Board Thread:Support Requests - Designing Your Wikia/@comment-28122555-20140817135015/@comment-168424-20140823150808

Doing this so other users can see it requires you to be an admin, I believe, but you can test it with adding CSS to Special:MyPage/wikia.css.

The best way to show how to do this would be on your wiki (not community).

In general the CSS looks like this: .page-PAGE_NAME { background: url('backgroundimage.jpg'); }

PAGE_NAME is the name of the page as it appears in the URL with underscores instead of spaces.