Generally this happens when pages are either blanked by the author, which means a speedy deletion by the admins or a discussion on a file or page over why it should be deleted is in the respective talk page concludes it must go.
This wiki's deletion policy info.[]
- It is just trolling and Vandalism.
- The creating/care taking author(s)'s request(s) to have there page removed on request.
- Broken/Unused redirect.
- It is a clear breach of copy right.
- A long unused game. Say, ignored for over a year.