Board Thread:Support Requests - Getting Technical/@comment-1938331-20140528163236/@comment-452-20140528164758

Wikia Staff will not like you disabling the main page cache.

It would probably be best for you to use javascript to do the random selection, that way, everything can be cached, but it will still appear random. (Even if the javascript loads a cached page containing the list of featured articles, that's still better than having the main page uncached.)