Thread:OParris2017/@comment-104549-20180419222004/@comment-104549-20180419224221

The policy isn't that permissive, although it's not overly restrictive either. The allowance for borrowing concepts means, for example, you could have a society with a rule that prohibits interference with the development of alien civilizations ( ' s ). By contrast, you could not have Captain Kirk and the Enterprise joining forces with Luke Skywalker and the Rebellion.

The Crossover Policy doesn't usually impact images; if, for example, you wanted to use an image of Master Chief (and concluded it was a Fair Use as a screenshot), you could do that, but it can't be Master Chief from Halo. Just as many users use canonical pictures of Anakin Skywalker and call it a different character—and that's okay—as long as a proper licensing template exists, you can use images from other media to represent your characters and creations, regardless of what they are in their original universes.

Earth is a sui generis thing; since the Star Wars saga is explicitly set in "a galaxy far, far away", that does imply that Earth exists in the same universe as the Star Wars galaxy. Therefore, the use of actual Earth is generally okay. However, a user could not have Star Wars characters meet John McClane; even though Die Hard is set on Earth, it's still fictional, and so it would be another fictional universe crossing over.

Hope that helps to clarify what the Policy does (and doesn't) reach. If you have specific questions, let me know.