You get an interesting collision between two expectations on licensing in a modding community for an open source game.
Modding communities have historically leaned on self-penned bespoke licences tending toward the, "only Tool fans can use this! Do not rip my sprites without permission, that means you XxSephiroth494 YOU HAVE BEEN WARNED!!" school of legal text. But as an open-source project, there is a convention to upload things to the content distribution network with a GPL or Creative Commons licence.
This causes some rather dramatic fallouts when "I don't have to give you any source code, it's mine and I wrote it" or "he can't just take my mod and build his own version of it" meet the inevitable response of, "you released it under the GPL, that's how it works". It gets rather messier when said work includes upstream things which were originally released under the Tool Fan Restricted Licence or similar where the original creator forbade further sharing of source code.
Modding communities have historically leaned on self-penned bespoke licences tending toward the, "only Tool fans can use this! Do not rip my sprites without permission, that means you XxSephiroth494 YOU HAVE BEEN WARNED!!" school of legal text. But as an open-source project, there is a convention to upload things to the content distribution network with a GPL or Creative Commons licence.
This causes some rather dramatic fallouts when "I don't have to give you any source code, it's mine and I wrote it" or "he can't just take my mod and build his own version of it" meet the inevitable response of, "you released it under the GPL, that's how it works". It gets rather messier when said work includes upstream things which were originally released under the Tool Fan Restricted Licence or similar where the original creator forbade further sharing of source code.