@EmoIsDeadAndSoAmI @david I was clearly referring to the nonfree software games.

Free software games with nonfree art are quite easy to spot.

When it comes to art and the like, when encoded in a free image format, there's nothing you can really do to stop people from sharing it or modifying it, while you can restrict people from modifying software by not including the source code.


A book is not a functional work and there is nothing functional you can really do to stop people from sharing or modifying books if they have the book text.

There are quite a few books under free licenses that you can read.