Null Signal Games has been publishing new sets for the 2012 Netrunner living card game since Fantasy Flight Games lost their license in 2018. How are Null Signal Games able to publish content for a game made by another company without violating copyright?
For context, Wizards of the Coast (owned by Hasbro) made a version of the Netrunner game in the 1990s that was discontinued (this is what I'm calling "1990s Netrunner"). Wizards of the Coast sold Fantasy Flight Games a license to make a new version of the game, which Fantasy Flight Games produced from 2012 to 2018 (this is what I'm calling "2012 Netrunner"). Null Signal Games is producing cards that work with the rule set of 2012 Netrunner. Beyond that, Null Signal Games is using the same game concepts (ICE, Icebreakers, Assets, Upgrades, Identities, etc.) and a nearly identical rules set as Fantasy Flight Games was. How is there no violation of Fantasy Flight Games's copyrights here?
The cards appear to be using nominally different art assets and layouts. Just comparing an Null Signal Games card (ex. https://netrunnerdb.com/en/card/34020 or https://netrunnerdb.com/en/card/31027) to an Fantasy Flight Games card (ex. https://netrunnerdb.com/en/card/25040 or https://netrunnerdb.com/en/card/01034), they're using different faction logos, a different font, slightly different colors, and have replaced all of the symbols with very similar but nominally different symbols. They also appear to not be using the Android setting that Fantasy Flight Games used for 2012 Netrunner.
But if all that was enough, why did Fantasy Flight Games need to license the game from Wizards of the Coast in the first place? 2012 Netrunner looks nothing like the 1990s Netrunner (see http://www.playthepast.org/?p=3574 for a comparison). Given Fantasy Flight Games needed a license from Wizards of the Coast to make even a thematically related game to the 1990s Netrunner, why doesn't Null Signal Games need one?
Null Signal Games commented in an AMA on Redit:
I can't go into the details (and am not a lawyer, so would probably word something wrong even if I could) but our lawyers are comfortable with what we're doing.