I'm kicking around the idea of writing a game that would be based on the Dwarf Fortress style/lore. Are there any official statements or even an official license from the Adams brothers covering the creation of derivative works in the Dwarf Fortress universe? Obviously anybody can make a game about dwarves digging holes in the ground, but DF is my inspiration and explicit callouts to the DF universe would be fun.
For example, Wizards of the Coast manage the Dungeons & Dragons intellectual property, and they have an explicit license called the Open Game License that allows anyone to make certain kinds of derivative works in the Dungeons & Dragons universe:
https://dnd.wizards.com/articles/features/systems-reference-document-srdI'm not looking to make a lot of money, but definitely interested in running ads to offset hosting costs if this were to go anywhere.