable card game originally released in April 2016, the code and assets were relicensed as Creative Commons Zero in 2023

Video announcement
In a video published on Youtube on 2023-01-10 Richard Heyne (JuveyD) the Lead Producer Counterplay Games announced “Starting today Counterplay Games is making our tactics meets collectible card game Duelyist open source and available for anyone in the community to extend, modify, and build with free of charge and royalties. This means that all of the source code and art assets we've developed at Counterplay Games are available royalty free on the GitHub link below for you indie developers, hackers, modders, and hobbyists to modify, extend, and remix to your heart's content. This means you can release your own version of Duelyst. You can make your own card designs, run your own servers, and author your own game modes.”